CN105245098A - Pulse frequency modulator for power supply converter and modulation method - Google Patents
Pulse frequency modulator for power supply converter and modulation method Download PDFInfo
- Publication number
- CN105245098A CN105245098A CN201410311591.4A CN201410311591A CN105245098A CN 105245098 A CN105245098 A CN 105245098A CN 201410311591 A CN201410311591 A CN 201410311591A CN 105245098 A CN105245098 A CN 105245098A
- Authority
- CN
- China
- Prior art keywords
- turn
- time
- control circuit
- supply convertor
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title abstract description 29
- 238000005070 sampling Methods 0.000 description 15
- 230000008859 change Effects 0.000 description 10
- 230000001276 controlling effect Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000001939 inductive effect Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 230000001965 increasing effect Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000009514 concussion Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a pulse frequency modulator for a power supply converter, which comprises a turn-off time control circuit and a turn-on time control circuit, wherein the turn-off time control circuit controls the turn-off time according to output voltage when a switching circuit of the power supply converter is turned-off, and the turn-off time control circuit gives out a turn-on signal when timing of the turn-off time is over; and the turn-on time control circuit controls the turn-on time by using a method of peak current control according to input current and input voltage when the switching circuit of the power supply converter is turned on, and the turn-on time control circuit gives out a turn-off signal when timing of the turn-on time is over. According to the invention, the turn-on time and the turn-off time controlled by the pulser modulator are adjustable, so that the switching frequency is enabled to be monotonously changed along with the input voltage and a load, the switching frequency is low when the load is light, the switching frequency is high when the load is heavy, the switching frequency is high when the input voltage is low, the switching frequency is low when the input voltage is high, and the efficiency of the converter can be effectively improved when the load is light and the voltage is high.
Description
Technical field
The present invention relates to pulse frequency modulated technical field, particularly change the pulse frequency modulated method of duty ratio.
Background technology
Pulse frequency modulated method (PFM) is that a kind of frequency of pulse of regulation control switch pipe break-make is with load variations and the control method making output voltage constant.According to the difference of modulation system, PFM mainly can be divided into: constant pulse width PFM, hop cycle PFM and variable duty cycle PFM.Constant pulse width PFM refers to that switching pulse width is constant square-wave signal, and switching frequency changes with load and input voltage, and this PFM mode is used in resonance class circuit, as LLC; The modulation signal of hop cycle PFM is based on the pulse control signal of " constant-breadth constant frequency ".Under full load, pulse control signal is full frequency pulse control signal is full frequency (being set to highest frequency) output, when load lightens, just have some control cycles to be skipped, in the cycle be skipped, power tube is in off state always, namely by regulating the number of hop cycle to change equivalent switching frequency, thus realizing frequency conversion, this PFM mode is mainly used in improving underloading or no-load efficiency, inapplicable wide loading range; Variable duty cycle PFM refer to by change switching frequency realize change in duty cycle, it is a kind of sensu lato PFM pattern, be widely used in traditional disresonance class DC-DC converter, the main implementation method of variable duty cycle PFM mainly contains fixing ON time and controls, and the fixing turn-off time controls and Hysteresis control etc.
Figure 1 shows that the PFM control circuit in known technology, as Fig. 1, control circuit sampling and outputting voltage, and calculating is compared together with reference value, produce the control signal that control switch pipe is opened or turned off.Fig. 1 (a) is depicted as fixing ON time and controls, namely the ON time ton of switch is constant, and regulate duty ratio by the turn-off time changing switch, output voltage Vout and the reference value Vref of control circuit sampled power circuit compare, when Vout equals Vref, shutdown switch; Fig. 1 (b) is depicted as the control of fixing turn-off time, the turn-off time toff bis-of switch is constant, and regulate duty ratio by the service time changing switch, output voltage Vout and the reference value Vref of control circuit sampled power circuit compare, when Vout equals Vref, open switch; Fig. 1 (c) is depicted as Hysteresis control, output voltage Vout and the higher limit Vref1 and lower limit Vref2 of control circuit sampled power circuit compare, when output voltage Vout opens switch lower than during lower limit Vref2, and output voltage Vout shutdown switch when being greater than higher limit Vref1, under this control mode, service time and turn-off time are all changes.
Variable duty cycle PFM method in known technology, switching frequency is not by the impact of input voltage change, therefore the switching frequency in whole input voltage range can not be optimized, especially in the occasion that input voltage range is wider, if can not switching frequency in optimized circuit, the efficiency of circuit also namely can not be improved further.
Summary of the invention
The technical problem to be solved in the present invention is, be provided for pulse frequency modulated (PFM) device and the modulator approach thereof of supply convertor, this pulse frequency modulator can adjust switching frequency according to the change of input voltage and load simultaneously, reaches the object optimizing switching frequency.
Pulse frequency modulator for supply convertor of the present invention, comprising: supply convertor, has an input, accepts input voltage, an output, exports output voltage, and switching circuit, pulse frequency modulator, for controlling the switching frequency of the switching circuit of described supply convertor, comprise: a turn-off time control circuit, when described switching circuit turns off, the turn-off time of switching circuit according to the output voltage control of the output of described supply convertor, turn-off time timing terminates, described turn-off time control circuit sends opens signal, and an ON time control circuit, during described switching circuit conducting, the ON time of described switching circuit is controlled according to the input voltage of the input of described supply convertor and input current, ON time timing terminates, described ON time control circuit sends cut-off signals.
