CN202340188U - Frequency jitter device and switching power supply thereof - Google Patents
Frequency jitter device and switching power supply thereof Download PDFInfo
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- CN202340188U CN202340188U CN 201120471134 CN201120471134U CN202340188U CN 202340188 U CN202340188 U CN 202340188U CN 201120471134 CN201120471134 CN 201120471134 CN 201120471134 U CN201120471134 U CN 201120471134U CN 202340188 U CN202340188 U CN 202340188U
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Abstract
The utility model discloses a frequency jitter device and a switching power supply thereof. The frequency jitter device comprises a control signal circuit, a voltage multi-path selection circuit, a saw-tooth wave generation circuit and an oscillating circuit, wherein the control signal circuit is used for controlling an oscillating frequency signal output by the oscillating circuit and generating a plurality of pulse output signals; the voltage multi-path selection circuit is controlled to select a corresponding voltage signal through the pulse output signals generated by the control signal circuit; the saw-tooth wave generation circuit is used for generating a saw-tooth wave signal; the oscillating circuit is used for comparing the voltage signal generated by the voltage multi-path selection circuit with saw-tooth wave generated by the saw-tooth wave generation circuit to obtain an oscillating frequency output signal; and the oscillating frequency is a frequency jitter output signal. By using the frequency jitter device and the switching power supply thereof, electromagnetic interference noise can be reduced, the cost is effectively reduced and the size of a switching power supply system is reduced.
Description
Technical field
The utility model relates to the frequency jitter technology, refers more particularly to the frequency jitter device of field of switch power.
Background technology
Because the switching frequency of Switching Power Supply voltage stabilizing circuit is increasingly high, it is more and more serious to cause circuit to produce electromagnetic interference.In order to control electromagnetic interference, stipulated the control criterion of emittance, so that guarantee can be owing to the phase mutual interference influences operate as normal between the various instruments.The method that actual employing reduces the Switching Power Supply electromagnetic interference is filtering, but this method certainly will increase the volume and the cost of switch power supply system.
Summary of the invention
The utility model is intended to solve the deficiency of prior art, and a kind of frequency jitter device that can suppress electromagnetic interference preferably is provided, and can reduce the volume and the cost of switch power supply system simultaneously effectively.
The utility model also provides a kind of method that produces frequency jitter.
The utility model also provides a kind of Switching Power Supply with frequency jitter device.
The method that the utility model also provides a kind of Switching Power Supply to regulate.
The frequency jitter device comprises control signal circuit, voltage multiplexer circuit, sawtooth wave generating circuit and oscillating circuit:
Said control signal circuit is controlled said control signal circuit to the oscillation frequency signal of said oscillating circuit output and is produced some pulse output signals;
Other a kind of implementation of said control signal circuit is that the said control signal circuit of an independent signal controlling produces some pulse output signals;
Said voltage multiplexer circuit is that some pulse output signals that said control signal circuit produces are selected the correspondent voltage signal through the said voltage multiplexer circuit of control;
Said sawtooth wave generating circuit produces sawtooth signal;
Said oscillating circuit is that sawtooth waveforms that the voltage signal that produces of said voltage multiplexer circuit and said sawtooth wave generating circuit produce compares and obtains frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
Said control signal circuit comprises counter, the frequency of oscillation output signal linkage counter of said oscillating circuit output, and counter carries out frequency division to frequency of oscillation output signal, produces pulse output signals;
Other a kind of implementation of the input of said control signal circuit is to connect a signal of the low-frequency oscillator output of design separately;
Said counter is connected in series by N frequency divider, and back one frequency divider carries out frequency division to the output of last frequency divider, and the output of each frequency divider produces some pulse output signals after making up through logical circuit.
Said voltage multiplexer circuit comprises N+1 nmos switch and N+4 resistance composition; The output signal of the grid linkage counter of said nmos switch, the number of nmos switch is consistent with the number of counter output signal; Said each nmos switch is made up of a NMOS, and the source electrode of NMOS links to each other with the drain electrode of the NMOS of vicinity, and grid connects the output of counter.
