TW201018068A - Synchronous rectifier DC/DC converters using a controlled-coupling sense winding - Google Patents

Abstract

A synchronous rectifier DC/DC converter is provided. The synchronous rectifier DC/DC converter includes a power transformer, a first diode, a first MOSFET, and a first controller. The power transformer includes a core, a primary winding, a secondary winding, and a sense winding. The primary winding is wrapped around the core and receives an input voltage of the synchronous rectifier DC/DC converter. The secondary winding is wrapped around the core and provides the energy of an output current of the synchronous rectifier DC/DC converter. The sense winding is wrapped around the core and provides a sense signal. The first MOSFET is coupled in parallel with the first diode. The first controller is coupled to the sense winding and the first MOSFET for turning on and turning off the first MOSFET according to the sense signal.

Description

201018068 / ioc/n IX. Description of the Invention: [Technical Field] The present invention relates to a synchronous rectifier dc/dc converter, and more particularly to a control rectifier coil Synchronous rectified DC-to-DC transformer with controlled-coupling sense winding. [Prior Art] In computer equipment and other digital electronic products, AC-DC switching-mode power supplies (SMPS) are used, and most of their internal transformers use a flyback transformer ( Flyback converter) or a forward converter. These transformers typically use a PN junction diode or a Schottky diode as the output rectifier. Due to the forward voltage difference vf of the diode rectifier, the voltage supplied to the power supply ranges from 0.5V to IV'. Therefore, the input power loss is from the forward voltage difference Vf', and the power loss percentage is about 4%. ~1〇%. Metal The power-oxide-semiconduetoi field-effect transistor (MOSFET) is a majority carrier component. In recent years, due to the development of the gold-oxygen half-field effect transistor technology, the on-resistance Rds resistance of the power metal oxide half-field effect transistor can be less than 1 〇 milliohm. Therefore, the use of power MOS field-effect transistors in place of synchronous rectifiers, PN junction diodes or Schottky transistors to improve the efficiency of SMPS has become more and more important. 1 is a schematic diagram showing the use of a pair of self-driven doc/n 201018068 self-driven synchronous rectifiers for a conventional forward transformer. This synchronous rectified forward converter uses two synchronous rectification MOS field-effect transistors, Q2 and two rectifying diodes, namely a forward diode D1 and a • free flywheel (free_wheeling) Dimorph D2. The power MOS half field &amplifier Q1 and Q2 are respectively connected in anti-parallel to the diodes m and D2. Ideally, the opening and closing times of Q1 and Q2 will be synchronized with the conduction time of the di^D2 parameter, respectively. The power transformer Tr1 has a main coil ni and a secondary coil n2, the Q1 _ pole is connected to the high side of the secondary coil ^, and the gate of Q2 is connected to the low side of the secondary coil n2 (low side) ). Before, after, and under the power supply, the output current _ ^ ^ paves D2 and the output inductor L0. When Qp is turned on, the coil nl of the power transformer state Tr1 is supplied with the wheel-in voltage, and the voltage Vn2 is induced. The intensity of the coil is n2 Λ Figure 2 is the voltage between the graphs, and the _ is the gold oxide. Half awkward; and: source one ^

The electric power between the poles is repeated, Vgsl is the golden oxygen f曰曰QP has the drain and the source ink, and vgs2 is the golden half-field effect and the source. The main power switch Qp is turned on at time ^, and the power between the sources is Τ2. From the time point Τ 2 to 13, during. ', 1 and off at the point in time will rise to approximately the voltage between the two and two sources of Vin reset circuit reset (t). The tensor Tr will be RCD () at the time point, the transformer Tr will be 6 201018068 ioc / n set, and the Vds voltage will drop to the value of Vin. Finally, at the time point of T4, Qp will be turned on again to start another new cycle. Since the gate of Q1 is connected to Vn2, when Vn2 is positive, the conduction time of Q1 is synchronized with the conduction time of qp. On the other hand, since the gate of Q2 is connected to the low level of the coil n2, its conduction time can only be between the time points T2 and T3 or the transformer Tr1 #reset time. During the time point T3 to T4, the voltage Vn2 across the coil n2 is 〇, and the voltage Vgs between the gate and the source of the MOSFET half-effect transistor Q2 is 〇, so Q2 is in a closed state. In addition, since the freewheel current only flows through the transistor D2, a large amount of conduction loss is caused. 不 The free conduction time of the free-wheeling synehfQ_s rectifier is a major disadvantage of the self-driven synchronous rectifier. Especially in the case of high input voltage and high load, the conduction time of Qp is even shorter, and the reset time will be correspondingly shortened, thus causing the utilization of freewheel rectifier q2 to decrease. In order to solve the problem of incomplete conduction time in self-driven synchronous rectifiers, many synchronous rectification control circuits using a predictive turn-off scheme have been proposed commercially, and FIG. 3 shows a conventional predictive synchronization. Rectifier control circuit. As shown in Fig. 4, the prediction timing of the predictive synchronous rectification controller 31 is based on the Vn2 waveform. Q1 is turned on with the rising edge of γη2 (rising e(jge), but there is a short delay time Tdell, and short time Tdel2 before Qp is turned off, Q1 will be turned off' where Tdell time and Tdel2 time are about the same size 100n seconds and 200n seconds. In other words, according to the waveform of the previous 7 a〇c/n 201018068 cycle Vn2, the conduction time of the new cycle qi can be obtained.