In one embodiment of the present invention, described supply convertor is a disresonance type DC dc converter, and described disresonance type DC dc converter is operated in non-continuous mode, can be the BUCK converter working in non-continuous mode in particular.
In one embodiment of the present invention, described turn-off time control circuit comprises a condenser network and a linearity control circuit, the output of described linearity control circuit is connected with described condenser network, for described condenser network charges, described linearity control circuit is sampled the output voltage of output of described supply convertor, the output voltage of described output is larger, and the output current of described linearity control circuit is less, otherwise then larger.
In one embodiment of the present invention, when the voltage of described capacitance cathode reaches turn-off time control reference value, turn-off time timing terminates, and sends and opens signal.
In one embodiment of the present invention, a described electric capacity two ends control switch in parallel, described control switch and described switching circuit synchronously turn on and off.
In one embodiment of the present invention, described turn-off time control circuit also comprises turn-off time control comparator, the positive input terminal of described comparator connects the positive pole of described capacitor, the negative input end input described turn-off time of described comparator controls reference value, the output of described comparator exports opens signal, when the voltage of described capacitance cathode reach a turn-off time control reference value time, turn-off time timing terminates, and described to open signal effective.
In one embodiment of the present invention, described ON time control circuit uses peak current control method, described ON time control circuit is sampled the input voltage of described supply convertor, and the fiducial value of peak value comparison method is calculated according to the sampled value of described input voltage, described ON time control circuit is sampled the input current of described supply convertor, when the sampled value of described input current reaches the fiducial value of described peak value comparison method, ON time timing terminates, and described cut-off signals is effective.
In one embodiment of the present invention, described pulse frequency modulator also comprises a logic controller, described logic controller receives described cut-off signals and describedly opens signal, and cut-off signals effectively and when opening invalidating signal, described logic controller exports cut-off signals; Open signal effectively and cut-off signals is invalid time, described logic controller exports and opens signal.
In one embodiment of the present invention, logic controller is a rest-set flip-flop, and the S termination of described rest-set flip-flop is received and opened signal, and the R termination of described rest-set flip-flop receives cut-off signals, the Q end of described rest-set flip-flop connects described switching circuit, and output switch control signal controls described switching circuit.
Present invention also offers the pulse frequency modulated method for supply convertor, comprise the following steps:
Step one judges that switching circuit is opening state or off state, if opening state then carries out step 2, if off state then carries out step 3;
Step 2 carries out service time timing according to output voltage values, at the end of service time, sends cut-off signals;
Step 3 carries out turn-off time timing according to input voltage and input current, at the end of the turn-off time, sends and opens signal.
In the present invention one preferred embodiment, described step 3, also comprises:
Step 3.1 uses a condenser network to carry out shutoff and controls timing;
Step 3.2 uses a linear controller to be the charging of described condenser network, and two inputs of described linear controller are the sampled value of output voltage and the reference value of output voltage respectively, and the output of described linear controller is the charging of described condenser network.
Step 3.3 is when the cathode voltage of described condenser network reaches shutoff control reference value, and turn-off time timing terminates, and sends and opens signal.
In the present invention one preferred embodiment, described step 2, also comprises:
Step 2.1 is sampled described input voltage, and utilizes it to calculate the fiducial value of input current;
Step 2.2 is sampled described input current, and compares the sampled value of input current and the fiducial value of described input current;
Step 2.3 is when the sampled value of described input current reaches the fiducial value of described input current, and ON time timing terminates, and sends cut-off signals.
Based on above-mentioned, the embodiment of the present invention proposes the pulse frequency modulator and the modulator approach that are used for supply convertor.Described pulse frequency modulator according to the turn-off time of output voltage modulation switch circuit, again according to input voltage and input current modulation switch circuit turn-on time.Base this, during underloading, switching frequency is low, heavy duty time switching frequency high, during low input, switching frequency is high, during high input voltage, switching frequency is low, effectively can improve the efficiency of converter when underloading and high pressure, in almost whole input voltage and loading range, all have higher efficiency.Very be applicable to wide input voltage range, and whole weight carries all higher occasion of efficiency requirements.In addition, because turn-on instant is variable, voltage gain curve is dull with frequency, should occasion at multiple module paralleling, can, by adding outer synchronizing frequency, be easy to realize parallel current-sharing, do not need additional current equalizing bus bar, control circuit is simple, and antijamming capability is strong, can realize the parallel connection of numerous module in theory.Switching frequency is with input voltage gain monotonically increasing characteristic, and for the occasion in current limliting or constant current application, the short circuit current limitation (constant current) being easy to realizing circuit controls.
For above-mentioned feature and advantage of the present invention can be become apparent, special embodiment below, and coordinate institute's accompanying drawings to be described in detail below.
Accompanying drawing explanation
Fig. 1 is the PFM control circuit in known technology.
Fig. 2 is a circuit structure block diagram of the invention process.