Said sawtooth wave generating circuit comprises a comparator, two current sources, an electric capacity, a switch; Positive termination first reference voltage of said comparator, the negative terminal of said comparator connects first current source, said electric capacity and said switch, the said switch of output termination of said comparator; Said first current source, one termination power, the negative terminal and the switch of the said electric capacity of another termination, said comparator; Said first current source of one termination of said electric capacity and said switch, other end ground connection; Said switch is controlled by comparator, a termination first current source of said switch, another termination second current source; The other end ground connection of said second current source.
Said oscillating circuit comprises two comparators and two NAND gate devices; The voltage output end of the said voltage multiplexer circuit of positive termination of first comparator, the negative terminal of first comparator connects the output of said sawtooth wave generating circuit, and first comparator output terminal connects the first input end of first NAND gate; The output of the said sawtooth wave generating circuit of positive termination of second comparator, the negative terminal of second comparator connects second reference voltage, and second comparator output terminal connects the first input end of second NAND gate; Second input of output termination first NAND gate of second NAND gate; The output of the second input termination, first NAND gate of second NAND gate; The signal of the output output of first NAND gate is exported frequency of oscillation output signal exactly, that is to say frequency jitter output signal.
Produce the method for frequency jitter, comprise the steps:
(1) frequency of oscillation output signal is deciphered, or the low-frequency oscillator of design separately output signal deciphers, produce some pulse output signals;
(2) the low-frequency oscillator output signal of said frequency of oscillation output signal or design is separately selected a voltage signal through control voltage multiplexer circuit;
(3) said sawtooth wave generating circuit produces sawtooth signal;
(4) sawtooth signal of the voltage signal of said (2) generation and said (3) generation compares and obtains frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
Said frequency jitter output signal repeats the frequency jitter output signal in aforementioned cycle after several cycles.
Said step (1) implementation method is: said pulse output signals is carried out frequency division through frequency divider to frequency of oscillation output signal and is produced.
Said frequency divider can be for a plurality of, each frequency divider serial connection, and back one frequency divider carries out frequency division to the output of last frequency divider, and the output of each frequency divider produces some pulse output signals after making up through logical circuit.
Said step (2) implementation method is: said voltage multiplexer circuit comprises N+1 nmos switch and N+4 resistance composition; The output signal of the grid linkage counter of said nmos switch, the number of nmos switch is consistent with the number of counter output signal; Said each nmos switch is made up of a NMOS, and the source electrode of NMOS links to each other with the drain electrode of the NMOS of vicinity, and grid connects the output of counter.The pulse output signals that said control signal circuit produces is controlled the NMOS conducting of said voltage multiplexer circuit, produces voltage signal through dividing potential drop then.
Said step (3) implementation method is: said sawtooth wave generating circuit comprises a comparator, two current sources, an electric capacity, a switch; Positive termination first reference voltage of said comparator, the negative terminal of said comparator connects first current source, said electric capacity and said switch, the said switch of output termination of said comparator; Said first current source, one termination power, the negative terminal and the switch of the said electric capacity of another termination, said comparator; Said first current source of one termination of said electric capacity and said switch, other end ground connection; Said switch is controlled by comparator, a termination first current source of said switch, another termination second current source; The other end ground connection of said second current source.First current source charges to electric capacity; When first reference voltage of the positive termination that reaches comparator; Comparator is exported the control switch that overturns; Then electric capacity discharges through second current source, and comparator overturns again when discharge makes voltage on the electric capacity drop to first reference voltage, repeats aforementioned a series of sawtooth signals that produce afterwards.
Said step (4) implementation method is: said oscillating circuit comprises two comparators and two NAND gate devices; The voltage output end of the said voltage multiplexer circuit of positive termination of first comparator, the negative terminal of first comparator connects the output of said sawtooth wave generating circuit, and first comparator output terminal connects the first input end of first NAND gate; The output of the said sawtooth wave generating circuit of positive termination of second comparator, the negative terminal of second comparator connects second reference voltage, and second comparator output terminal connects the first input end of second NAND gate; Second input of output termination first NAND gate of second NAND gate; The output of the second input termination, first NAND gate of second NAND gate; The signal of the output output of first NAND gate is exported frequency of oscillation output signal exactly, that is to say frequency jitter output signal.
