Ihsan Erdin
Carleton University, Electronics, Adjunct
- Ihsan Erdin received his masters degree from METU, Ankara in 1993 and the Ph.D. from Carleton U. Ottawa in 2001 both ... moreIhsan Erdin received his masters degree from METU, Ankara in 1993 and the Ph.D. from Carleton U. Ottawa in 2001 both in electrical engineering. Since 2000, he worked as a signal and power integrity engineer at Nortel and Celestica where he contributed in the development and design analysis of data communication circuits and systems of multiple generations. In addition to his current position at Celestica, he is an adjunct faculty member at the Electronics Department of Carleton University. In 2018 and 2019, he served as an IEEE EMC Society's Distinguished Lecturer. Currently, he serves as a member of the Signal and Power Integrity Technical Committee (TC-10) of the IEEE EMC Society. His research interests are analytical and computational electromagnetic methods with application to printed and integrated circuits. He contributed to research efforts with dozens of technical publications and reports in this field. Ihsan is a member of the Professional Engineers Ontario and a senior member of IEEE.edit
A Newton-Raphson (N-R) based method is developed for performance evaluation of power delivery networks (PDN) with arbitrarily shaped parallel-plate power/ground plane pairs. The proposed method allows for PI assessment in a few iteration... more
A Newton-Raphson (N-R) based method is developed for performance evaluation of power delivery networks (PDN) with arbitrarily shaped parallel-plate power/ground plane pairs. The proposed method allows for PI assessment in a few iteration steps while providing significant computational efficiency compared to alternative methods. The proposed method is tested on a practical example and the results are observed in good agreement with those obtained from a numerical electromagnetic (EM) simulator.
Research Interests:
Gauss-Newton (G-N) based method is proposed for optimal placement and performance evaluation of local decoupling capacitors on resonant parallel-plates. Multiple power pins are used as a leverage for simultaneous placement optimization of... more
Gauss-Newton (G-N) based method is proposed for optimal placement and performance evaluation of local decoupling capacitors on resonant parallel-plates. Multiple power pins are used as a leverage for simultaneous placement optimization of multiple capacitors by utilizing matrix calculus methods. The algorithm converges in a few iterations, which is a big improvement against the competing evolutionary methods. The proposed method is tested on a sample case and the results are observed to be valid across a practically wide frequency range.
A method is proposed to calculate the effectiveness of a decoupling capacitor in the presence of other capacitors. The previously developed scalar expressions for calculating the effective radius of a capacitor in isolation are extended... more
A method is proposed to calculate the effectiveness of a decoupling capacitor in the presence of other capacitors. The previously developed scalar expressions for calculating the effective radius of a capacitor in isolation are extended to matrix relations which account for mutual coupling. In the same vein, the scalar operations are substituted by their matrix counterparts including the calculation of derivatives using matrix calculus techniques which are required for the iterative solution of the problem. The proposed method is tested on a sample case and the results are observed to compare favorably against those from a numerical electromagnetic (EM) simulator.
A fast and efficient method is proposed for placement of decoupling capacitors on printed circuit boards (PCB) with resonant parallel planes. Using the pin impedance as a fitness function, a genetic algorithm (GA) based method is used for... more
A fast and efficient method is proposed for placement of decoupling capacitors on printed circuit boards (PCB) with resonant parallel planes. Using the pin impedance as a fitness function, a genetic algorithm (GA) based method is used for simultaneous optimization of capacitors' placement with respect to ball-grid array (BGA) pin fields. The proposed method applies to practical PCB designs without restriction on the number of power pins or planar geometry. The developed algorithm is tested on an industrial example in comparison to a numerical electromagnetic (EM) simulator. The results are shown to agree well while significant speed-up is obtained with the proposed algorithm.
An analytical model is developed for the driving point impedance of a power pin for the evaluation of a decoupling capacitor's effectiveness. The model accounts for the finite sized parallel-plate ground-power pairs and is validated... more
An analytical model is developed for the driving point impedance of a power pin for the evaluation of a decoupling capacitor's effectiveness. The model accounts for the finite sized parallel-plate ground-power pairs and is validated against a numerical electromagnetic method. The proposed method is also used in the assessment of pin impedance in a comparative study involving multiple representative locations of a power pin on a rectangular plane. In addition to the pin-capacitor distance, the angular dependency of impedance is demonstrated in the evaluation of the capacitor's effectiveness and a physics based explanation is provided using the developed expression. From the interpretation of the results, a generic design rule is proposed for the placement of decoupling capacitors on parallel-plates.
A method is proposed for efficient placement of decoupling capacitor on a power transmission line based on calculating the critical distance between device power pin and the capacitor. The critical distance is measured from the power pin... more
A method is proposed for efficient placement of decoupling capacitor on a power transmission line based on calculating the critical distance between device power pin and the capacitor. The critical distance is measured from the power pin and refers to the spacing for which the capacitor's effectiveness is reduced by a predefined amount with respect to the power pin. The resulting transcendental equation is solved for the distance using an iterative approach. The proposed method is validated by comparing to full wave electromagnetic simulation results.
A new method is developed to assess the effectiveness of local decoupling capacitors on parallel-plate power and ground conductors. The proposed method calculates the loop-inductance of multiple capacitors including their mutual... more
A new method is developed to assess the effectiveness of local decoupling capacitors on parallel-plate power and ground conductors. The proposed method calculates the loop-inductance of multiple capacitors including their mutual interactions and the effect of power and ground vias. The underlying theory is based on computing the driving point impedance of a device power pin which serves as a reference in the evaluation of capacitor's effectiveness. The accuracy of the proposed method is validated by comparing the results to those from a full-wave electromagnetic simulation.
Pin-capacitor distance is studied for the efficiency of local decoupling capacitors in power delivery networks (PDN) designed as power transmission lines. The inefficiency of remote decoupling capacitors is explained with a physical... more
Pin-capacitor distance is studied for the efficiency of local decoupling capacitors in power delivery networks (PDN) designed as power transmission lines. The inefficiency of remote decoupling capacitors is explained with a physical insight using the fundamental principles of transmission line theory. The proposed model conforms well to general observations and is supported by numerical examples.