Toff(n+l) - Tonl(n+l) = Toffp(8)-Tonp(8)-Tdell ~

Tdel2 In addition, Q2 will be turned on after a short delay time TdeU as Qp is turned off. Before the time Tdel2 before Qp is turned on, it is the time when Q2 is turned off. Therefore, the above method has reached the prediction method. In other words, as shown in Fig. 4, the conduction time of the new period Q2 can be obtained according to the waveform of the previous period Vn2. ’

Toff2(n+l) - Ton2(n+l) = Tonp(n+l) - Toffp(n) Tdell - Tdel2 The above predictive synchronous rectifier control method can be effectively used under the fixed switching frequency of the rectifier. However, in the case of ^, the 'predictive method will cause a breakdown condition (sh〇〇tthiOu & condition) causing serious damage to the component. The breakdown condition described above is the short circuit condition that occurs when the main power switch Qp is turned on before the freewheel rectifier Q2 (4) is closed. However, it is not conducive to the Qp accident of the prediction method. For the transformer to operate at a variable switching frequency, the spectrum-type transformer is operated by a spread spectrum (spread). -spectmm) at the switching frequency. In addition, the power saving mode of the ton-type _ _ light load condition is balanced: cycle, which also creates a county wear situation. The stomach-two-switching is shown as the relevant signal waveform when the breakdown occurs. Where Vgp is the electrical and period (n+1) time between the gate and the source of the main power switch Qp, the forward type transformer operates at a fixed frequency and the week 8 201018068 / t/o*r«.wi.'J. 〇C/n (n+2) ' Qp turns on the pulse faster than the previous cycle. As shown in Figure $, the time point of the turn-on is Τ5, which is earlier than the time point when Q2 is turned off. When Q2 is turned on, Vn2 is short-circuited to ground via Q2. During the time Τ5 Τ6, a large amount of current flows through Q2 and Dl. To make matters worse, when Vn2 is short-circuited to ground by Q2, the voltage of Vn2 may be only tens of millivolts (milli-v〇lts), and during the breakdown, the waveform of Vn2 is a noise-filled waveform' These factors will make it difficult for the control circuit to sense the short circuit. ❹ / As shown in Fig. 5, during the breakdown condition, the large amount of current flowing through Q2 is limited only by the leakage inductance of the party coil n2. The large breakdown current can easily cause serious damage to the power MOS half-effect transistor. Λ In order to prevent the breakdown current from causing damage to the synchronous rectifier, the time point at which Qp is turned on must be sensed. Because you know the time point after Qp is turned on, you can quickly turn off Q2' to avoid the breakdown. As shown in Fig. 6, an independent pulse transformer is a frequently used method for solving breakdown current damage. The independent pulse transformer Tr2 is used to transmit the turn-on time of Qp to the synchronous rectification control circuits 610 and 620. The pulse transformer Tr2 is physically separated from the power transformer Tr1, and the pulse transformer Tr2 can transmit a clean and reliable signal Vpt to the synchronous rectification controller 620, which is the opening and closing of the Qp. The controller 620 can turn off Q2 according to any of the following conditions; (a) the q2 conduction time predicted by the pre-switching period; and (8) the QP turn-on time, that is, the rising edge of Vpt. For the following description, please refer to FIG. 6 and FIG. 7 in combination. The synchronous rectification controller can be 9 201018068 7 _ · one ------ioc/n to monitor the opening condition of Qp by the rising edge of VPt, and the Qp opening time p is earlier than Q2 closing time T6, so it sucks m There will be - a large amount of breakdown current. However, when the synchronous rectification controller senses the rising edge and the edge of Vpt# at the time point, the synchronous rectification controller (4) will immediately turn Q2 off. Therefore, at time T6, Q2 is off. Therefore, at time Ί7, the breakdown current is reduced to Q. Compared with the peak value of Fig. 7, the peak value of the breakdown current of Fig. 7 is much lower. This is (4) When QP is turned on, the Q2 is turned off immediately, and the breakdown current is reduced. Although the switching signal of Qp is transmitted by the pulse transformer, the problem of breakdown current can be effectively solved. However, since the pulse transformer Tr2 is an additional transformer' equals one more circuit component, and the pulse transformer must also follow the International Standards for Safety and Safety. Therefore, the method of using pulse wave to transform enthalpy has the problem of excessive volume and high cost. The above-mentioned international safety standards organizations such as Underwriters Laboratories (UL), Canadian Standards Association, and the International Electrotechnical Commission (IEC) ° [invention] Therefore, the present invention provides a synchronization Synchronous rectifier dc/dc converter, which is characterized by a simple control light-connected induction coil in its power transformer (p〇wer transf〇rmer) c〇ntr〇llecj_C0Upiing sense winding) ° Control coupling the induction coil can provide a reliable and noise-free switching signal to limit the breakdown (shoot-though 201018068 μ / vo^tiwi. Joc/n condition) Current spike. The invention provides a synchronous rectifier dc/dc converter comprising a power converter, a first pole body, a first gold gas half field effect transistor and a first controller. The complex medium power transformer includes a core, a primary winding, a secondary winding, and a sense wining. The main coil is wound around the core and is used to receive the input voltage of the synchronous rectified DC to DC transformer ❹. In addition, the secondary coil is also wound around the core and is used to provide energy for the output current of the synchronous rectified DC to DC transformer. The induction coil is wound around the core and provides an inductive signal. The first diode is coupled to the secondary coil for rectifying the output current, and the first metal oxide half field effect transistor is coupled to the first diode. The first controller is coupled to the induction coil and the first gold oxide half field effect transistor, and opens and closes the first metal oxide half field effect transistor according to the sensing signal. In an embodiment of the invention, the primary coil is interposed between the secondary coil and the inductive coil. The power transformer can have two different coil configurations. Chapter © One configuration is such that the primary coil is wound around the secondary coil and the induction coil is wound around the primary coil. In another configuration, the primary coil is wound around the induction coil and the secondary coil is wound around the primary coil. In another embodiment of the invention, the induction coil is interposed between the primary coil and the secondary coil. The power transformer can have two different coil configurations. In the first configuration, the induction coil is wound around the main coil, and the secondary coil is wound around the induction coil. In addition, the structure is such that the induction coil is wound around the secondary coil and the primary coil is wound around the induction coil. 11 20101806Soc/n In another embodiment of the invention, the falling edge of the first control number turns on the first gold-oxygen half field effect transistor. In another embodiment of the invention, the time at which the first controller turns on the first gold oxide half field effect transistor is earlier than the first time point and the second time point. The first time point is determined by the edge of the domain response signal - the second time _ is determined according to the rising edge of the second cycle of the loyalty, and the first cycle is earlier than the second cycle

In the present invention, the step-by-step rectification DC-to-DC converter is a forward transformer 'and includes a second diode, a second gold gas field effect transistor, and a second controller. The second diode is disposed on the secondary coil and the first diode to rectify the output current. The second gold-oxygen half-field effect transistor is axially connected to the second diode body', and the second controller is connected to the induction coil and the second gold-oxygen half field effect transistor, and the first signal is turned on or off according to the sensing signal Two gold oxygen half field effect transistor. In another embodiment of the present invention, the second controller turns on the second oxy-half half according to the rising edge of the first period of the sensing signal, and the second controller turns off the second field-effect transistor. The time point is estimated by the falling edge of the second period of the sensing signal, and the previous period is earlier than the first period. In order to make the above features and advantages of the present invention more obvious, the following preferred embodiments are preferred. Referring to the drawings, a detailed description will be given below. [Embodiment] Please refer to FIG. 8. FIG. 8 is a schematic diagram of a synchronous rectification direct-turn DC-to-DC voltage transformation according to an embodiment of the present invention. The transmitter is ^· 12 wc/n 201018068 Forward-type transformer, including power-changing gold-oxygen half-field electric crystallographer ί = pole body 〇 1 and 1 (10) and other components. Among them, 10A, Figure 11A or Figure 12A two-rate transformer The 800 can be designed as an open type of ', and + port' and the power transformer 800 includes - line: 'The ship is to be coiled, the secondary coil 112 and the induction coil η3. Mainly in: the core is used to receive Synchronous rectification DC to DC transformer