Utilize the Switching Power Supply of the frequency jitter device realization of the utility model, comprise transformer, power tube, switch regulating circuit and frequency jitter device:
Said transformer, its main coil one end connect the direct voltage input, and secondary coil one end connects diode, and wherein the other end of diode connects the direct voltage output plus terminal, and the secondary coil other end connects direct voltage output negative terminal;
Said power tube, its first end connects the other end of the main coil of said transformer, and second end connects ground, and the 3rd end connects the switch regulating circuit;
Said switch regulating circuit; The feedback signal of described frequency jitter signal and transformer output is controlled described switch regulating circuit by-pass cock signal; The frequency of described frequency jitter Signal Regulation switching signal, the duty ratio of described feedback signal by-pass cock signal;
Said frequency jitter device comprises:
The control signal circuit is deciphered frequency of oscillation output signal, or the low-frequency oscillator of design separately output signal deciphers, and produces some pulse output signals;
The voltage multiplexer circuit, the NMOS conducting of the pulse output signals control voltage multiplexer circuit that the control signal circuit produces produces voltage signal through dividing potential drop then;
Sawtooth wave generating circuit produces sawtooth signal;
Oscillating circuit produces frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
The method that Switching Power Supply is regulated comprises:
(1) frequency of oscillation output signal is deciphered, or the low-frequency oscillator of design separately output signal deciphers, produce some pulse output signals;
(2) the low-frequency oscillator output signal of said frequency of oscillation output signal or design is separately selected a voltage signal through control voltage multiplexer circuit;
(3) said sawtooth wave generating circuit produces sawtooth signal;
(4) sawtooth signal of the voltage signal of said (2) generation and said (3) generation compares and obtains frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
(5) frequency jitter Signal-controlled switch regulating circuit is regulated the output of the power tube that is connected to the transformer main coil, thereby regulates direct voltage output.
Utilize frequency jitter device that the utility model provides, produce switching frequency that the method for frequency jitter obtains a wide frequency range; Make electromagnetic interference energy dissipation that the electromagnetic interference device measuring arrives beyond bandwidth; Switching frequency shake back and forth reduces electromagnetic interference noise; The frequency jitter that realizes with traditional filtering method is compared and has been reduced cost, has reduced the volume of switch power supply system simultaneously.
Description of drawings
Fig. 1 is the structure chart of the frequency jitter device of the utility model.
Fig. 2 has the circuit diagram of N position for the counter of the utility model Fig. 1.
Fig. 3 has 4 circuit diagram for the counter of the utility model Fig. 1.
Fig. 4 is the change in voltage figure of the utility model voltage multiplexer circuit.
The sawtooth waveforms output signal diagram that Fig. 5 produces for the utility model sawtooth wave generating circuit.
Fig. 6 is the frequency jitter output signal diagram that the utility model frequency jitter device produces.
Fig. 7 is a Switching Power Supply of utilizing the frequency jitter device realization of the utility model.
Embodiment
Below in conjunction with accompanying drawing the utility model content is further specified.
As shown in Figure 1, the structure chart for the frequency jitter device of the utility model comprises control signal circuit 11, voltage multiplexer circuit 12, sawtooth wave generating circuit 13 and oscillating circuit 14:
Said control signal circuit 11 is to the some pulse output signals 21 of said control signal circuit 11 generations of oscillation frequency signal 24 controls of said oscillating circuit 14 outputs;
Other a kind of implementation of said control signal circuit 11 is that the said control signal circuit of an independent signal controlling produces some pulse output signals;
Said voltage multiplexer circuit 12 is that some pulse output signals 21 that said control signal circuit 11 produces are selected correspondent voltage signal 22 through the said voltage multiplexer circuit 12 of control;
Said sawtooth wave generating circuit 13 produces sawtooth signal 23;
[0058] said oscillating circuit 14 produces frequency of oscillation output signal 24; Said frequency of oscillation output signal 24 is exactly a frequency jitter output signal.
Said control signal circuit 11 comprises counter, frequency of oscillation output signal 24 linkage counters of said oscillating circuit 14 outputs, and counter carries out frequency division to frequency of oscillation output signal, produces pulse output signals 21;
Other a kind of implementation of the input of said control signal circuit 11 is to connect a signal of the low-frequency oscillator output of design separately;
As shown in Figure 2, the circuit diagram of N position is arranged for the counter of the utility model Fig. 1.
As shown in Figure 3,4 circuit diagram is arranged for the counter of the utility model Fig. 1.