A novel approach for evaluating the efficiency of decoupling capacitors is proposed for power delivery networks (PDN). The method relies on the spacing measured from a device reference point to the nearest capacitor and can be used as a... more
A novel approach for evaluating the efficiency of decoupling capacitors is proposed for power delivery networks (PDN). The method relies on the spacing measured from a device reference point to the nearest capacitor and can be used as a guide for the placement and optimization of local decoupling capacitors on chip, package or PCB medium. Simple relations are developed including the mutual interaction between components and their accuracy is validated by a case study.
A new model is proposed to explain the effectiveness of decoupling capacitors in relation to their proximity to device power pins. The proposed approach applies to power delivery networks (PDN) designed as parallel-plate power ground... more
A new model is proposed to explain the effectiveness of decoupling capacitors in relation to their proximity to device power pins. The proposed approach applies to power delivery networks (PDN) designed as parallel-plate power ground plane pairs. The effectiveness of capacitors is explained through the device pin input impedance which can be expressed as a function of spatial coordinates. The proposed method conforms well to general observations and is validated by numerical examples.
The input-to-output transfer function of a buck converter is investigated including power transmission line parameters, accounting for printed circuit board (PCB) parasitics. A closed-form relation is developed for the transfer function... more
The input-to-output transfer function of a buck converter is investigated including power transmission line parameters, accounting for printed circuit board (PCB) parasitics. A closed-form relation is developed for the transfer function to be used in small-signal analysis. Also, the effect of power transmission lines is demonstrated on control-to-output transfer function of the converter.
In this paper, a new formulation is provided to model the noise coupling between adjacent planes in a multilayer stackup. A model is developed to show that the planar coupling depends heavily on the wave impedance of each power plane.... more
In this paper, a new formulation is provided to model the noise coupling between adjacent planes in a multilayer stackup. A model is developed to show that the planar coupling depends heavily on the wave impedance of each power plane. Also a rigorous investigation of planar noise coupling with respect to the separation distance between the planes and use of decoupling capacitors is presented. The validity of the developed model is successfully tested on sample structures.
In this paper, the ac small-signal relations of commonly used DC-DC controllers such as buck, boost and buck-boost are extended to include distributed PCB effects. The critical parameters of these controllers including input-to-output,... more
In this paper, the ac small-signal relations of commonly used DC-DC controllers such as buck, boost and buck-boost are extended to include distributed PCB effects. The critical parameters of these controllers including input-to-output, control-to-output transfer functions and the output impedance impacting power and EMC designs are derived. Using the newly developed broadband model, the effect of PCB parasitics are investigated and compared to the conventional relations.
The design parameters of a buck converter are investigated based on ac small-signal design parameters such as open-loop, input-to-output and control-to-output transfer functions including distributed circuit parameters that account for... more
The design parameters of a buck converter are investigated based on ac small-signal design parameters such as open-loop, input-to-output and control-to-output transfer functions including distributed circuit parameters that account for PCB parasitics. It is demonstrated that the PCB effects neglected in a 2 nd order model could affect the design parameters such as selection of switching frequency. The relations developed in this work are validated in the power design of an idustrial circuit and compared to the conventional 2 nd order models.
A method is proposed for the optimized placement of decoupling capacitors on power delivery networks (PDN) involving irregularly shaped power-ground plane pairs. The method is based on an evolutionary optimization algorithm that uses the... more
A method is proposed for the optimized placement of decoupling capacitors on power delivery networks (PDN) involving irregularly shaped power-ground plane pairs. The method is based on an evolutionary optimization algorithm that uses the driving point impedance of device power pins as the fitness function. The plane pairs are modeled with their distributed models including the capacitors. A generalized form of segmentation method is used to account for the capacitive loading of the planes. The proposed algorithm eliminates the commonly used two-step approach in power integrity (PI) analysis and is shown to be particularly useful as a single operation in the optimization of power delivery networks for the selection and placement of decoupling capacitors. The proposed method is validated in comparison to a numerical electromagnetic (EM) simulator and tested on a practical design example.
The segmentation method used for the analysis of arbitrarily shaped planar structures is extended to a more general form to account for capacitive loading between parallel plates. In power integrity (PI) analysis of power delivery... more
The segmentation method used for the analysis of arbitrarily shaped planar structures is extended to a more general form to account for capacitive loading between parallel plates. In power integrity (PI) analysis of power delivery networks (PDN), the capacitive loading represents decoupling capacitors between power and ground planes. The algorithm is geared to the analysis of PDNs for performance evaluation, selection and placement of decoupling capacitors. For linear circuits, the proposed integrated algorithm eliminates the commonly used two-step approach. In the case of nonlinear loads, the algorithm helps to reduce the size of modified admittance matrix (MNA) and relaxes the burden of following circuit simulation. The proposed method is validated in comparison to a numerical electromagnetic (EM) simulator.
A compact relation is developed based on the indefinite impedance matrix. The proposed technique generalizes the application of the segmentation method to arbitrarily shaped planar structures including the effect of lumped circuit... more
A compact relation is developed based on the indefinite impedance matrix. The proposed technique generalizes the application of the segmentation method to arbitrarily shaped planar structures including the effect of lumped circuit components. The components are accounted for by modifying the previously used terminal relations in the development of the segmentation method. The proposed algorithm targets power integrity (PI) applications in printed circuits and integrated circuit packages. By direct computation of distributed circuit parameters of planar power delivery networks (PDN) including discrete components, the need for a second phase circuit simulation is eliminated. An application of the proposed method is demonstrated on a practical circuit and the results are validated in comparison to a numerical electromagnetic (EM) simulator.
Analytical models of high-speed interconnects are becoming increasingly important due to the large number and repetitive nature of signal integrity simulations. In this paper, closed-form relations are developed to calculate the... more
Analytical models of high-speed interconnects are becoming increasingly important due to the large number and repetitive nature of signal integrity simulations. In this paper, closed-form relations are developed to calculate the characteristic impedance of differential traces routed on asymmetrical dual stripline layers. The solution is based on Schwartz-Christoffel transformation in combination with the partial capacitance concept. Numerical examples demonstrating the accuracy of the proposed method have been presented.
