CN212752124U - Control circuit of switch circuit and switch circuit - Google Patents
Control circuit of switch circuit and switch circuit Download PDFInfo
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- CN212752124U CN212752124U CN202021414036.1U CN202021414036U CN212752124U CN 212752124 U CN212752124 U CN 212752124U CN 202021414036 U CN202021414036 U CN 202021414036U CN 212752124 U CN212752124 U CN 212752124U
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Abstract
The utility model discloses a control circuit and a switch circuit of a switch circuit, wherein a first circuit samples the output voltage and the output current of the switch circuit, and the output end of the first circuit is connected to the output feedback end of the switch circuit; the output feedback end of the switch circuit is the input end of the second circuit; the first circuit controls the output voltage and the output upper limit current of the switch circuit; the second circuit comprises all or part of the power circuit of the switch circuit, the drive circuit of the switch circuit and the logic control circuit.
Description
Technical Field
The utility model relates to a power electronic technology field, concretely relates to switch circuit's control circuit and switch circuit.
Background
In the switch circuit, it is conventionally done to detect the output voltage through the feedback pin FB, so as to stabilize the output voltage of the switch circuit. Generally, the output current limitation of the switch circuit cannot be realized through the feedback pin FB, and an additional pin is needed to sample the output current and feed the output current back to the switch circuit to realize the current limitation.
When the switching circuit is provided with the protocol chip and the power chip, the power chip controls the output voltage and the output current limit of a single circuit of the switch, and the protocol chip cannot control the output voltage and the output current limit of the switching circuit. The power chip is required to have an output current limiting function, and a communication module is required to be arranged between the power chip and the protocol chip. The existing scheme increases the design complexity and cost of the power supply chip, and the compatibility between the power supply chip and the protocol chip is poor.
SUMMERY OF THE UTILITY MODEL
In view of this, an object of the present invention is to provide a control circuit of a switch circuit and a switch circuit, so as to solve the problem that the output current limitation of the switch circuit cannot be realized through the feedback pin FB in the prior art.
The technical solution of the present invention is to provide a control method of a switch circuit, wherein a first circuit samples output voltage and output current of the switch circuit, and an output end of the first circuit is connected to an output feedback end of the switch circuit; the output feedback end of the switch circuit is the input end of the second circuit; the first circuit controls the output voltage and the output upper limit current of the switch circuit;
the second circuit comprises all or part of the power circuit of the switch circuit, the drive circuit of the switch circuit and the logic control circuit.
Optionally, the first circuit includes a first transistor and a second operational amplifier, and the first circuit samples the output current of the switch circuit and a current-limiting reference value, and obtains a current-limiting compensation voltage through operational amplification; the current-limiting compensation voltage is connected to a control electrode of the first transistor, a drain electrode of the first transistor is connected with the output voltage of the switch circuit, and a source electrode of the first transistor is connected to a first end and an output end of the second operational amplifier; the output voltage of the switching circuit is connected to the second end of the second operational amplifier through resistance voltage division; and the output end of the second operational amplifier is the output end of the first circuit.
Optionally, the output terminal of the first circuit is connected to the output feedback terminal of the switching circuit through a voltage dividing resistor.
Optionally, the first circuit is a first chip; the second circuit is a second chip.
Optionally, the switching circuit is a dc-to-dc circuit, or an ac-to-dc circuit.
The utility model also provides a control circuit of the switch circuit, the first circuit samples the output voltage and the output current of the switch circuit, the output end of the first circuit is connected to the output feedback end of the switch circuit; the output feedback end of the switch circuit is the input end of the second circuit; the first circuit controls the output voltage and the output upper limit current of the switch circuit;
the second circuit comprises all or part of the power circuit of the switch circuit, the drive circuit of the switch circuit and the logic control circuit.
Optionally, the first circuit includes a first transistor and a second operational amplifier, and the first circuit samples the output current of the switch circuit and a current-limiting reference value, and obtains a current-limiting compensation voltage through operational amplification; the current-limiting compensation voltage is connected to a control electrode of the first transistor, a drain electrode of the first transistor is connected with the output voltage of the switch circuit, and a source electrode of the first transistor is connected to a first end and an output end of the second operational amplifier; the output voltage of the switching circuit is connected to the second end of the second operational amplifier through resistance voltage division; and the output end of the second operational amplifier is the output end of the first circuit.
Optionally, the first circuit further includes a first operational amplifier, and the first operational amplifier obtains the current-limiting compensation voltage by performing operational amplification on an output current sampling value and a current-limiting reference value of the switching circuit.
Optionally, the first circuit is a first chip; the second circuit is a second chip.
The utility model discloses a further technical solution is, provides a switch circuit.
Adopt the utility model discloses a circuit structure and method, compared with the prior art, have following advantage: through the output feedback end of the switch circuit, constant voltage and current limitation can be realized. When the protocol chip and the power supply chip are arranged in the switch circuit, the current limiting function and the constant voltage function are arranged in the protocol chip, so that the function of the power supply chip is simplified, and the conventional power supply chip can be flexibly matched.
Drawings
Fig. 1 is a schematic connection diagram of a first circuit and a second circuit according to the present invention;
fig. 2 is a schematic diagram of a first circuit connected to a second circuit through a voltage dividing resistor according to the present invention;
FIG. 3 is a schematic diagram of the connection between the first circuit and the second circuit of the present invention when the switch circuit is a BUCK circuit;
fig. 4 is a schematic diagram of the connection between the first circuit and the second circuit according to the present invention when the switch circuit is a BOOST circuit;
fig. 5 is a schematic diagram of an embodiment of a first circuit 200 according to the present invention.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to only these embodiments. The present invention covers any alternatives, modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.
In the following description of the preferred embodiments of the present invention, specific details are set forth in order to provide a thorough understanding of the present invention, and it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.
The invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are simplified and in non-precise proportion, and are only used for the purpose of conveniently and clearly assisting in explaining the embodiments of the present invention.
The utility model provides a control method of a switch circuit, please refer to fig. 1, a first circuit 200 samples the output voltage and the output current of the switch circuit, the output end of the first circuit 200 is connected to the output feedback end FB of the switch circuit; an output feedback end FB of the switch circuit is an input end of the second circuit; the first circuit controls the output voltage and the output upper limit current of the switch circuit; the second circuit comprises all or part of the power circuit of the switch circuit, the drive circuit of the switch circuit and the logic control circuit. Referring to fig. 1, the first circuit samples the output voltage VCC and the output current of the switch circuit, and the second circuit receives the output feedback terminal FB voltage of the first circuit 200 and controls the output voltage and the output upper limit current of the switch circuit according to the output feedback terminal FB. Referring to fig. 2, the output terminal VCTRL of the first circuit 200 is divided by voltage dividing resistors RFB1 and RFB2, and the common terminal of the voltage dividing resistors RFB1 and RFB2 is the output feedback terminal of the switch circuit and is the input terminal of the second circuit.
In one embodiment, the first circuit 200 is a first chip; the second circuit is a second chip.
In one embodiment, the first chip is a DCDC chip and the second chip is a protocol chip. Constant current and constant voltage functions are implemented in the protocol chip, so that the functions of the DCDC chip are simplified, and the conventional DCDC chip can be flexibly matched.
Referring to fig. 3, when the switch circuit is a BUCK circuit, the connection between the first circuit and the second circuit is schematically illustrated. When the second circuit is a DCDC chip, the second circuit comprises a logic control circuit, a driving circuit and a power tube. The logic control circuit receives the voltage of the output feedback end and performs operational amplification with the reference voltage to obtain a compensation voltage COMP, the logic control circuit adjusts a switching signal according to the compensation voltage, and the driving circuit receives the switching signal and drives the power tube. The above is merely an example of one control method of the second circuit, and is not limited to the control method described above. Referring to fig. 4, when the switch circuit is a BOOST circuit, the connection between the first circuit and the second circuit is schematically illustrated.
Referring to fig. 5, the first circuit 200 includes a first transistor M201 and a second operational amplifier 202, and the first circuit 200 samples an output current of the switching circuit and obtains a current-limiting compensation voltage CCCOMP by operational amplification with a current-limiting reference value; the current-limiting compensation voltage CCCOMP is connected to the control electrode of the first transistor M201, the drain of the first transistor is connected to the output voltage VCC of the switching circuit, and the source of the first transistor M201 is connected to the first end and the output end of the second operational amplifier 202; the output voltage VCC of the switch circuit is connected to the second end of the second operational amplifier through resistance voltage division; the output end of the second operational amplifier is the output end VCRTL of the first circuit.
In one embodiment, the first circuit further includes a first operational amplifier 201, and the first operational amplifier 201 obtains the current-limiting compensation voltage CCCOMP by operational amplification of the output current sampling value IS of the switching circuit and the current-limiting reference value CCref.