Said voltage multiplexer circuit 12 comprise N+1 nmos switch N0, N1, N2, N3, N4 ..., Nn and N+4 resistance R 21, R22, R23, R10, R11, R12, R13, R14 ..., R1n forms; The output signal 21 of the grid linkage counter of said nmos switch, the number of nmos switch is consistent with the number of counter output signal; Said each nmos switch is made up of a NMOS, and the source electrode of NMOS links to each other with the drain electrode of the NMOS of vicinity, and grid connects the output of counter.
Said sawtooth wave generating circuit 13 comprises a comparator 43, two current source I1 and I2, capacitor C 1, a K switch 1; Positive termination first reference voltage 45 of said comparator 43, the negative terminal of said comparator 43 connects the first current source I1, said capacitor C 1 and said K switch 1, the said K switch 1 of the output termination of said comparator 43; The said first current source I1, one termination power VCC, the negative terminal and the K switch 1 of the said capacitor C of another termination 1, said comparator 43; Said first current source I1 of one termination of said capacitor C 1 and said K switch 1, other end ground connection; Said K switch 1 receives comparator 43 controls, a termination first current source I1 of said K switch 1, another termination second current source I2; The other end ground connection of the said second current source I2.
Said oscillating circuit 14 comprises two comparators 52 and 53 and two NAND gate devices 54 and 57; Output 23, the first comparators 53 outputs 56 that the negative terminal of voltage output end 22, the first comparators 53 of the said voltage multiplexer circuit 12 of positive termination of first comparator 53 connects said sawtooth wave generating circuit 13 connect the first input end of first NAND gate 57; The negative terminal of output 23, the second comparators 52 of the said sawtooth wave generating circuit 13 of positive termination of second comparator 52 connects the first input end that second reference voltage, 51, the second comparators, 52 outputs 55 connect second NAND gate 54; Second input of output termination first NAND gate 57 of second NAND gate 54; The output 24 of the second input termination, first NAND gate 57 of second NAND gate 54; The signal 24 of the output output of first NAND gate 57 is exactly to export frequency of oscillation output signal, that is to say frequency jitter output signal.
Produce the method for frequency jitter, comprise the steps:
(1) frequency of oscillation output signal 24 is deciphered, or the low-frequency oscillator of design separately output signal deciphers, produce some pulse output signals 21;
(2) the low-frequency oscillator output signal of said frequency of oscillation output signal 24 or design is separately selected a voltage signal 22 through control voltage multiplexer circuit 12;
As shown in Figure 4, be the change in voltage figure of the utility model voltage multiplexer circuit.
(3) said sawtooth wave generating circuit 13 produces sawtooth signal 23;
As shown in Figure 5, be the sawtooth waveforms output signal diagram of the utility model sawtooth wave generating circuit generation.
(4) sawtooth signal 23 of the voltage signal 22 of said (2) generation and said (3) generation compares and obtains frequency of oscillation output signal 24, and this frequency of oscillation is exactly a frequency jitter output signal.
As shown in Figure 6, be the frequency jitter output signal diagram of the utility model frequency jitter device generation.
Said frequency jitter output signal repeats the frequency jitter output signal in aforementioned cycle after several cycles.
Said step (1) implementation method is: said pulse output signals is carried out frequency division through frequency divider to frequency of oscillation output signal and is produced.
Said step (2) implementation method is: said voltage multiplexer circuit 12 comprise N+1 nmos switch N0, N1, N2, N3, N4 ..., Nn and N+4 resistance R 21, R22, R23, R10, R11, R12, R13, R14 ..., R1n forms; The output signal 21 of the grid linkage counter of said nmos switch, the number of nmos switch is consistent with the number of counter output signal; Said each nmos switch is made up of a NMOS, and the source electrode of NMOS links to each other with the drain electrode of the NMOS of vicinity, and grid connects the output of counter.The pulse output signals that said control signal circuit produces is controlled the NMOS conducting of said voltage multiplexer circuit, produces voltage signal through dividing potential drop then.