Research Interests:
Research Interests:
A method based on indefinite impedance matrix application to planar circuits is developed for power delivery network characterization of high-speed/high-density data communication circuits. By utilizing the parallel plate waveguide... more
A method based on indefinite impedance matrix application to planar circuits is developed for power delivery network characterization of high-speed/high-density data communication circuits. By utilizing the parallel plate waveguide concept, the proposed method incorporates both ground and power via effects as well as decoupling capacitors with indefinitely many conductor layers stacked in an arbitrary order in a multilayered printed circuit board. The incorporation of analytical expressions for resonant planar circuits allows for parameterized PDN characterization and provides significant computational advantage for a follow-up PDN optimization. The method is tested on some proof of concept cases and the results are observed in good agreement with those obtained from a numerical electromagnetic simulator.
Research Interests:
Research Interests:
A method based on indefinite impedance matrix application to planar circuits is developed for power delivery network characterization of high-speed/high-density data communication circuits. By utilizing the parallel plate waveguide... more
A method based on indefinite impedance matrix application to planar circuits is developed for power delivery network characterization of high-speed/high-density data communication circuits. By utilizing the parallel plate waveguide concept, the proposed method incorporates both ground and power via effects as well as decoupling capacitors with indefinitely many conductor layers stacked in an arbitrary order in a multilayered printed circuit board. The incorporation of analytical expressions for resonant planar circuits allows for parameterized PDN characterization and provides significant computational advantage for a follow-up PDN optimization. The method is tested on some proof of concept cases and the results are observed in good agreement with those obtained from a numerical electromagnetic simulator.
Research Interests:
Research Interests:
A domain decomposition method is proposed to evaluate the effectiveness of decoupling capacitors in practical power delivery networks (PDNs). The proposed method is based on the separation of a PDN into its local and nonlocal domains. The... more
A domain decomposition method is proposed to evaluate the effectiveness of decoupling capacitors in practical power delivery networks (PDNs). The proposed method is based on the separation of a PDN into its local and nonlocal domains. The local domain is constituted by circuit components with the highest impact on the impedance of a specified power pin on a planar PDN. The rest of the PDN makes up the nonlocal domain, which could be of any planar shape. The nonlocal domain is characterized as a distributed circuit, preferably using a numerical electromagnetic (EM) simulator. The self-impedance of the pin depends on the placement configuration of capacitors in its surroundings. Using the pin impedance as a figure of merit, the optimal placement configuration is then sought in the local domain. The impact of the stationary domain is included in calculations as an indefinite impedance and the optimal placement configuration of capacitors is computed using an iterative approach. The proposed method avoids the use of a computationally intensive EM simulation at each iteration step, which significantly speeds up the analysis process.
Research Interests:
A domain decomposition method is proposed to evaluate the effectiveness of decoupling capacitors in practical power delivery networks (PDNs). The proposed method is based on the separation of a PDN into its local and nonlocal domains. The... more
A domain decomposition method is proposed to evaluate the effectiveness of decoupling capacitors in practical power delivery networks (PDNs). The proposed method is based on the separation of a PDN into its local and nonlocal domains. The local domain is constituted by circuit components with the highest impact on the impedance of a specified power pin on a planar PDN. The rest of the PDN makes up the nonlocal domain, which could be of any planar shape. The nonlocal domain is characterized as a distributed circuit, preferably using a numerical electromagnetic (EM) simulator. The self-impedance of the pin depends on the placement configuration of capacitors in its surroundings. Using the pin impedance as a figure of merit, the optimal placement configuration is then sought in the local domain. The impact of the stationary domain is included in calculations as an indefinite impedance and the optimal placement configuration of capacitors is computed using an iterative approach. The proposed method avoids the use of a computationally intensive EM simulation at each iteration step, which significantly speeds up the analysis process.
Research Interests:
A global analysis technique is proposed to calculate the effectiveness of decoupling capacitors on practical power delivery networks (PDN). The proposed method is based on separation of a PDN into its power transmission lines (PTL) and... more
A global analysis technique is proposed to calculate the effectiveness of decoupling capacitors on practical power delivery networks (PDN). The proposed method is based on separation of a PDN into its power transmission lines (PTL) and non-PTL sections. The PTL section consists of circuit components with the highest impact on the impedance of the specified power pin, including the pin itself, the nearest capacitor and segments of PTL on both sides of the capacitor. The rest of the PDN makes up the non-PTL section which could be composed of planar shapes, PTLs or a mixture of both. The non-PTL section is characterized as a distributed circuit, preferably using an electromagnetic (EM) simulator. The effectiveness of the capacitor is measured by the self-impedance of the pin which depends on the distance between them. The pin impedance is cast in a transcendental equation in the PTL section including the impedance of the non-PTL section. The optimal placement of the capacitor is calculated using an iterative approach. With the proposed method, the use of an EM simulation at each step of the iteration is eliminated, significantly speeding up the computation process. The proposed method is validated on real-life design cases.
Research Interests:
A global analysis technique is proposed to calculate the effectiveness of decoupling capacitors on practical power delivery networks (PDN). The proposed method is based on separation of a PDN into its power transmission lines (PTL) and... more
A global analysis technique is proposed to calculate the effectiveness of decoupling capacitors on practical power delivery networks (PDN). The proposed method is based on separation of a PDN into its power transmission lines (PTL) and non-PTL sections. The PTL section consists of circuit components with the highest impact on the impedance of the specified power pin, including the pin itself, the nearest capacitor and segments of PTL on both sides of the capacitor. The rest of the PDN makes up the non-PTL section which could be composed of planar shapes, PTLs or a mixture of both. The non-PTL section is characterized as a distributed circuit, preferably using an electromagnetic (EM) simulator. The effectiveness of the capacitor is measured by the self-impedance of the pin which depends on the distance between them. The pin impedance is cast in a transcendental equation in the PTL section including the impedance of the non-PTL section. The optimal placement of the capacitor is calculated using an iterative approach. With the proposed method, the use of an EM simulation at each step of the iteration is eliminated, significantly speeding up the computation process. The proposed method is validated on real-life design cases.