Fig. 3 is a particular circuit configurations block diagram of the invention process.
Fig. 4 is the circuit diagram of the present invention one specific embodiment.
Fig. 5 is the circuit diagram of the another specific embodiment of the present invention.
Fig. 6 is the flow chart of pulse frequency modulated method of the present invention.
Fig. 7 be pulse frequency modulated method of the present invention service time control method a specific embodiment.
Fig. 8 is a specific embodiment of the turn-off time control method of pulse frequency modulated method of the present invention.
Embodiment
With reference to the one exemplary embodiment in accompanying drawing, illustrate the present invention.In addition, all possibility parts, use the assembly/component of identical label to represent identical or similar portions in the drawings and the specific embodiments.
Refer to Fig. 2, the invention provides a kind of pulse frequency modulator for supply convertor, described pulse frequency modulator 21 provides switch controlling signal for described supply convertor 22.
Fig. 3 is structured flowchart of the present invention, comprises, supply convertor 32 and pulse frequency modulator 31.Described supply convertor 32 more comprises a switching circuit 321.Described pulse frequency modulator 31 comprises: turn-off time control circuit 311, adopt the control method of voltage control loop, the output voltage Uout receiving supply convertor is used for being a shutoff timing circuit charging through computing output current signal, when turning off timing circuit timing and completing, open signal Con effective, control switch circuit debugging; ON time control circuit 312, receives input voltage Uin and the input current iin of supply convertor, adopts the method for peak value comparison method, carry out ON time Ton timing, when when closed, Ton timing completes, cut-off signals Coff is effective, control switch circuit shut-down; Logic control circuit 313, receive and describedly open signal Con and described cut-off signals Coff, the switching circuit of described supply convertor is controlled after logical operation, described logical operation refers to, when described cut-off signals shutdown switch circuit effectively and when opening invalidating signal, when described open signal effectively and cut-off signals is invalid time open described switching circuit.
Referring again to the circuit diagram that Fig. 4, Fig. 4 are the present invention one specific embodiment, in the present embodiment, supply convertor 42 is a disresonance class DC supply convertor, and the present embodiment employs a Buck converter in particular.Wherein switching circuit 421 comprises a controlled power switch S w, can be controlled the output voltage Uout of supply convertor 42 by the duty ratio turned on and off controlling controlled power switch S w.
The present embodiment also comprises pulse frequency modulator 41, described pulse frequency modulator 41 comprises turn-off time control circuit 411, described turn-off time control circuit 411 only carries out turn-off time timing when switching circuit 421 is in off state, described turn-off time control circuit 411 comprises linearity control circuit 4111 and turn-off time timing circuit 4112, and described linearity control circuit 4111 is charged for described turn-off time timing circuit 4112.
Described linearity control circuit 4111 comprises: output voltage sampling circuit Ku and linear regulator PID, the output voltage Uout of described output voltage sampling circuit Ku sampling supply convertor, and the result Uc_out of sampling is exported to linear regulator PID, described linear regulator PID also receives an output voltage reference value Uo_ref simultaneously, equals output voltage reference value Uo_ref with the sampled value Uc_out controlling output voltage.Described output voltage Uout is larger, and the output current of described linear regulator PID is less.In particular, described in an optimal enforcement example, linear regulator PID is a spaning waveguide operational amplifier.
Described turn-off time timing circuit 4112 comprises a condenser network CC, and the output of described linear regulator is connected with described condenser network CC, is its charging, utilizing capacitor charging to need certain time length to opening control reference value Uc_ref, coming for turn-off time timing.In addition, if output voltage Uout is larger, the output current of linear regulator PID is less, and the charging interval of condenser network CC is longer, and the turn-off time of pulse frequency modulator 41 control switch circuit 421 is longer, makes its switching frequency less.Described turn-off time timing circuit 4112 also comprises a charge and discharge control switch S c, and described charge and discharge control switch S c is in parallel with described condenser network Cc, controls described turn-off time timing circuit and only carries out turn-off time timing when switching circuit 421 is in shutoff.When switching circuit is in opening state, described charge and discharge control switch S c is in conducting state, makes the turn-on voltage of voltage clamping at charge and discharge control switch S c of described condenser network Cc positive pole; When switching circuit is in off state, described charge and discharge control switch S c is in off state, and the cathode voltage of described condenser network Cc is increased along with the increase in charging interval, and turn-off time timing circuit 4112 carries out off state timing.In the present invention, charge and discharge control switch S c uses identical switch controlling signal with switching circuit Sw, so they open or turn off simultaneously.
Described turn-off time timing circuit 4112 more comprises a shutoff and controls comparator Copm_1, comprise positive input terminal, negative input end and an output, turn off the positive input terminal controlling comparator Copm_1 to be connected with the positive pole of described condenser network Cc, receive input voltage UCc, the described negative input end controlling comparator Copm_1 that turns off receives described shutoff control reference value Uc_ref, the described output turning off control comparator Copm_1 exports opens signal, when the cathode voltage UCc of described condenser network Cc is less than described shutoff control reference value Uc_ref, the described output output low level voltage turning off control comparator Copm_1, when the cathode voltage UCc of described condenser network Cc reaches described shutoff control reference value Uc_ref, the described output voltage opening the output controlling comparator can be high level from low transition, now opens signal effective.