Itsvin. The secondary coil is entangled in the core and is used to provide the same (f), the flow of the fourth (four) flow, and the induction of the card, the induction signal Vn3, and the induction signal Vn3 are voltage signals. In FIG. 8, a pole body D1 is coupled to the secondary coil ^ and the diode for rectifying the output current lGut. The gold-oxygen half-field effect transistor is connected in parallel to the -pole D1°Q1 controller, which is connected to the induction coil η3 and the MOS:: transistor Q1', which is used to turn on or off the gold-oxygen half-field power according to the inductive signal Vn3 (4) Q The diode is reduced to the secondary coil to rectify the output current lout. The gold-oxygen half-field effect transistor Q2 is connected in parallel to the pole body D2°Q2 controller is coupled to the induction coil n3 and the gold-oxygen half-field power device: body Q2, which is used to turn on or off the golden oxygen half according to the induction signal Vn3.昜Discharge crystal Q2. The remaining components of the synchronous rectifier DC-to-DC converter in Fig. 8 are similar to the corresponding components in Fig. 6, and will not be described again. When the gold-oxygen half-field effect transistor Qp is turned on, the induction coil n3 generates an inductive signal Vn3, which is a better signal than the signal Vpt in FIG. FIG. 9 is a waveform diagram of the synchronous rectification DC-DC voltage regulator of FIG. 8. For the following description, please refer to FIG. 8 and FIG. 9 together, and the Q1 controller 810 in FIG. 8 13 <-*〇c/n 201018068 is in the country (a, compared to the Q1 controller 610 in FIG. 6 except Γί The signal % in t6 is replaced by the same as the sensing signal η in Fig. 8. The same as above, the controller 820 f in Fig. 8 has the same function of the Q2 controller 620 in Fig. 6, except that In response to the signal on which the gold-oxygen half-field transistor q2 is turned on, the signal Vn3 in FIG. 8 is replaced by the inductive signal Vn3 in FIG.

As shown in Fig. 9, the predicted timing of the synchronous rectification Q1 controller 810 is the timing corresponding to the sensing signal Vn3. Q1 with