Research Interests:
A multi-port constrained optimization methodology is presented for the optimal placement of decoupling capacitors in power distribution networks (PDNs) of printed circuit boards (PCBs). The proposed method is based on barrier methods and... more
A multi-port constrained optimization methodology is presented for the optimal placement of decoupling capacitors in power distribution networks (PDNs) of printed circuit boards (PCBs). The proposed method is based on barrier methods and can simultaneously handle multiple ball grid array (BGA) devices and capacitor ports on practical power/ground plane pairs of polygonal shapes without restriction in the problem geometry. Semi-analytical expressions are developed for the magnitude of device port impedance that is set as the objective function. The placement optimization problem including constraints of planar boundaries and impedance specifications is cast into a matrix expression that meets Karush–Kuhn Tucker (KKT) conditions and solved through Newton–Raphson (N–R) iterations. The convergence of iterations is ensured by guaranteeing the positive definiteness of the system matrix through the Levenberg–Marquardt algorithm. Mutual coupling among multiple ports and discrete components of the problem domain is accounted for via matrix calculus techniques applied to the partial derivatives of optimization variables. The derivatives are evaluated accurately exploiting the semi-analytical relations developed for the distributed planar impedance. The proposed method is tested with several examples, and the results are observed to be in good agreement with those obtained from a numerical electromagnetic (EM) simulator while yielding significant speed-up.
Research Interests:
An analytical model is developed for the driving point impedance of a power pin for the evaluation of a decoupling capacitor’s effectiveness. The model accounts for the finite sized parallel-plate ground-power pairs and is validated... more
An analytical model is developed for the driving point impedance of a power pin for the evaluation of a decoupling capacitor’s effectiveness. The model accounts for the finite sized parallel-plate ground-power pairs and is validated against a numerical electromagnetic method. The proposed method is also used in the assessment of pin impedance in a comparative study involving multiple representative locations of a power pin on a rectangular plane. In addition to the pin-capacitor distance, the angular dependency of impedance is demonstrated in the evaluation of the capacitor’s effectiveness and a physics based explanation is provided using the developed expression. From the interpretation of the results, a generic design rule is proposed for the placement of decoupling capacitors on parallel-plates.
Research Interests:
Pin-capacitor distance is studied for the efficiency of local decoupling capacitors in power delivery networks (PDN) designed as power transmission lines. The inefficiency of remote decoupling capacitors is explained with a physical... more
Pin-capacitor distance is studied for the efficiency of local decoupling capacitors in power delivery networks (PDN) designed as power transmission lines. The inefficiency of remote decoupling capacitors is explained with a physical insight using the fundamental principles of transmission line theory. The proposed model conforms well to general observations and is supported by numerical examples.
Research Interests:
A method is proposed for efficient placement of decoupling capacitor on a power transmission line based on calculating the critical distance between device power pin and the capacitor. The critical distance is measured from the power pin... more
A method is proposed for efficient placement of decoupling capacitor on a power transmission line based on calculating the critical distance between device power pin and the capacitor. The critical distance is measured from the power pin and refers to the spacing for which the capacitor's effectiveness is reduced by a predefined amount with respect to the power pin. The resulting transcendental equation is solved for the distance using an iterative approach. The proposed method is validated by comparing to full wave electromagnetic simulation results.
Research Interests:
A method is proposed for the optimized placement of decoupling capacitors on power delivery networks (PDN) involving irregularly shaped power-ground plane pairs. The method is based on an evolutionary optimization algorithm that uses the... more
A method is proposed for the optimized placement of decoupling capacitors on power delivery networks (PDN) involving irregularly shaped power-ground plane pairs. The method is based on an evolutionary optimization algorithm that uses the driving point impedance of device power pins as the fitness function. The plane pairs are modeled with their distributed models including the capacitors. A generalized form of segmentation method is used to account for the capacitive loading of the planes. The proposed algorithm eliminates the commonly used two-step approach in power integrity (PI) analysis and is shown to be particularly useful as a single operation in the optimization of power delivery networks for the selection and placement of decoupling capacitors. The proposed method is validated in comparison to a numerical electromagnetic (EM) simulator and tested on a practical design example.
A compact relation is developed based on the indefinite impedance matrix. The proposed technique generalizes the application of the segmentation method to arbitrarily shaped planar structures including the effect of lumped circuit... more
A compact relation is developed based on the indefinite impedance matrix. The proposed technique generalizes the application of the segmentation method to arbitrarily shaped planar structures including the effect of lumped circuit components. The components are accounted for by modifying the previously used terminal relations in the development of the segmentation method. The proposed algorithm targets power integrity (PI) applications in printed circuits and integrated circuit packages. By direct computation of distributed circuit parameters of planar power delivery networks (PDN) including discrete components, the need for a second phase circuit simulation is eliminated. An application of the proposed method is demonstrated on a practical circuit and the results are validated in comparison to a numerical electromagnetic (EM) simulator.
Research Interests:
A Newton-Raphson (N-R) based method is developed for performance evaluation of power delivery networks (PDN) with arbitrarily shaped parallel-plate power/ground plane pairs. The proposed method allows for PI assessment in a few iteration... more
A Newton-Raphson (N-R) based method is developed for performance evaluation of power delivery networks (PDN) with arbitrarily shaped parallel-plate power/ground plane pairs. The proposed method allows for PI assessment in a few iteration steps while providing significant computational efficiency compared to alternative methods. The proposed method is tested on a practical example and the results are observed in good agreement with those obtained from a numerical electromagnetic (EM) simulator.
Research Interests:
A new model is proposed to explain the effectiveness of decoupling capacitors in relation to their proximity to device power pins. The proposed approach applies to power delivery networks (PDN) designed as parallel-plate power ground... more
A new model is proposed to explain the effectiveness of decoupling capacitors in relation to their proximity to device power pins. The proposed approach applies to power delivery networks (PDN) designed as parallel-plate power ground plane pairs. The effectiveness of capacitors is explained through the device pin input impedance which can be expressed as a function of spatial coordinates. The proposed method conforms well to general observations and is validated by numerical examples.