Described pulse frequency modulator 41 also comprises ON time control circuit 412, described ON time control circuit 412 comprises input voltage sample circuit kx+b, input current sample circuit Ki and conducting control comparator Copm_2, sampled result Ipref is also inputed to conducting control comparator by described input voltage sampling circuit samples input voltage Uin, in particular, described input voltage sample circuit kx+b, first sampling import and export voltage, then sampled result is obtained through a linear scale counting circuit, and using sampled result Ipref as the benchmark of peak value comparison method, described input current sample circuit Ki sampling input current iin, and sampled result is is inputed to conducting control comparator, in particular, described input current sample circuit Ki is made up of current sensor, such as Hall element, the electric current of described current sensor sampling input, its output connects a bleeder circuit, the input current of sampling is converted to a magnitude of voltage.Described conducting control comparator Copm_2 mono-preferably embodiment is a comparator, comprise positive input terminal, negative input end and an output, in embodiment, described conducting controls the sampled result is of the positive input terminal reception input current sample circuit of comparator, described conducting controls the sampled result Ipref of the negative input end reception input voltage sample circuit of comparator, and the output that described conducting controls comparator exports cut-off signals.When the sampled result is of described input current sample circuit is less than the sampled result Ipref of input voltage sample circuit, described in convince that logical to control comparator Copm_2 output end voltage be low level by patient analysis; When the sampled result is of described input current sample circuit reaches the sampled result Ipref of input voltage sample circuit, the described output end voltage opening comparator can be high level from low level redirect, and now cut-off signals is effective.ON time control circuit 412 is a kind of specific embodiments of peak value comparison method, but the present invention is not limited to this.
Pulse frequency modulator 41 also comprises logic control circuit 413, and logic control circuit 413 described in the present embodiment is a rest-set flip-flop, and the S of described rest-set flip-flop end is connected with the output of described turn-off time control circuit 411, receives describedly to open signal; The R end of described rest-set flip-flop is connected with the output of described ON time control circuit 412, receives described cut-off signals; The output Q of described rest-set flip-flop is as the output of pulse frequency modulator 41, and the output of described pulse frequency modulator 41 is connected with the control end of the switch S w in described switching circuit, and control switch Sw turns on and off.When described open signal effective time, output Q exports high level, controls described switch S w open-minded, and when described cut-off signals is effective, output Q output low level, controls described switch S w and turn off.
Now several important process mode of the circuit of Fig. 4 are illustrated as follows:
Before mode 1 [t0-t1] the t0 moment, power switch SW is in off state, and electric capacity CC charge-discharge circuit control switch Sc is also in off state, electric capacity CC charges via linear regulator PID, in the t0 moment, electric capacity CC cathode voltage rises to Uc_ref, comparator Comp_1 output switching activity, by low high jump, rest-set flip-flop S end is put 1, Q and is exported high level, power switch SW conducting, diode Df ends, and inductive current rises gradually.While power switch SW Continuity signal sends, electric capacity CC charge-discharge circuit control switch Sc also receives on signal conduction, and electric capacity CC is by control switch Sc repid discharge, and in the t1 moment, electric capacity CC discharges into zero end.
After mode 2 [t1-t2] t1, because control switch Sc is still in conducting state, electric capacity CC cannot charge, comparator Comp_1 output switching activity, jumped low by height, rest-set flip-flop S end sets to 0, again because now peak current sampling is does not reach Ipref, comparator Comp_2 output low level, rest-set flip-flop R end also sets to 0, so now rest-set flip-flop output Q keeps the high level in mode 1, power switch SW continues conducting, diode Df ends, inductive current continues to rise, peak current sampling is also continues to rise, the t2 moment, is rises to Ipref, comparator Comp_2 output switching activity, by low high jump, rest-set flip-flop R end puts 1, Q output level is jumped low by height, power switch SW turns off, control switch Sc turns off, this mode terminates.
After mode 3 [t2-t3] t2, power switch SW turns off, diode Df conducting afterflow, and inductive current starts to decline, and peak current sampling is drops quickly to zero, and comparator Comp_2 output switching activity, is jumped low by height, and rest-set flip-flop R end sets to 0; Electric capacity CC is turned off by control switch Sc, and the current source IC that electric capacity CC generates via voltage regulator charges, before electric capacity CC voltage does not reach Uc_ref, it is low that comparator Comp_l1 exports always, and rest-set flip-flop S end sets to 0, and Q exports and keeps low level, SW, Sc keep off state.In the t3 moment, inductive current drops to zero, and this mode terminates.
After mode 4 [t3-t4] t3, power switch SW turns off, and diode Df afterflow turns off naturally to zero, and inductance L r electric current is maintained zero, is continued to provide energy to load by output capacitance Co.Before electric capacity CC voltage does not reach Uc_ref, comparator Comp_1 and Comp_2 does not all overturn, and rest-set flip-flop keeps mode 3 state.In the t4 moment, electric capacity CC terminal voltage rises to Uc_ref, comparator Comp_l1 output switching activity, and by low high jump, rest-set flip-flop S end is put 1, Q and exported high level, and power switch SW conducting, diode Df ends, and inductive current rises gradually.Enter next cycle period afterwards.