Said step (3) implementation method is: said sawtooth wave generating circuit 13 comprises a comparator 43, two current source I1 and I2, capacitor C 1, a K switch 1; Positive termination first reference voltage 45 of said comparator 43, the negative terminal of said comparator 43 connects the first current source I1, said capacitor C 1 and said K switch 1, the said K switch 1 of the output termination of said comparator 43; The said first current source I1, one termination power VCC, the negative terminal and the K switch 1 of the said capacitor C of another termination 1, said comparator 43; Said first current source I1 of one termination of said capacitor C 1 and said K switch 1, other end ground connection; Said K switch 1 receives comparator 43 controls, a termination first current source I1 of said K switch 1, another termination second current source I2; The other end ground connection of the said second current source I2.The first current source I1 charges to capacitor C 1; When first reference voltage 45 of the positive termination that reaches comparator 43; The comparator output 44 control switch K1 that overturns; Then capacitor C 1 is discharged through the second current source I2, and comparator 43 overturns again when discharge makes voltage on the capacitor C 1 drop to first reference voltage 45, repeats aforementioned a series of sawtooth signals that produce afterwards.
Said step (4) implementation method is: said oscillating circuit 14 comprises two comparators 52 and 53 and two NAND gate devices 54 and 57; Output 23, the first comparators 53 outputs 56 that the negative terminal of voltage output end 22, the first comparators 53 of the said voltage multiplexer circuit 12 of positive termination of first comparator 53 connects said sawtooth wave generating circuit 13 connect the first input end of first NAND gate 57; The negative terminal of output 23, the second comparators 52 of the said sawtooth wave generating circuit 13 of positive termination of second comparator 52 connects the first input end that second reference voltage, 51, the second comparators, 52 outputs 55 connect second NAND gate 54; Second input of output termination first NAND gate 57 of second NAND gate 54; The output 24 of the second input termination, first NAND gate 57 of second NAND gate 54; The signal 24 of the output output of first NAND gate 57 is exactly to export frequency of oscillation output signal, that is to say frequency jitter output signal.The sawtooth signal 23 of voltage signal 22 that said voltage multiplexer circuit produces and said sawtooth wave generating circuit 13 generations compares and obtains frequency of oscillation output signal 24, and this frequency of oscillation is exactly a frequency jitter output signal.
As shown in Figure 7, the frequency jitter device is applied in Switching Power Supply.Dc voltage input end 68 connects the main coil 69 of transformer, and main coil 69 two ends connect resistance 67, electric capacity 65 and the diode 66 of series connection.Transformer secondary coil 71 1 ends connect diode 72, and the output of said diode 72 connects an end of electric capacity 74, also is direct voltage output plus terminal 73.The other end of said electric capacity 74 is a direct voltage output negative terminal; Said transformer secondary coil 71 other ends connect said direct voltage output negative terminal.Voltage stabilizing didoe 76 1 ends are connected to ground, and the other end is connected to input light-emitting diode one end of photoelectric coupling circuit 75, and the said light-emitting diode other end connects said direct voltage output plus terminal 73.The collector electrode of the output triode of said photoelectric coupling circuit 75 connects feedback signal 81, and said collector current is regulated the voltage of said feedback signal, the voltage cut-out regulating circuit 63 by-pass cock signals 82 of said feedback signal.The transformer main coil other end connects power tube.The other end of said power tube 64 connects ground, and the 3rd end connects switching signal.Said switch regulating circuit driving power pipe is regulated direct voltage output.Frequency jitter output signal 23 control switch regulating circuits produce the switching frequency signal, and the voltage cut-out regulating circuit of said feedback signal produces the duty cycle of switching signal.
Said frequency jitter output signal is produced by the frequency jitter device, and said frequency jitter device comprises:
The control signal circuit is deciphered frequency of oscillation output signal, or the low-frequency oscillator of design separately output signal deciphers, and produces some pulse output signals;
The voltage multiplexer circuit, the NMOS conducting of the pulse output signals control voltage multiplexer circuit that the control signal circuit produces produces voltage signal through dividing potential drop then;
Sawtooth wave generating circuit produces sawtooth signal;
Oscillating circuit produces frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
Produce the method for frequency jitter, comprise the steps:
(1) frequency of oscillation output signal is deciphered, or the low-frequency oscillator of design separately output signal deciphers, produce some pulse output signals;
(2) the low-frequency oscillator output signal of said frequency of oscillation output signal or design is separately selected a voltage signal through control voltage multiplexer circuit;
(3) said sawtooth wave generating circuit produces sawtooth signal;
(4) sawtooth signal of the voltage signal of said (2) generation and said (3) generation compares and obtains frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
Said frequency jitter output signal repeats the frequency jitter output signal in aforementioned cycle after several cycles.