Research Interests:
A novel approach for evaluating the efficiency of decoupling capacitors is proposed for power delivery networks (PDN). The method relies on the spacing measured from a device reference point to the nearest capacitor and can be used as a... more
A novel approach for evaluating the efficiency of decoupling capacitors is proposed for power delivery networks (PDN). The method relies on the spacing measured from a device reference point to the nearest capacitor and can be used as a guide for the placement and optimization of local decoupling capacitors on chip, package or PCB medium. Simple relations are developed including the mutual interaction between components and their accuracy is validated by a case study.
Research Interests:
The segmentation method used for the analysis of arbitrarily shaped planar structures is extended to a more general form to account for capacitive loading between parallel plates. In power integrity (PI) analysis of power delivery... more
The segmentation method used for the analysis of arbitrarily shaped planar structures is extended to a more general form to account for capacitive loading between parallel plates. In power integrity (PI) analysis of power delivery networks (PDN), the capacitive loading represents decoupling capacitors between power and ground planes. The algorithm is geared to the analysis of PDNs for performance evaluation, selection and placement of decoupling capacitors. For linear circuits, the proposed integrated algorithm eliminates the commonly used two-step approach. In the case of nonlinear loads, the algorithm helps to reduce the size of modified admittance matrix (MNA) and relaxes the burden of following circuit simulation. The proposed method is validated in comparison to a numerical electromagnetic (EM) simulator.
Research Interests:
A method is proposed to calculate the effectiveness of a decoupling capacitor in the presence of other capacitors. The previously developed scalar expressions for calculating the effective radius of a capacitor in isolation are extended... more
A method is proposed to calculate the effectiveness of a decoupling capacitor in the presence of other capacitors. The previously developed scalar expressions for calculating the effective radius of a capacitor in isolation are extended to matrix relations which account for mutual coupling. In the same vein, the scalar operations are substituted by their matrix counterparts including the calculation of derivatives using matrix calculus techniques which are required for the iterative solution of the problem. The proposed method is tested on a sample case and the results are observed to compare favorably against those from a numerical electromagnetic (EM) simulator.
Research Interests:
Gauss-Newton (G-N) based method is proposed for optimal placement and performance evaluation of local decoupling capacitors on resonant parallel-plates. Multiple power pins are used as a leverage for simultaneous placement optimization of... more
Gauss-Newton (G-N) based method is proposed for optimal placement and performance evaluation of local decoupling capacitors on resonant parallel-plates. Multiple power pins are used as a leverage for simultaneous placement optimization of multiple capacitors by utilizing matrix calculus methods. The algorithm converges in a few iterations, which is a big improvement against the competing evolutionary methods. The proposed method is tested on a sample case and the results are observed to be valid across a practically wide frequency range.
A new method is developed to assess the effectiveness of local decoupling capacitors on parallel-plate power and ground conductors. The proposed method calculates the loop-inductance of multiple capacitors including their mutual... more
A new method is developed to assess the effectiveness of local decoupling capacitors on parallel-plate power and ground conductors. The proposed method calculates the loop-inductance of multiple capacitors including their mutual interactions and the effect of power and ground vias. The underlying theory is based on computing the driving point impedance of a device power pin which serves as a reference in the evaluation of capacitor's effectiveness. The accuracy of the proposed method is validated by comparing the results to those from a full-wave electromagnetic simulation.
A novel pin impedance-based figure of merit with mutual coupling (PMC-FOM) is proposed for effectiveness assessment of a decoupling capacitor. The algorithm is based on the relative location of the capacitor on parallel plates and takes... more
A novel pin impedance-based figure of merit with mutual coupling (PMC-FOM) is proposed for effectiveness assessment of a decoupling capacitor. The algorithm is based on the relative location of the capacitor on parallel plates and takes into account mutual coupling by extending the existing scalar expressions to matrix relations. New analytical relations are developed for the calculation of derivatives as required for the iterative solution of the problem. The relations for resonant parallel plates of regular shapes are extended to the practical case of polygonal shapes. It is demonstrated that a capacitor’s effective zone can hardly be delimited with a simple circle when mutual interaction with other capacitors is considered. In fact, the presence of other capacitors deforms the circular zone to an irregular contour. The proposed method is analyzed with several benchmark examples and the results are validated for efficiency and accuracy by comparing with alternate methods including a commercial electromagnetic (EM) simulator.
Research Interests:
Crossing strip junctions form an important discontinuity problem in differential signaling an pose a major challenge for signal integrity modeling throughout an analysis in high-speed designs. An analytical framework is proposed to... more
Crossing strip junctions form an important discontinuity problem in differential signaling an pose a major challenge for signal integrity modeling throughout an analysis in high-speed designs. An analytical framework is proposed to characterize differential transmission lines including the effect of crossing strip junctions for broadband circuit analysis. A new analytical model is proposed to include the finite thickness in the existing models for characterization of asymmetric striplines. The proposed modular representation of the differential line segments with discontinuity effects allows for an entire high-speed transmission channel with crossing lines to be modeled in a cascaded fashion for efficient signal integrity analysis.
Research Interests:
A multiobjective evolutionary method is proposed for the optimization of surface mount device (SMD) multilayer ceramic chip (MLCC) capacitors used for decoupling on printed circuit boards (PCBs) with resonant power–ground plane pairs. The... more
A multiobjective evolutionary method is proposed for the optimization of surface mount device (SMD) multilayer ceramic chip (MLCC) capacitors used for decoupling on printed circuit boards (PCBs) with resonant power–ground plane pairs. The proposed approach provides options for designers to meet power integrity specifications by employing uniform-valued capacitors that help to reduce the bill-of-material (BOM) cost and mitigate the part procurement risk. It is also shown that uniform MLCC capacitors with variable distance from power pins can have a similar decoupling effect to an assortment of capacitors. By simultaneously optimizing the pin-capacitor distance and value, the proposed method is shown to allow for the allocation of fewer decoupling capacitors under the ball-grid-array (BGA) pin field of an integrated circuit (IC) device.