Vn3 is turned on with a rising edge of the 4th cycle of the Vn3 but has a slight prediction or conduction delay (propagati〇ndelay). In addition, 卩丨 will be turned off at a preset time before the QP is turned off. The turn-off time of Q1 can be estimated from the falling edge (can) of the Vn3 waveform. In addition, the prediction time of the synchronous rectification Q2 controller 820 is also turned on according to the falling edge of the current period of Vn3 according to the inductive signal Vn3 〇 Q2, but with a slight prediction or conduction delay, and the Q2 controller 820 is The time point of closure is the earlier of the first time point and the second time point. The first time point T7 can be predicted based on the rising edge of the front-period of the inductive signal Vn3. The second time point T6 is after the rising edge of the current period of the inductive signal vn3, plus a short prediction or conduction delay. When the switch cycle of Qp remains constant, Q2 controller 820 will turn Q2 off at the predicted first time point T7. In addition, when the switching period of Qp is changed such that Qp is turned on before Q2 is turned off, in this case, Q2 controller 820 senses the rising edge of the sensing signal Vn3 and correspondingly turns off the golden oxide half field effect transistor Q2. Due to the above mechanism, the gold oxide 201018068 uuc/ri half-field effect transistor Q2 can be immediately turned off, thus preventing the damage caused by the breakdown. Ideally, even if a breakdown occurs during the time points T5 and T7, the induction coil n3 can still be supplied to the Q2 controller - a clean and reliable waveform Vn3. Therefore, as long as the induction coil n3 can provide the opening time of the main switch Qp of the mold, the Q2 controller can turn off the gold-oxygen half-effect transistor Q2 when the breakdown phenomenon occurs. Therefore, a reliable sensing signal Vn3 can keep the breakdown current surge under a safe standard. ❹ In order to make the inductive signal Vn3 of the induction coil n3 a reliable and noise-free signal, it is necessary to know the coil structure of the power transformer, the light coupling coefficient between the coils, and the breakdown of the power transformer. (primary-side circuit) interaction with a secondary-side circuit. In essence, to make the inductive signal Vn3 a reliable and noise-free signal, the relationship between the induction coil n3 and the main coil n1 can be increased, and the light relationship between the induction coil n3 and the secondary coil n2 can be reduced. . In the following description, the three different coil configurations of the power transformer 800 are mainly explained, and the different results are presented. FIG. 10A is a cross-sectional view of the core and coil of the power transformer 800. In the coil structure as shown in Fig. 10A, the position of the induction coil is inappropriate. The reason is as follows. Wherein the main coil η1 is placed in the innermost layer, the secondary coil n2 is placed in the middle, and the induction coil n3 is placed in the outermost layer. In the coil structure of the present embodiment, the coil n1 has a good coupling relationship with the coil n2, and the shielding 15 201018068 / vo'ttw j.doc/n effect effect caused by the coil n2 causes the coil nl and The coupling relationship between the induction coils n3 is poor. Figure 10B illustrates an equivalent circuit model of the power transformer 800 of Figure 10A. The main switch Qp is turned on under the breakdown condition, and the main switch Qp and the gold-oxygen half field effect transistor Q2 are both turned on. Lm is the magnetizing inductance of the power transformer 800, Lkl is the leakage inductance of the main coil n1, Lk2 is the leakage inductance of the secondary winding n2, and Lk3 is the leakage inductance of the induction coil n3. In the present embodiment, it is assumed that 疋Lm is l〇〇uH ’ Lkl and Lk2 are both luH. Since the coil n3 can shield the main coil n1 by the secondary coil n2, Lk3 is a higher value 2 uH. The resistor Rsen represents the equivalent resistance of the actual circuit in this embodiment. In the breakdown condition, since Lm is much larger than Lk2, the voltage Vm across the magnetic inductance Lm is about half of the input voltage vin, and Vn2 is 0°Vn3 because of its time constant (Lk3/Rsen=2uH/10kOhm=0.2 Nsec) is much smaller than lnsec, so Vn3 is an instantaneous approximation of Vm. Fig. 10C is a diagram showing the actual waveforms of Vn2, Vn3 and IQ2 of the power transformer 8〇〇 measured in practice. At the moment when the breakdown occurs, it can be found that there is a significant noise in the actual waveform of Vn3. Since the switching signal on which Qp is turned on is a reliable and noise-free signal, the sensing signal Vn3 of this embodiment is not suitable. To indicate when Qp is turned on. FIG. 11A illustrates the improved coil structure of the power transformer 8〇〇. The main coil n1 is placed in the innermost layer, the induction coil n3 is placed in the middle, and the secondary coil n2 is placed in the outermost layer. In the coil structure of this embodiment, there is a good coupling relationship between the coil n1 and the coil n3, and due to the shielding effect of the 201018068---ioc/u made by the coil n3, the main coil ni and the secondary The coupling relationship between the coils n2 is poor. Figure 11B is a diagram showing the equivalent circuit model of the power transformer 800 of Figure 11A. The main switch Qp is turned on under the breakdown condition, and the main switch QP and the gold-oxygen half-field effect transistor Q2 are both turned on. In the present embodiment, it is assumed that Lk2 is 2uH' Lk3 is luH. In the case of breakdown, Vm is 2/3Vin. Figure 11C shows the actual waveform of Vn3, the waveform of which is very similar to the waveform predicted by the equivalent circuit module in the φ diagram. During the period of breakdown, Vn3 will quickly jump to 2/3Vin. And in