Can be found by analysis chart 4, the size of input voltage Uin determines the size of peak current benchmark Ipref, input voltage is higher, the peak current benchmark Ipref that input voltage sample circuit obtains is larger, longer the time-to-climb of input circuit sampled value is, the ON time of switching circuit SW is longer, under identical load and output voltage condition, whole switch periods is longer, and switching frequency is lower; The length of the decision turn-off time of turn-off time control circuit, load is heavier, the output current of linear regulator PID is larger, the timing time of turn-off time timing circuit is shorter, the turn-off time of switching circuit is shorter, and under identical input voltage condition, ON time is identical, therefore whole switch periods is shorter, and switching frequency is higher.Therefore, all good variable frequency control can be realized at whole input voltage and loading range the present invention.
Fig. 5 is another specific embodiment of the present invention, with Fig. 4 unlike, supply convertor 52 input in the present embodiment and output isolation, in the output voltage sampling circuit of pulse frequency modulator 51, add an optocoupler accordingly, the output of linear regulator PID is delivered to shutoff timing circuit.
The present invention also provides a kind of method of pulse frequency modulated, for disresonance type DC/DC converter, particularly work in the disresonance type DC/DC converter of non-continuous mode (DCM), its basic thought is: the input current of sampling power source change device also goes with peak current control method the ON time controlling power switch pipe; Go with output voltage loop the turn-off time controlling power switch pipe, ON time and turn-off time sum are whole switch periods.Obtain different ON time under different input voltages, under different loading conditions, obtain the different turn-off times, thus obtain different switch periods, can variable frequency control be realized.
Fig. 6 is the flow chart of pulse frequency modulated method of the present invention, specifically comprises:
Step 61 judges that switching circuit is opening state or off state, if opening state then carry out step 62, if off state then carry out step 63;
Step 62 carries out ON time control according to output voltage values, at the end of ON time, sends cut-off signals;
Step 63 carries out turn-off time control according to input voltage and input current, at the end of the turn-off time, sends and opens signal.
Fig. 7 is the concrete steps controlled the turn-off time of the present invention, comprising:
Step 701 is sampled described input voltage, and utilizes it to calculate the fiducial value of input current;
Step 702 is sampled described input current, and compares the sampled value of input current and the fiducial value of described input current;
Step 703 is when the sampled value of described input current reaches the fiducial value of described input current, and ON time timing terminates, and sends cut-off signals.
Fig. 8 is the concrete steps controlled the turn-off time of the present invention, comprising:
Step 801 uses a condenser network to carry out shutoff and controls timing;
Step 802 uses a linear controller to be the charging of described condenser network, and two inputs of described linear controller are the sampled value of output voltage and the reference value of output voltage respectively, and the output of described linear controller is the charging of described condenser network.
Step 803 is when the cathode voltage of described condenser network reaches shutoff control reference value, and turn-off time timing terminates, and sends and opens signal.
In sum, the embodiment of the present invention proposes the pulse frequency modulator and the modulator approach that are used for supply convertor.Described pulse frequency modulator can according to the status adjustment switching frequency of the input and output of supply convertor, during underloading, switching frequency is low, during heavy duty, switching frequency is high, during low input, switching frequency is high, during high input voltage, switching frequency is low, effectively can improve the efficiency of converter when underloading and high pressure, in almost whole input voltage and loading range, all there is higher efficiency.Very be applicable to wide input voltage range, and whole weight carries all higher occasion of efficiency requirements.
The more important thing is, ON time controls to have employed peak current control method, and circuit working does not deposit subharmonic concussion problem in a PWM mode under DCMPFM pattern, and do not need slope compensation, simplified control circuit designs.The advantage of peak value comparison method is: 1) transient state closed loop response is than very fast, to the change transient response of the change of input voltage and output loading also than comparatively fast; 2) control ring is easy to design; 3) there is simple magnetic balance function automatically; 4) there is instantaneous peak current current-limiting function etc.Because ON time is controlled, voltage gain curve is dull with frequency, should occasion at multiple module paralleling, by adding outer synchronizing frequency, can be easy to realize parallel current-sharing, not need additional current equalizing bus bar, control circuit is simple, and antijamming capability is strong, can realize the parallel connection of numerous module in theory.
Although the present invention discloses as above with embodiment; so itself and be not used to limit the present invention; have in any art and usually know the knowledgeable; without departing from the spirit and scope of the present invention; when doing a little change and retouching, therefore protection scope of the present invention is when being as the criterion depending on the accompanying claim person of defining.
Claims (12)
1., for the pulse frequency modulator of supply convertor, comprising:
One supply convertor, has an input, accepts input voltage, an output, exports output voltage, and switching circuit,
One pulse frequency modulator, for controlling the switching frequency of the switching circuit of described supply convertor, is characterized in that, comprising:
One turn-off time control circuit, when described switching circuit turns off, the turn-off time of switching circuit according to the output voltage control of the output of described supply convertor, turn-off time timing terminates, and described turn-off time control circuit sends opens signal,
One ON time control circuit, during described switching circuit conducting, control the ON time of described switching circuit according to the input voltage of the input of described supply convertor and input current, ON time timing terminates, and described ON time control circuit sends cut-off signals.