With rapidly increasing switching speeds and surge current requirements, placement of local decoupling capacitors is becoming critically important in high-speed low-power designs. In this paper, utilizing the driving-point impedance... more
With rapidly increasing switching speeds and surge current requirements, placement of local decoupling capacitors is becoming critically important in high-speed low-power designs. In this paper, utilizing the driving-point impedance (viewed from the device pin) as a metric, a new method is presented for the placement of decoupling capacitors in parallel-plate power ground pairs of high-speed circuits. In the proposed approach, instead of using the traditional trial-and-error method to identify an appropriate placement distance, the process is formulated in the form of a transcendental function. The resulting function is solved using Newton–Raphson (N-R) iterations to give a direct solution for the distance. Also, an analytical representation based on Hankel functions for the driving point impedance and its derivatives is developed to speed up the N-R iterations. The proposed method is validated by comparing the results with the full-wave electromagnetic simulations.
Research Interests:
A semi-analytical method is proposed to evaluate the effectiveness of a decoupling capacitor on resonant power and ground planes. New expressions are developed relating the pin impedance to relative placement of a capacitor with... more
A semi-analytical method is proposed to evaluate the effectiveness of a decoupling capacitor on resonant power and ground planes. New expressions are developed relating the pin impedance to relative placement of a capacitor with associated angular and distance parameters. To speed up the solution of resulting transcendental equations, a 2-D iterative technique is proposed, which yields the effective distance as well as the angle between a decoupling capacitor and a power pin. The partial derivatives of the corresponding Jacobian matrix are analytically derived. Numerical examples are presented to demonstrate the validity of the proposed method, which also investigates the effect of plane edges on pin impedance.
Research Interests:
A genetic algorithm (GA)-based method is proposed for simultaneous optimization of decoupling capacitors assigned to multiple pins of a ball-grid array (BGA) package on a printed circuit board. A noise susceptibility parameter is... more
A genetic algorithm (GA)-based method is proposed for simultaneous optimization of decoupling capacitors assigned to multiple pins of a ball-grid array (BGA) package on a printed circuit board. A noise susceptibility parameter is introduced as the basis of a new set of GA fitness functions. Performance of several fitness functions is comparatively tested and discussed in case studies. The accuracy of the developed expressions is tested against full-wave electromagnetic simulation results. The proposed method is particularly useful for predicting the number and placement of decoupling capacitors under the BGA area of integrated circuit devices in early design stages and serves as a complement to rigorous algorithms that are used in the final phase of the design.
Research Interests:
In this paper, a novel approach is presented for an integrated analysis of power distribution networks, including dc–dc converters, power transmission lines (PTLs), and multiple loads. The effect of power interconnects is investigated on... more
In this paper, a novel approach is presented for an integrated analysis of power distribution networks, including dc–dc converters, power transmission lines (PTLs), and multiple loads. The effect of power interconnects is investigated on the dynamic characteristics of a pulsewidth-modulated buck converter. A closed-form relation is developed for control-to-output transfer function including the power interconnects as a transmission line model. The effect of PTLs is demonstrated on converter’s open-loop transfer function and its stability. For analysis of distributed power loads on printed circuit board PTLs, a model is developed based on cascaded matrix representation of interconnects. The model is successfully tested against planar electromagnetic simulation results.
Research Interests:
The input-to-output transfer function of a buck converter is investigated including power transmission line parameters, accounting for printed circuit board (PCB) parasitics. A closed-form relation is developed for the transfer function... more
The input-to-output transfer function of a buck converter is investigated including power transmission line parameters, accounting for printed circuit board (PCB) parasitics. A closed-form relation is developed for the transfer function to be used in small-signal analysis. Also, the effect of power transmission lines is demonstrated on control-to-output transfer function of the converter.
Research Interests:
In this paper, a new formulation is provided to model the noise coupling between adjacent planes in a multilayer stackup. A model is developed to show that the planar coupling depends heavily on the wave impedance of each power plane.... more
In this paper, a new formulation is provided to model the noise coupling between adjacent planes in a multilayer stackup. A model is developed to show that the planar coupling depends heavily on the wave impedance of each power plane. Also a rigorous investigation of planar noise coupling with respect to the separation distance between the planes and use of decoupling capacitors is presented. The validity of the developed model is successfully tested on sample structures.
In this paper, the ac small-signal relations of commonly used DC-DC controllers such as buck, boost and buck-boost are extended to include distributed PCB effects. The critical parameters of these controllers including input-to-output,... more
In this paper, the ac small-signal relations of commonly used DC-DC controllers such as buck, boost and buck-boost are extended to include distributed PCB effects. The critical parameters of these controllers including input-to-output, control-to-output transfer functions and the output impedance impacting power and EMC designs are derived. Using the newly developed broadband model, the effect of PCB parasitics are investigated and compared to the conventional relations.
Research Interests:
The design parameters of a buck converter are investigated based on ac small-signal design parameters such as open-loop, input-to-output and control-to-output transfer functions including distributed circuit parameters that account for... more
The design parameters of a buck converter are investigated based on ac small-signal design parameters such as open-loop, input-to-output and control-to-output transfer functions including distributed circuit parameters that account for PCB parasitics. It is demonstrated that the PCB effects neglected in a 2nd order model could affect the design parameters such as selection of switching frequency. The relations developed in this work are validated in the power design of an idustrial circuit and compared to the conventional 2nd order models.
Research Interests: Engineering and IEEE
A multi-port constrained optimization methodology is presented for optimal placement of decoupling capacitors in power distribution networks (PDN) of Printed Circuit Boards (PCB). The proposed method is based on Barrier Methods and can... more
A multi-port constrained optimization methodology is presented for optimal placement of decoupling capacitors in power distribution networks (PDN) of Printed Circuit Boards (PCB). The proposed method is based on Barrier Methods and can simultaneously handle multiple ball grid array (BGA) device and capacitor ports on practical power/ground plane pairs of polygonal shapes without restriction in the problem geometry. Semi-analytical expressions are developed for the magnitude of device port impedance which is set as the objective function. The placement optimization problem including constraints of planar boundaries and impedance specifications is cast into a matrix expression that meets Karush-Kuhn Tucker (KKT) conditions and solved through Newton-Raphson (N-R) iterations. The convergence of iterations is ensured by guaranteeing the positive definiteness of the system matrix through the Levenberg-Marquardt algorithm. Mutual coupling among multiple ports and discrete components of the problem domain is accounted for via matrix calculus techniques applied to the partial derivatives of optimization variables. The derivatives are evaluated accurately exploiting the semi-analytical relations developed for the distributed planar impedance. The proposed method is tested with several examples and the results are observed to be in good agreement with those obtained from a numerical electromagnetic (EM) simulator while yielding significant speed-up.