the similar situation of the Vn2 waveforms of both FIG. 11C and FIG. 10C, the waveform of Vn3 in FIG. 11C has less noise' and the glitch value of the waveform of Vn3 in FIG. 11C is only the glitch in FIG. half. The embodiment of Fig. 11A has another variation in that the coil is configured to place the coil n2 in the innermost layer and to place the coil ni on the outermost layer, i.e., to align the coil n1 and the coil n2 of Fig. 11A, such an embodiment. The equivalent circuit module is the same as FIG. 11B of the foregoing embodiment. FIG. 12A illustrates another improved coil configuration of the power transformer 800. The secondary coil η2 is placed in the innermost layer, and the main coil η1 is placed in the middle. The induction coil n3 is placed on the outermost layer. In the coil structure of the present embodiment, the coupling relationship between the coil n1 and the coil n2 and the surface relationship between the coil ηι and the coil α are very good, and the shielding effect caused by the coil n1 makes the secondary coil n2 The coupling relationship with the induction coil n3 is poor. FIG. 12B illustrates an equivalent circuit module of the power transformer 800. Among them, 17 201018068.c/n The main switch Qp is turned on under the breakdown condition, at this time, the main switch Qp and the gold oxide half field effect transistor Q2 are all turned on. Since the coils n2 and n3 are respectively on both sides of the coil n1, the coils n1, n2 and n3 can be regarded as two transformers. In this embodiment, both Lk2 and Lk3 are set to luH. Figure 12C shows the actual waveform of Vn3, the waveform of which is very similar to the waveform predicted by the power transformer module of Figure 12B. During the breakdown, the value of Vn3 will quickly jump to Vin. And in the similar situation of the Vn2 waveform of both FIG. 12C and FIG. loc, the waveform of Vn3 in FIG. 12C is a clean, noise-free, and non-surge step waveform. Therefore, the coil structure of Fig. 12A has an optimum Vn3 waveform. The embodiment of Fig. 12A has another variation in that the coil is disposed in such a position that the coil n3 is placed in the innermost layer and the coil n2 is placed on the outermost layer, that is, the innermost layer of the loop n2 of Fig. 12A is aligned with the outermost coil n3. The equivalent circuit module of such an embodiment is the same as the above-described embodiment FIG. 12B. The above-described controlled-coupling Φ sense winding scheme can be used for a forward type transformer or for different applications. Fields such as half-bridge converters and full-bridge converters. Further, as shown in Fig. 13, it can also be applied to a flyback transformer and operates in a continuous conduction mode. As shown in Fig. 13, its power transformer 1300 is similar to the power transformer 8A of Fig. 8, and the qi controller 131A is similar to the Q2 controller 820 of Fig. 8. As shown in Fig. 14, when the main switch Qp is turned on outside the prediction time 18 i〇c/n φ ❹ 201018068 In this case, the = closing time point Τ6 occurs. In the oxygen half-field effect day, the Japanese Qi serious city light wave will cause gold, and the Qp will open the closed-circuit oxygen half-field effect transistor Q1. Therefore, the two points T6 are immediately turned off, as shown by the IQ1 waveform in Figure 14. The reduction of current in the limit = the release = on the 'though it is not used in the "and within the scope" can be made a little more change and the spirit of the spirit of the scope of the application of the patent scope _ defined by the protection of the invention [pattern Brief Description] The pressure converter =? is a traditional forward type with a self-rotating synchronous rectifier. Figure 2 is a diagram! The important signal type of the conventional forward type transformer = the conventional forward direction with the predictive synchronous rectification control circuit. FIG. 4 shows the important signal shape of the conventional forward type transformer of FIG. 3. FIG. 5 shows the conventional forward type transformer. Breakdown chart. / Figure. The figure is shown as a schematic diagram of a conventional synchronous full pressure transformer with a pulse transformer. FIG. 8 is a schematic diagram showing an important signal waveform of a conventional forward-type transformer of FIG. 6. FIG. 8 is a schematic diagram of a DC-DC transformer having an induction coil according to an embodiment of the present invention. Β $正 19 201018068 x _. . _______J〇c/n Figure 9 is a diagram showing the important signal waveforms of the forward transformer of Figure 8. FIG. 10A is a schematic diagram showing the structure of a coil of a power transformer according to an embodiment of the invention. FIG. 10B is a diagram showing an equivalent circuit module of FIG. FIG. 10C is a waveform diagram of the signal in the breakdown state of FIG. 10B. Figure 11A is a schematic view showing the structure of an improved coil according to an embodiment of the present invention. Figure 11B is a diagram showing the equivalent circuit module of Figure 11A. FIG. 11C is a waveform diagram of the signal in the breakdown state of FIG. 10B. Figure 12A is a schematic illustration of a modified coil structure in accordance with another embodiment of the present invention. Figure 12B is taken as the equivalent circuit module of Figure 12A. FIG. 12C is a waveform diagram of the signal in the breakdown state of FIG. 12B. Fig. 13 is a diagram showing a synchronous rectification flyback type transformer of a continuous conduction mode according to an embodiment of the present invention. FIG. 14 is a diagram showing signal waveforms of the flyback transformer of FIG. 〇 [Main component symbol description] 310, 320: Predictive synchronous rectification controller 610, 620: synchronous rectification controller 800, 1300: power transformer 810, 1310: Qi controller 820: Q2 controller Q1, Q2: gold oxygen half Effect transistor QP: power switch 20 .Joc/n 201018068