2. as claimed in claim 1 for the pulse frequency modulator of supply convertor, it is characterized in that, described supply convertor is a disresonance type DC dc converter, and described disresonance type DC dc converter is operated in non-continuous mode.
3. as claimed in claim 1 for the pulse frequency modulator of supply convertor, it is characterized in that, described turn-off time control circuit comprises a turn-off time timing circuit and a linearity control circuit, the output of described linearity control circuit is connected with described turn-off time timing circuit, for described turn-off time timing circuit charging, described linearity control circuit is sampled the output voltage of output of described supply convertor, the output voltage of described output is larger, the output current of described linearity control circuit is less, otherwise then larger
.
4. as claimed in claim 3 for the pulse frequency modulator of supply convertor, it is characterized in that, described turn-off time timing circuit is a condenser network, and when the voltage of described capacitance cathode reaches turn-off time control reference value, turn-off time timing terminates.
5. as claimed in claim 4 for the pulse frequency modulator of supply convertor, it is characterized in that, a described electric capacity two ends control switch in parallel, described control switch and described switching circuit synchronously turn on and off.
6. as claimed in claim 4 for the pulse frequency modulator of supply convertor, it is characterized in that, described turn-off time control circuit also comprises turn-off time control comparator, the positive input terminal of described comparator connects the positive pole of described capacitor, the negative input end input described turn-off time of described comparator controls reference value, the output of described comparator exports opens signal, when the voltage of described capacitance cathode reaches turn-off time control reference value, turn-off time timing terminates, and described to open signal effective.
7. as claimed in claim 1 for the pulse frequency modulator of supply convertor, it is characterized in that, described ON time control circuit uses peak current control method, described ON time control circuit is sampled the input voltage of described supply convertor, and the fiducial value of peak value comparison method is calculated according to the sampled value of described input voltage, described ON time control circuit is sampled the input current of described supply convertor, when the sampled value of described input current reaches the fiducial value of described peak value comparison method, ON time timing terminates.
8. as claimed in claim 1 for the pulse frequency modulator of supply convertor, it is characterized in that, described pulse frequency modulator also comprises a logic controller, described logic controller receives described cut-off signals and describedly opens signal, cut-off signals is effective and when opening invalidating signal, described logic controller exports cut-off signals; Open signal effectively and cut-off signals is invalid time, described logic controller exports and opens signal.
9. as claimed in claim 8 for the pulse frequency modulator of supply convertor, it is characterized in that, logic controller is a rest-set flip-flop, the S termination of described rest-set flip-flop is received and is opened signal, the R termination of described rest-set flip-flop receives cut-off signals, the Q end of described rest-set flip-flop connects described switching circuit, and output switch control signal controls described switching circuit.
10., for the pulse frequency modulated method of supply convertor, it is characterized in that, comprise the following steps:
Step one judges that switching circuit is opening state or off state, if opening state then carries out step 2, if off state then carries out step 3;
Step 2 carries out ON time timing according to output voltage values, at the end of ON time, sends cut-off signals;
Step 3 carries out turn-off time timing according to input voltage and input current, at the end of the turn-off time, sends and opens signal.
11. as claimed in claim 10 for the pulse frequency modulated method of supply convertor, and it is characterized in that, described step 3, also comprises:
Step 3.1 uses a condenser network to carry out shutoff and controls timing;
Step 3.2 uses a linearity control circuit to be the charging of described condenser network, and two inputs of described linearity control circuit are the sampled value of output voltage and the reference value of output voltage respectively, and the output of described linearity control circuit is the charging of described condenser network;
Step 3.3 is when the cathode voltage of described condenser network reaches shutoff control reference value, and turn-off time timing terminates, and sends and opens signal.