— Artificial neural networks (ANN) have gained attention as fast and flexible vehicles to microwave modeling and design. This paper reviews a recent advance of neural network modeling, i.e., state-space dynamic neural network (SSDNN) for... more
— Artificial neural networks (ANN) have gained attention as fast and flexible vehicles to microwave modeling and design. This paper reviews a recent advance of neural network modeling, i.e., state-space dynamic neural network (SSDNN) for transient behavioral modeling of high-speed nonlinear circuits. The SSDNN model can be directly trained from the input and output waveforms without relying on the circuit internal details. A training algorithm exploiting adjoint sensitivities is summarized for training the model in an efficient manner. An example of the SSDNN technique for IC buffer modeling and its use with transmission line elements in high-speed interconnect design are included. DOI: 10.2529/PIERS060907175229 With the continuous increase of signal speed and frequency, signal integrity (SI) in VLSI pack-ages becomes more and more prominent. Fast and accurate representations of the nonlinear analog behaviors of driver/receiver buffers are the key to the success of SI-based design o...
Research Interests:
A constrained optimization algorithm is proposed for the optimal placement of decoupling capacitors on power delivery networks (PDN) of high-speed digital circuits. The algorithm is based on barrier methods and calls for the first and... more
A constrained optimization algorithm is proposed for the optimal placement of decoupling capacitors on power delivery networks (PDN) of high-speed digital circuits. The algorithm is based on barrier methods and calls for the first and second order partial derivatives of optimization variables for gradient search. In the analysis, the PDN is modeled as a resonant planar circuit. In the calculation of derivatives, mutual coupling among multiple ports and discrete components of the problem domain is accounted for with matrix calculus techniques. An analytical representation of the plane impedance is utilized for accurate calculation of the derivatives. The proposed method is tested on a practical example and the results are observed in good agreement with those obtained from a numerical electromagnetic (EM) simulator.
A Gauss-Newton (G-N) based method is developed for the analysis of power delivery networks (PDN) with arbitrarily shaped parallel-plate power/ground plane pairs. The proposed method allows for power integrity (PI) assessment in a few... more
A Gauss-Newton (G-N) based method is developed for the analysis of power delivery networks (PDN) with arbitrarily shaped parallel-plate power/ground plane pairs. The proposed method allows for power integrity (PI) assessment in a few iteration steps, providing significant speed-up in comparison to alternative methods. The proposed method is tested on a practical example which includes a 16-pin ball-grid array (BGA) device and the results are observed in good agreement with those obtained from a numerical electromagnetic (EM) simulator.
Analytical models of high-speed interconnects are becoming increasingly important due to the large number and repetitive nature of signal integrity simulations. In this paper, closed-form relations are developed to calculate the... more
Analytical models of high-speed interconnects are becoming increasingly important due to the large number and repetitive nature of signal integrity simulations. In this paper, closed-form relations are developed to calculate the characteristic impedance of differential traces routed on asymmetrical dual stripline layers. The solution is based on Schwartz-Christoffel transformation in combination with the partial capacitance concept. Numerical examples demonstrating the accuracy of the proposed method have been presented.
Research Interests:
A novel pin impedance based figure of merit including mutual coupling (PMC-FOM) is proposed for effectiveness assessment of a decoupling capacitor. The algorithm is based on the relative location of the capacitor on parallel plates and... more
A novel pin impedance based figure of merit including
mutual coupling (PMC-FOM) is proposed for effectiveness
assessment of a decoupling capacitor. The algorithm is based
on the relative location of the capacitor on parallel plates and
takes into account mutual coupling by extending the existing
scalar expressions to matrix relations. New analytical relations
are developed for the calculation of derivatives as required for
the iterative solution of the problem. The relations for resonant
parallel plates of regular shapes are extended to the practical
case of polygonal shapes. It is demonstrated that a capacitor’s
effective zone can hardly be delimited with a simple circle when
mutual interaction with other capacitors is considered. In fact,
the presence of other capacitors deforms the circular zone to an
irregular contour. The proposed method is analyzed with several
benchmark examples and the results are validated for efficiency
and accuracy by comparing with alternate methods including a
commercial electromagnetic (EM) simulator.
mutual coupling (PMC-FOM) is proposed for effectiveness
assessment of a decoupling capacitor. The algorithm is based
on the relative location of the capacitor on parallel plates and
takes into account mutual coupling by extending the existing
scalar expressions to matrix relations. New analytical relations
are developed for the calculation of derivatives as required for
the iterative solution of the problem. The relations for resonant
parallel plates of regular shapes are extended to the practical
case of polygonal shapes. It is demonstrated that a capacitor’s
effective zone can hardly be delimited with a simple circle when
mutual interaction with other capacitors is considered. In fact,
the presence of other capacitors deforms the circular zone to an
irregular contour. The proposed method is analyzed with several
benchmark examples and the results are validated for efficiency
and accuracy by comparing with alternate methods including a
commercial electromagnetic (EM) simulator.
Research Interests:
A genetic algorithm (GA)-based method is proposed for simultaneous optimization of decoupling capacitors assigned to multiple pins of a ball-grid array (BGA) package on a printed circuit board. A noise susceptibility parameter is... more
A genetic algorithm (GA)-based method is proposed for simultaneous optimization of decoupling capacitors assigned to multiple pins of a ball-grid array (BGA) package on a printed circuit board. A noise susceptibility parameter is introduced as the basis of a new set of GA fitness functions. Performance of several fitness functions is comparatively tested and discussed in case studies. The accuracy of the developed expressions is tested against full-wave electromagnetic simulation results. The proposed method is particularly useful for predicting the number and placement of decoupling capacitors under the BGA area of integrated circuit devices in early design stages and serves as a complement to rigorous algorithms that are used in the final phase of the design.