The method that Switching Power Supply is regulated comprises:
(1) frequency of oscillation output signal is deciphered, or the low-frequency oscillator of design separately output signal deciphers, produce some pulse output signals;
(2) the low-frequency oscillator output signal of said frequency of oscillation output signal or design is separately selected a voltage signal through control voltage multiplexer circuit;
(3) said sawtooth wave generating circuit produces sawtooth signal;
(4) sawtooth signal of the voltage signal of said (2) generation and said (3) generation compares and obtains frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
(5) frequency jitter Signal-controlled switch regulating circuit is regulated the output of the power tube that is connected to the transformer main coil, thereby regulates direct voltage output.
The utility model discloses the frequency jitter apparatus and method that are used for Switching Power Supply, and illustrate and describe the embodiment and the effect of the utility model.What should be understood that is: the foregoing description is the explanation to the utility model; Rather than to the restriction of the utility model; Any utility model that does not exceed in the utility model connotation scope is created; Include but not limited to the local structure of circuit change, to the replacement of the type or the model of components and parts, and the replacement of other unsubstantialities or modification all fall within the utility model protection range.
Claims (6)
1. frequency jitter device is characterized in that comprising:
The control signal circuit is controlled said control signal circuit to the oscillation frequency signal of said oscillating circuit output and is produced some pulse output signals;
The voltage multiplexer circuit, some pulse output signals that said control signal circuit produces are selected the correspondent voltage signal through the said voltage multiplexer circuit of control;
Sawtooth wave generating circuit produces sawtooth signal;
Oscillating circuit, the sawtooth waveforms that voltage signal that said voltage multiplexer circuit produces and said sawtooth wave generating circuit produce compare and obtain frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
2. frequency jitter device according to claim 1 is characterized in that the control signal circuit comprises counter, the frequency of oscillation output signal linkage counter of said oscillating circuit output, and counter carries out frequency division to frequency of oscillation output signal, produces pulse output signals.
3. frequency jitter device according to claim 1 is characterized in that the voltage multiplexer circuit comprises that N+1 nmos switch and N+4 resistance forms; The output signal of the grid linkage counter of said nmos switch, the number of nmos switch is consistent with the number of counter output signal; Said each nmos switch is made up of a NMOS, and the source electrode of NMOS links to each other with the drain electrode of the NMOS of vicinity, and grid connects the output of counter.
4. frequency jitter device according to claim 1 is characterized in that sawtooth wave generating circuit comprises a comparator, two current sources, an electric capacity, a switch; Positive termination first reference voltage of said comparator, the negative terminal of said comparator connects first current source, said electric capacity and said switch, the said switch of output termination of said comparator; Said first current source, one termination power, the negative terminal and the switch of the said electric capacity of another termination, said comparator; Said first current source of one termination of said electric capacity and said switch, other end ground connection; Said switch is controlled by comparator, a termination first current source of said switch, another termination second current source; The other end ground connection of said second current source.
5. frequency jitter device according to claim 1 is characterized in that oscillating circuit comprises two comparators and two NAND gate devices; The voltage output end of the said voltage multiplexer circuit of positive termination of first comparator, the negative terminal of first comparator connects the output of said sawtooth wave generating circuit, and first comparator output terminal connects the first input end of first NAND gate; The output of the said sawtooth wave generating circuit of positive termination of second comparator, the negative terminal of second comparator connects second reference voltage, and second comparator output terminal connects the first input end of second NAND gate; Second input of output termination first NAND gate of second NAND gate; The output of the second input termination, first NAND gate of second NAND gate; The signal of the output output of first NAND gate is exported frequency of oscillation output signal exactly, that is to say frequency jitter output signal.