In one embodiment, please refer to fig. 2, the output terminal VCC of the first circuit is connected to the output feedback terminal FB of the switch circuit through the voltage dividing resistors RFB1 and RFB 2. Since the output voltage VCC of the switching circuit is connected to the operational amplifier 202 through the voltage dividing resistors R201, R202, the output voltage VCTRL of the operational amplifier 202 is equal to the voltage of the output voltage after voltage division. When the system enters a steady state, the output feedback terminal FB of the second circuit is equal to the reference voltage VREF. When the first circuit is a first chip and the second circuit is a second chip, generally R201 and R202 are fixed resistors, and the output voltage is set by adjusting the voltage dividing resistors RFB1 and RFB 2.
The switch circuit is a direct current to direct current conversion circuit, such as a BUCK circuit, a BOOST circuit, a BUCK BOOST circuit, etc., or an alternating current to direct current conversion circuit.
The utility model also provides a control circuit of the switch circuit, the first circuit samples the output voltage and the output current of the switch circuit, the output end of the first circuit is connected to the output feedback end of the switch circuit; the output feedback end of the switch circuit is the input end of the second circuit; the first circuit controls the output voltage and the output upper limit current of the switch circuit;
the second circuit comprises all or part of the power circuit of the switch circuit, the drive circuit of the switch circuit and the logic control circuit.
In one embodiment, the first circuit comprises a first transistor and a second operational amplifier, the first circuit samples the output current of the switch circuit, and the current-limiting reference value is subjected to operational amplification to obtain a current-limiting compensation voltage; the current-limiting compensation voltage is connected to a control electrode of the first transistor, a drain electrode of the first transistor is connected with the output voltage of the switch circuit, and a source electrode of the first transistor is connected to a first end and an output end of the second operational amplifier; the output voltage of the switching circuit is connected to the second end of the second operational amplifier through resistance voltage division; and the output end of the second operational amplifier is the output end of the first circuit.
In one embodiment, the first circuit further includes a first operational amplifier, and the first operational amplifier obtains the current-limiting compensation voltage by operational amplification of an output current sampling value of the switching circuit and a current-limiting reference value.
In one embodiment, the first circuit is a first chip; the second circuit is a second chip.
Another technical solution of the present invention is to provide a switching circuit, including the control method or the control circuit of the above switching circuit.
Although the embodiments have been described and illustrated separately, it will be apparent to those skilled in the art that some common techniques may be substituted and integrated between the embodiments, and reference may be made to one of the embodiments not explicitly described, or to another embodiment described.
The above-described embodiments do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the above-described embodiments should be included in the protection scope of the technical solution.
Claims (5)
1. A control circuit for a switching circuit, characterized by: the output end of the first circuit is connected to the output feedback end of the switch circuit; the output feedback end of the switch circuit is the input end of the second circuit; the first circuit controls the output voltage and the output upper limit current of the switch circuit;
the second circuit comprises all or part of the power circuit of the switch circuit, the drive circuit of the switch circuit and the logic control circuit.
2. The control circuit of claim 1, wherein: the first circuit comprises a first transistor and a second operational amplifier, the output current of the sampling switch circuit of the first circuit and the current-limiting reference value are subjected to operational amplification to obtain current-limiting compensation voltage; the current-limiting compensation voltage is connected to a control electrode of the first transistor, a drain electrode of the first transistor is connected with the output voltage of the switch circuit, and a source electrode of the first transistor is connected to a first end and an output end of the second operational amplifier; the output voltage of the switching circuit is connected to the second end of the second operational amplifier through resistance voltage division; and the output end of the second operational amplifier is the output end of the first circuit.
3. The control circuit of claim 2, wherein: the first circuit further comprises a first operational amplifier, and the first operational amplifier obtains the current-limiting compensation voltage by operational amplification of an output current sampling value and a current-limiting reference value of the switching circuit.
4. The control circuit of claim 1, wherein: the first circuit is a first chip; the second circuit is a second chip.
5. A switching circuit, characterized by: comprising a control circuit according to any of claims 1-4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021414036.1U CN212752124U (en) | 2020-07-17 | 2020-07-17 | Control circuit of switch circuit and switch circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021414036.1U CN212752124U (en) | 2020-07-17 | 2020-07-17 | Control circuit of switch circuit and switch circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212752124U true CN212752124U (en) | 2021-03-19 |
Family
ID=75036819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021414036.1U Active CN212752124U (en) | 2020-07-17 | 2020-07-17 | Control circuit of switch circuit and switch circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212752124U (en) |
-
2020
- 2020-07-17 CN CN202021414036.1U patent/CN212752124U/en active Active
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Patentee after: Jiehuate Microelectronics Co.,Ltd. Address before: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Patentee before: JOULWATT TECHNOLOGY (HANGZHOU) Co.,Ltd. |
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| CP01 | Change in the name or title of a patent holder |