With rapidly increasing switching speeds and surge current requirements, placement of local decoupling capacitors is becoming critically important in high-speed low-power designs. In this paper, utilizing the driving-point impedance... more
With rapidly increasing switching speeds and surge current requirements, placement of local decoupling capacitors is becoming critically important in high-speed low-power designs. In this paper, utilizing the driving-point impedance (viewed from the device pin) as a metric, a new method is presented for the placement of decoupling capacitors in parallel-plate power ground pairs of high-speed circuits. In the proposed approach, instead of using the traditional trial-and-error method to identify an appropriate placement distance, the process is formulated in the form of a transcendental function. The resulting function is solved using Newton-Raphson (N-R) iterations to give a direct solution for the distance. Also, an analytical representation based on Hankel functions for the driving point impedance and its derivatives is developed to speed up the N-R iterations. The proposed method is validated by comparing the results with the full-wave electromagnetic simulations.
In this paper, a novel approach is presented for an integrated analysis of power distribution networks, including dc-dc converters, power transmission lines (PTLs), and multiple loads. The effect of power interconnects is investigated on... more
In this paper, a novel approach is presented for an integrated analysis of power distribution networks, including dc-dc converters, power transmission lines (PTLs), and multiple loads. The effect of power interconnects is investigated on the dynamic characteristics of a pulsewidth-modulated buck converter. A closed-form relation is developed for control-to-output transfer function including the power interconnects as a transmission line model. The effect of PTLs is demonstrated on converter's open-loop transfer function and its stability. For analysis of distributed power loads on printed circuit board PTLs, a model is developed based on cascaded matrix representation of interconnects. The model is successfully tested against planar electromagnetic simulation results.
Crossing strip junctions form an important discontinuity problem in differential signaling an pose a major challenge for signal integrity modeling throughout an analysis in high-speed designs. An analytical framework is proposed to... more
Crossing strip junctions form an important discontinuity problem in differential signaling an pose a major challenge for signal integrity modeling throughout an analysis in high-speed designs. An analytical framework is proposed to characterize differential transmission lines including the effect of crossing strip junctions for broadband circuit analysis. A new analytical model is proposed to include the finite thickness in the existing models for characterization of asymmetric striplines. The proposed modular representation of the differential line segments with discontinuity effects allows for an entire high-speed transmission channel with crossing lines to be modeled in a cascaded fashion for efficient signal integrity analysis.
A semi-analytical method is proposed to evaluate the effectiveness of a decoupling capacitor on resonant power and ground planes. New expressions are developed relating the pin impedance to relative placement of a capacitor with... more
A semi-analytical method is proposed to evaluate the effectiveness of a decoupling capacitor on resonant power and ground planes. New expressions are developed relating the pin impedance to relative placement of a capacitor with associated angular and distance parameters. To speed up the solution of resulting transcendental equations, a 2-D iterative technique is proposed, which yields the effective distance as well as the angle between a decoupling capacitor and a power pin. The partial derivatives of the corresponding Jacobian matrix are analytically derived. Numerical examples are presented to demonstrate the validity of the proposed method, which also investigates the effect of plane edges on pin impedance.
A multiobjective evolutionary method is proposed for the optimization of surface mount device (SMD) multilayer ceramic chip (MLCC) capacitors used for decoupling on printed circuit boards (PCBs) with resonant power-ground plane pairs. The... more
A multiobjective evolutionary method is proposed for the optimization of surface mount device (SMD) multilayer ceramic chip (MLCC) capacitors used for decoupling on printed circuit boards (PCBs) with resonant power-ground plane pairs. The proposed approach provides options for designers to meet power integrity specifications by employing uniform-valued capacitors that help to reduce the bill-of-material (BOM) cost and mitigate the part procurement risk. It is also shown that uniform MLCC capacitors with variable distance from power pins can have a similar decoupling effect to an assortment of capacitors. By simultaneously optimizing the pin-capacitor distance and value, the proposed method is shown to allow for the allocation of fewer decoupling capacitors under the ball-grid-array (BGA) pin field of an integrated circuit (IC) device.
ABSTRACT Due to the rapid surge in operating frequencies and complexity of modern VLSI designs, fast and accurate EMC/EMI analysis is becoming mandatory. This paper presents a closed-form SPICE macromodel for fast transient analysis of... more
ABSTRACT Due to the rapid surge in operating frequencies and complexity of modern VLSI designs, fast and accurate EMC/EMI analysis is becoming mandatory. This paper presents a closed-form SPICE macromodel for fast transient analysis of lossy multiconductor transmission lines in the presence of incident electromagnetic fields. In the proposed algorithm, the equivalent sources due to incident fields are formulated analytically in the time-domain, based on the information of line and incident field parameters. The resulting time-domain macromodel is in the form of ordinary differential equations and can be easily included in existing analog circuit simulators such as SPICE. The proposed algorithm, while guaranteeing the stability of the transient simulation by employing passive macromodels, provides significant speed-up for high-speed interconnect networks, especially with large delay and low losses.
ABSTRACT With the continually increasing frequencies and densities of modern VLSI designs, fast and accurate EMC/EMI analysis is becoming mandatory. This paper presents a closed-form SPICE macromodel for fast transient analysis of lossy... more
ABSTRACT With the continually increasing frequencies and densities of modern VLSI designs, fast and accurate EMC/EMI analysis is becoming mandatory. This paper presents a closed-form SPICE macromodel for fast transient analysis of lossy multiconductor transmission lines with frequency-dependent parameters, in the presence of incident electromagnetic fields. In the proposed algorithm, the equivalent sources due to incident fields are formulated analytically in the time-domain, based on the information of line and incident field parameters. The resulting time-domain macromodel is in the form of ordinary differential equations and can be easily included in existing analog circuit simulators such as SPICE. The proposed algorithm, while guaranteeing the stability of the transient simulation by employing passive macromodels, provides significant speed-up for high-speed interconnect networks, especially with large delay and low losses.