6. Switching Power Supply is characterized in that comprising;
Transformer, its main coil one end connect the direct voltage input, and secondary coil one end connects diode, and wherein the other end of diode connects the direct voltage output plus terminal, and the secondary coil other end connects direct voltage output negative terminal;
Power tube, its first end connects the other end of the main coil of said transformer, and second end connects ground, and the 3rd end connects the switch regulating circuit;
The switch regulating circuit; The feedback signal of described frequency jitter signal and transformer output is controlled described switch regulating circuit by-pass cock signal; The frequency of described frequency jitter Signal Regulation switching signal, the duty ratio of described feedback signal by-pass cock signal;
The frequency jitter device comprises:
The control signal circuit is deciphered frequency of oscillation output signal, or the low-frequency oscillator of design separately output signal deciphers, and produces some pulse output signals;
The voltage multiplexer circuit, the NMOS conducting of the pulse output signals control voltage multiplexer circuit that the control signal circuit produces produces voltage signal through dividing potential drop then;
Sawtooth wave generating circuit produces sawtooth signal;
Oscillating circuit produces frequency of oscillation output signal, and this frequency of oscillation is exactly a frequency jitter output signal.
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| CN 201120471134 CN202340188U (en) | 2011-11-21 | 2011-11-21 | Frequency jitter device and switching power supply thereof |
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| CN 201120471134 CN202340188U (en) | 2011-11-21 | 2011-11-21 | Frequency jitter device and switching power supply thereof |
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| CN202340188U true CN202340188U (en) | 2012-07-18 |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103001491A (en) * | 2012-11-19 | 2013-03-27 | 电子科技大学 | Digital frequency jitter circuit |
| CN103259415A (en) * | 2013-05-14 | 2013-08-21 | 辉芒微电子（深圳）有限公司 | Constant current switching power supply and constant current controller thereof |
| CN104104222A (en) * | 2013-04-03 | 2014-10-15 | 富士电机株式会社 | Switching power supply device |
| CN104753499A (en) * | 2015-04-17 | 2015-07-01 | 上海华虹宏力半导体制造有限公司 | Duty ratio calibrating circuit |
| CN113422507A (en) * | 2021-06-28 | 2021-09-21 | 思瑞浦微电子科技（苏州）股份有限公司 | Jitter frequency control circuit and switching power supply |
| CN113489473A (en) * | 2021-07-23 | 2021-10-08 | 星宸科技股份有限公司 | Frequency generating device and frequency generating method |
| CN115085515A (en) * | 2022-08-22 | 2022-09-20 | 成都动芯微电子有限公司 | Novel output power adjustable circuit |
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- 2011-11-21 CN CN 201120471134 patent/CN202340188U/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103001491A (en) * | 2012-11-19 | 2013-03-27 | 电子科技大学 | Digital frequency jitter circuit |
| CN104104222A (en) * | 2013-04-03 | 2014-10-15 | 富士电机株式会社 | Switching power supply device |
| CN104104222B (en) * | 2013-04-03 | 2018-04-13 | 富士电机株式会社 | Switching power unit |
| CN103259415A (en) * | 2013-05-14 | 2013-08-21 | 辉芒微电子（深圳）有限公司 | Constant current switching power supply and constant current controller thereof |
| CN103259415B (en) * | 2013-05-14 | 2016-03-02 | 辉芒微电子（深圳）有限公司 | Constant-current switch power source and constant-current controller thereof |
| CN104753499A (en) * | 2015-04-17 | 2015-07-01 | 上海华虹宏力半导体制造有限公司 | Duty ratio calibrating circuit |
| CN104753499B (en) * | 2015-04-17 | 2017-05-24 | 上海华虹宏力半导体制造有限公司 | Duty ratio calibrating circuit |
| CN113422507A (en) * | 2021-06-28 | 2021-09-21 | 思瑞浦微电子科技（苏州）股份有限公司 | Jitter frequency control circuit and switching power supply |
| CN113422507B (en) * | 2021-06-28 | 2022-08-02 | 思瑞浦微电子科技（苏州）股份有限公司 | Jitter frequency control circuit and switching power supply |
| CN113489473A (en) * | 2021-07-23 | 2021-10-08 | 星宸科技股份有限公司 | Frequency generating device and frequency generating method |
| CN113489473B (en) * | 2021-07-23 | 2023-10-31 | 星宸科技股份有限公司 | Frequency generation device and frequency generation method |
| CN115085515A (en) * | 2022-08-22 | 2022-09-20 | 成都动芯微电子有限公司 | Novel output power adjustable circuit |
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