12. as claimed in claim 10 for the pulse frequency modulated method of supply convertor, and it is characterized in that, described step 2, also comprises:
Step 2.1 is sampled described input voltage, and utilizes it to calculate the fiducial value of input current;
Step 2.2 is sampled described input current, and compares the sampled value of input current and the fiducial value of described input current;
Step 2.3 is when the sampled value of described input current reaches the fiducial value of described input current, and ON time timing terminates, and sends cut-off signals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410311591.4A CN105245098B (en) | 2014-07-02 | 2014-07-02 | Pulse frequency modulator and modulator approach for supply convertor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410311591.4A CN105245098B (en) | 2014-07-02 | 2014-07-02 | Pulse frequency modulator and modulator approach for supply convertor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105245098A true CN105245098A (en) | 2016-01-13 |
| CN105245098B CN105245098B (en) | 2019-02-12 |
Family
ID=55042627
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410311591.4A Active CN105245098B (en) | 2014-07-02 | 2014-07-02 | Pulse frequency modulator and modulator approach for supply convertor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105245098B (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106505860A (en) * | 2016-11-04 | 2017-03-15 | 深圳市华星光电技术有限公司 | A kind of output control method, output control system and liquid crystal display |
| CN106602861A (en) * | 2016-12-19 | 2017-04-26 | 深圳市华星光电技术有限公司 | Control circuit improving power factor correction conversion efficiency |
| CN107370366A (en) * | 2017-08-22 | 2017-11-21 | 无锡瓴芯电子科技有限公司 | A kind of voltage-dropping type DC DC changer systems |
| CN107634654A (en) * | 2016-07-13 | 2018-01-26 | 光宝电子(广州)有限公司 | Resonance conversion device and its control method |
| CN107994760A (en) * | 2016-10-27 | 2018-05-04 | 上海儒竞电子科技有限公司 | A kind of pulse modulation method and system |
| WO2019062263A1 (en) * | 2017-09-27 | 2019-04-04 | 广州金升阳科技有限公司 | Control method for asymmetric half-bridge flyback circuit, and circuit |
| CN109660112A (en) * | 2017-10-11 | 2019-04-19 | 英飞凌科技股份有限公司 | The control of switching regulaor |
| CN110120204A (en) * | 2019-04-04 | 2019-08-13 | 惠科股份有限公司 | Driving method of power supply driving module, power supply driving module and display device |
| CN110719095A (en) * | 2018-07-12 | 2020-01-21 | 浙江海利普电子科技有限公司 | Power supply circuit and method for monitoring state of load supplied by power supply circuit |
| CN112492722A (en) * | 2019-08-23 | 2021-03-12 | 圣邦微电子（北京）股份有限公司 | LED drive circuit and control circuit thereof |
| CN113315380A (en) * | 2021-05-25 | 2021-08-27 | 上海晶丰明源半导体股份有限公司 | Switching power supply control circuit, system and control method |
| WO2021175002A1 (en) * | 2020-03-06 | 2021-09-10 | Shunzhu Tao | A resonant circuit converter and control method |
| CN115189561A (en) * | 2022-06-22 | 2022-10-14 | 骏盈半导体(上海)有限公司 | CFT control circuit with adjustable frequency |
| CN117526717A (en) * | 2024-01-03 | 2024-02-06 | 杰华特微电子股份有限公司 | Frequency adjusting circuit and method for switching power supply and switching power supply |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6788038B1 (en) * | 2003-01-29 | 2004-09-07 | National Semiconductor Corporation | Apparatus and method for deactivating an on-switch of a circuit for a variable time interval |
| CN1561570A (en) * | 2001-07-20 | 2005-01-05 | 皇家菲利浦电子有限公司 | Oscillating circuit, converter with such oscillating circuit, and preconditioner with such converter |
| CN1855680A (en) * | 2005-04-26 | 2006-11-01 | 美国芯源系统股份有限公司 | Controlling method of switching power supply and product using it |
| CN101677206A (en) * | 2008-09-15 | 2010-03-24 | 电力集成公司 | Method and apparatus to reduce line current harmonics from a power supply |
| JP2010183723A (en) * | 2009-02-05 | 2010-08-19 | Mitsumi Electric Co Ltd | Dc-dc converter and switching control circuit |
| US20110194316A1 (en) * | 2010-02-09 | 2011-08-11 | Naohiko Morota | Switching power supply device |
| CN202978703U (en) * | 2012-05-08 | 2013-06-05 | 成都芯源系统有限公司 | Switching power supply circuit |
| CN203368317U (en) * | 2013-04-28 | 2013-12-25 | 矽恩微电子(厦门)有限公司 | High PFC constant current control device without loop compensation and voltage converter |
-
2014
- 2014-07-02 CN CN201410311591.4A patent/CN105245098B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1561570A (en) * | 2001-07-20 | 2005-01-05 | 皇家菲利浦电子有限公司 | Oscillating circuit, converter with such oscillating circuit, and preconditioner with such converter |
| US6788038B1 (en) * | 2003-01-29 | 2004-09-07 | National Semiconductor Corporation | Apparatus and method for deactivating an on-switch of a circuit for a variable time interval |
| CN1855680A (en) * | 2005-04-26 | 2006-11-01 | 美国芯源系统股份有限公司 | Controlling method of switching power supply and product using it |
| CN101677206A (en) * | 2008-09-15 | 2010-03-24 | 电力集成公司 | Method and apparatus to reduce line current harmonics from a power supply |
| JP2010183723A (en) * | 2009-02-05 | 2010-08-19 | Mitsumi Electric Co Ltd | Dc-dc converter and switching control circuit |
| US20110194316A1 (en) * | 2010-02-09 | 2011-08-11 | Naohiko Morota | Switching power supply device |
| CN202978703U (en) * | 2012-05-08 | 2013-06-05 | 成都芯源系统有限公司 | Switching power supply circuit |