Cl, Co: Capacitor D1: Forward diode D2: Freewheel diode TL431: Diode Vin: Input voltage Vout: Output voltage IQ1, IQ2: Current signal Trl: Power transformer ® Tr2: Pulse transformer

Vpt : Qp turn-on and turn-off signals

Vn2, Vn3: voltage signal nl: main coil n2: secondary coil n3: induction coil lout: output current

Lo: Inductance parameters Vds, Vgp, Vgs, Vgsl, Vgs2, Vm: voltage ΤΙ, T2, T3, T5, T6, T6', T7: time point Tdell, Tdel2: delay time Lm: magnetic inductance Lkl of the power transformer 800, Lk2, Lk3: leakage inductance of the coil Rl, Rsen: resistance 21

Claims (1)

Aoc/π 201018068 X. Patent application: 1. A synchronous rectified DC-to-DC transformer, comprising: a power transformer comprising: - a core; a main coil wound around the core and used to receive the synchronous rectified DC-DC An input voltage of the transformer; a secondary coil wound around the core and configured to provide energy for outputting the current of one of the synchronous DC current transformers; and an induction coil wound around the core and providing an inductive signal; a first diode, coupled to the secondary coil for rectifying the wheel current; a first gold-oxygen half field effect transistor 'parallelly coupled to the first diode; and a first controller coupled Connected to the inductive coil and the first metal oxide half field effect transistor 'and open and close the first metal oxide half field effect transistor according to the sensing signal. 2. A synchronous rectified DC-to-DC transformer as described in claim 1, wherein the primary coil is interposed between the secondary coil and the induction coil. 3. The synchronous rectified DC-to-DC converter of claim 2, wherein the main coil is wound around the secondary coil, and the induction coil is wound around the main coil. 4. A synchronous rectified DC-to-DC transformer as described in claim 2, wherein the main coil is wound around the induction coil, and the secondary 22 201018068 coil is wound around the main coil. 5. A synchronous rectified DC-to-DC transformer as described in claim 1 wherein the induction coil is interposed between the primary coil and the secondary coil. 6. The synchronous rectified DC-pair DC transformer of claim 5, wherein the induction coil is wound around the main coil, and the secondary coil is wound around the induction coil. 7. The synchronous rectified DC-to-spindle transformer of claim 5, wherein the induction coil is wound around the secondary coil, and the main coil is wound around the induction coil. Wrong...8 For the synchronous rectification DC-to-DC transformer described in the scope of the patent application, the sensing signal is a voltage signal. For example, the synchronous rectification DC to DC 1 thief mentioned in the first paragraph of the patent application scope, wherein the first controller corresponds to the sense of the deer Flow transformer, transformer. The synchronous rectification DC-to-DC-DC converter of the above-mentioned item is a forward type 23 201018068 12· The synchronous rectification DC-DC transformer described in claim 11 of the patent scope further includes: a second diode And coupled to the secondary coil and the first diode for rectifying the wheel current; a second gold-oxygen half field effect transistor coupled in parallel to the second diode; and day a-second The controller is coupled to the induction coil and the second MOS field-effect transistor and opens or closes the second MOS field effect transistor according to the shouting. ^13. The synchronous rectification DC-to-DC transformer of claim 12, wherein the second controller opens the second oxy-half field effect transistor corresponding to a rising edge of a first period of the inductive signal And the time point of closing the second field effect transistor is estimated by the falling edge of the first phase of the sensing; the second period is earlier than the sounding of the tune The synchronous rectification DC-to-direct-voltage converter is described in the above-mentioned, and the synchronous rectification DC-to-DC voltage transformation 11 is - a half-bridge rheology, such as the synchronous rectification DC-to-straight transformer step rectification described in the first item. The DC-to-DC converter is a synchronous transformer flow transformer as described in item 1 of the full bridge type. Synchronous rectification DC to DC Lai 11 - flyback 24