| CN203368317U (en) * | 2013-04-28 | 2013-12-25 | 矽恩微电子(厦门)有限公司 | High PFC constant current control device without loop compensation and voltage converter |
Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107634654B (en) * | 2016-07-13 | 2019-08-27 | 光宝电子(广州)有限公司 | Resonance conversion device and its control method |
| CN107634654A (en) * | 2016-07-13 | 2018-01-26 | 光宝电子(广州)有限公司 | Resonance conversion device and its control method |
| CN107994760A (en) * | 2016-10-27 | 2018-05-04 | 上海儒竞电子科技有限公司 | A kind of pulse modulation method and system |
| CN107994760B (en) * | 2016-10-27 | 2019-06-25 | 上海儒竞电子科技有限公司 | A kind of pulse modulation method and system |
| CN106505860B (en) * | 2016-11-04 | 2019-05-28 | 深圳市华星光电技术有限公司 | A kind of output control method, output control system and liquid crystal display |
| CN106505860A (en) * | 2016-11-04 | 2017-03-15 | 深圳市华星光电技术有限公司 | A kind of output control method, output control system and liquid crystal display |
| CN106602861B (en) * | 2016-12-19 | 2019-07-12 | 深圳市华星光电技术有限公司 | Improve the control circuit of Active PFC transfer efficiency |
| CN106602861A (en) * | 2016-12-19 | 2017-04-26 | 深圳市华星光电技术有限公司 | Control circuit improving power factor correction conversion efficiency |
| CN107370366B (en) * | 2017-08-22 | 2024-04-23 | 瓴芯电子科技(无锡)有限公司 | Step-down DC-DC converter system |
| CN107370366A (en) * | 2017-08-22 | 2017-11-21 | 无锡瓴芯电子科技有限公司 | A kind of voltage-dropping type DC DC changer systems |
| WO2019062263A1 (en) * | 2017-09-27 | 2019-04-04 | 广州金升阳科技有限公司 | Control method for asymmetric half-bridge flyback circuit, and circuit |
| CN109660112A (en) * | 2017-10-11 | 2019-04-19 | 英飞凌科技股份有限公司 | The control of switching regulaor |
| CN110719095A (en) * | 2018-07-12 | 2020-01-21 | 浙江海利普电子科技有限公司 | Power supply circuit and method for monitoring state of load supplied by power supply circuit |
| CN110120204A (en) * | 2019-04-04 | 2019-08-13 | 惠科股份有限公司 | Driving method of power supply driving module, power supply driving module and display device |
| CN110120204B (en) * | 2019-04-04 | 2020-12-25 | 惠科股份有限公司 | Driving method of power supply driving module, power supply driving module and display device |
| CN112492722A (en) * | 2019-08-23 | 2021-03-12 | 圣邦微电子（北京）股份有限公司 | LED drive circuit and control circuit thereof |
| WO2021175002A1 (en) * | 2020-03-06 | 2021-09-10 | Shunzhu Tao | A resonant circuit converter and control method |
| CN113315380A (en) * | 2021-05-25 | 2021-08-27 | 上海晶丰明源半导体股份有限公司 | Switching power supply control circuit, system and control method |
| CN115189561A (en) * | 2022-06-22 | 2022-10-14 | 骏盈半导体(上海)有限公司 | CFT control circuit with adjustable frequency |
| CN117526717A (en) * | 2024-01-03 | 2024-02-06 | 杰华特微电子股份有限公司 | Frequency adjusting circuit and method for switching power supply and switching power supply |
| CN117526717B (en) * | 2024-01-03 | 2024-04-19 | 杰华特微电子股份有限公司 | Frequency adjusting circuit and method for switching power supply and switching power supply |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105245098B (en) | 2019-02-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105245098A (en) | Pulse frequency modulator for power supply converter and modulation method | |
| US10742122B2 (en) | Systems and methods for voltage control and current control of power conversion systems with multiple operation modes | |
| CN107248817B (en) | Quasi-resonance control switching circuit and method | |
| CN101728954B (en) | Control circuit for DC-DC converter and method thereof | |
| CN107546964B (en) | A kind of loop control system and control method of DC-DC converter | |
| CN103248207B (en) | Constant-current and constant-voltage fly-back converter based on primary side feedback | |
| CN103095135B (en) | Switch converter and slope compensation circuit thereof | |
| US9343979B2 (en) | Systems and methods for constant current control with primary-side sensing and regulation in various operation modes | |
| CN109004839B (en) | A control method for improving the dynamic response of switching power supply between heavy load and light load | |
| CN102237812B (en) | Primary side feedback (FB) switching power supply controller and switching power supply system | |
| CN111953185B (en) | ZVS (zero voltage switching) control method for active clamp flyback topology self-adaptive dead time | |
| CN110380628B (en) | Power conversion control chip and power adapter | |
| CN102810984B (en) | Switching power circuit | |
| CN102801305A (en) | Peak current signal generation circuit, switching power supply circuit and method thereof | |
| CN104756384A (en) | Switching regulator and control method thereof | |
| CN103066853A (en) | Control circuit, switching power supply and control method thereof | |
| CN104038048A (en) | Boost converter | |
| CN103151943A (en) | Dual-threshold control system and method for switch power supply | |
| CN212752105U (en) | Inductive current detection circuit and power converter | |
| CN104470158A (en) | Voltage-reduction structure LED driving circuit, and constant current driver and design method thereof | |
| CN111953186A (en) | Switching power supply control circuit | |
| CN203135724U (en) | Switch converter and slope compensation circuit thereof | |
| CN104716836A (en) | Control circuit and method for switching power converter | |
| CN103414323B (en) | Reduce the circuit of service time in current-control type switching regulators | |
| CN203206106U (en) | Power factor correction circuit and control circuit thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |