TWM621790U - Power adapter - Google Patents

Abstract

The present creation discloses a power converter. According to an embodiment of the present invention, the power converter includes a control chip, an enable control circuit, a bootstrap circuit, and an output voltage sampling circuit, wherein: the control chip includes an enable control ENA pin, a VCC pin, a switch control SW pin, and a VB pin , and the output voltage feedback VFB pin, the first end of the enabling control circuit is connected to the input end of the power converter, the second end is connected to the ENA pin of the control chip, the third end is grounded, and the first end of the bootstrap circuit is connected to The VCC pin of the control chip, the second end is connected to the SW pin of the control chip, the third end is connected to the VB pin of the control chip, and the first end of the output voltage sampling circuit is connected to the output end of the power converter, and the second end is connected to To the VFB pin of the control chip, the third terminal is grounded. Through the power converter provided by this creation, the overall system cost can be reduced and the system reliability can be improved.

Description

power converter

This creation belongs to the field of integrated circuits, and particularly relates to a power converter.

With the increasing popularity of battery cars, people have higher and higher requirements for their power converters. At present, although the traditional power converter is relatively mature in technology, there is still room for improvement in the aspects of system cost, efficiency, safety and reliability that people are concerned about.

This creative embodiment provides a power converter, which can reduce system cost and improve system reliability.

On the one hand, an embodiment of the present invention provides a power converter, including: a control chip, an enable control circuit, a bootstrap circuit, and an output voltage sampling circuit, wherein: the control chip includes an enable control ENA pin, a VCC pin, a switch Control SW pin, VB pin, and output voltage feedback VFB pin, the first end of the enabling control circuit is connected to the input end of the power converter, the second end is connected to the ENA pin of the control chip, the third end The first end of the bootstrap circuit is connected to the VCC pin of the control chip, the second end is connected to the SW pin of the control chip, and the third end is connected to the VB pin of the control chip. The first end of the output voltage sampling circuit is connected to the output end of the power converter, the second end is connected to the VFB pin of the control chip, and the third end is grounded.

According to the power converter provided in the embodiment of the present invention, the control chip further includes a power input VIN pin, the power converter further includes a first voltage detection unit, and the first voltage detection unit is used for detecting the VIN When the voltage difference between the pin and the SW pin is greater than the first threshold, the current limiting protection function inside the control chip is triggered.

According to the power converter provided by the embodiment of the present invention, the first voltage detection The measuring unit includes a resistor and a transistor connected in series between the VIN pin and the SW pin, wherein the transistor is turned on under the control of the bootstrap circuit.

According to the power converter provided by this creative embodiment, the bootstrap circuit includes a diode and a capacitor, wherein the diode is connected between the VCC pin and the VB pin, and the capacitor is connected between the between the VB pin and the SW pin.

According to the power converter provided in the embodiment of the present invention, the enabling control circuit includes a switch, a first voltage dividing resistor and a second voltage dividing resistor, wherein one end of the switch is connected to the input end of the power converter, The other end of the switch is connected to one end of the first voltage dividing resistor, the other end of the first voltage dividing resistor is connected to the ENA pin and one end of the second voltage dividing resistor, and the second voltage dividing resistor is connected. The other end of the piezoresistor is grounded.

According to the power converter provided by the embodiment of the present invention, the enabling control circuit further includes a voltage regulator tube, and both ends of the voltage regulator tube are connected to both ends of the second voltage dividing resistor.

According to the power converter provided by the embodiment of the present invention, the control chip further includes a delay unit, and the delay unit is connected to the ENA pin for delaying a preset period of time when the voltage at the ENA pin is pulled to 0V The control wafer is then stopped.

According to the power converter provided in the embodiment of the present invention, the control chip further includes a second voltage detection unit connected to the VIN pin, and the second voltage detection unit pin is used for detecting the voltage at the VIN pin The input overvoltage protection function is triggered when it is higher than the second threshold, and the input undervoltage protection function is triggered when it is detected that the voltage at the VIN pin is lower than the third threshold.

According to the power converter provided by the embodiment of the present invention, the control chip further includes a third voltage detection unit connected to the VFB pin, for triggering an output when it is detected that the voltage at the VFB pin is higher than a fourth threshold An overvoltage protection function, and a short circuit protection function is triggered when it is detected that the voltage at the VFB pin is lower than the fifth threshold.

According to the power converter provided by this creative embodiment, the output voltage sampling circuit includes a third voltage dividing resistor and a fourth voltage dividing resistor, wherein one end of the third voltage dividing resistor is connected to the output of the power converter terminal, the other terminal of the third voltage dividing resistor is connected to To one end of the fourth voltage dividing resistor and the VFB pin, the other end of the fourth voltage dividing resistor is grounded.

According to the power converter provided in the embodiment of the present invention, the control chip further includes a temperature detection unit, configured to trigger an over-temperature protection function when it is detected that the temperature of the control chip is higher than a sixth threshold.

According to the power converter provided by the inventive embodiment, the power converter includes a step-down power converter.

The power converter provided in this creative embodiment can reduce system cost and improve system reliability.

100, 200, 300: Power Converter

110: Drive Transformer

120: Main control integrated circuit

130: Current Transformer

220: optocoupler+431

310: Control chip (OB21082)

320: enable control circuit

330: Bootstrap Circuit

340: Output voltage sampling circuit

C1: Input filter capacitor

C2: Control chip power supply filter capacitor

C3: Capacitor

C4: output filter capacitor

D1: Diode

D2: Chip power supply diode

L: Inductance

M1: Transistor

Q1: High-end MOS tube

Q2: low-end MOS tube

R1, R2, R4, R5, Rq: resistance

R3: Overcurrent adjustment resistor

SW: switch

VIN: Input voltage (power input pin/terminal)

Vout: output voltage/terminal

Z: Zener tube

In order to more clearly illustrate the technical solutions of this creative embodiment, the following will briefly introduce the accompanying drawings that need to be used in this creative embodiment. For those of ordinary skill in the art, without any creative effort, the Additional drawings can be obtained from these drawings.

FIG. 1 shows a schematic diagram of the circuit structure of a power converter 100 provided in the prior art;

FIG. 2 shows a schematic diagram of the circuit structure of another power converter 200 provided by the prior art;

FIG. 3 shows a schematic diagram of the structure of the power converter 300 provided in the embodiment of the present invention;

FIG. 4 shows a schematic circuit diagram of a voltage detection unit in a power converter provided by an embodiment of the present invention; and

FIG. 5 shows a schematic circuit diagram of the enable control circuit 320 in the power converter provided in the embodiment of the present invention.

The features and exemplary embodiments of various aspects of the present creation will be described in detail below. In order to make the purpose, technical solutions and advantages of the present creation more clear, the present creation will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the tools described herein The embodiments are only configured to explain the present composition, and are not configured to limit the present composition. It will be apparent to those skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating an example of the invention.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element defined by the phrase "comprises" does not preclude the presence of additional identical elements in a process, method, article, or device that includes the element.

It can be understood that the efficiency of the power converter can directly affect the volume of the entire power converter, which may ultimately affect the overall cost. For example, in terms of safety and reliability, for example, when the output is short-circuited, whether it will cause the output line to overheat and burn or damage the internal devices; whether it can trigger protection in time to avoid overheating of the power converter when the load is overcurrent; when the battery voltage is too low Or whether it can cut off the output to protect the battery or converter and so on when it is too high. In the traditional power converter, its cost, efficiency, reliability, and practicability need to be further improved. Therefore, the present invention provides a power converter that can solve the above technical problems.

In order to better understand the present creation, the following first introduces the conventional power converter in the prior art.

Specifically, referring to FIG. 1 , FIG. 1 shows a schematic diagram of a circuit structure of a power converter 100 provided in the prior art.

As shown in FIG. 1 , such a conventional power converter 100 includes an input filter capacitor C1, a transistor M1, a driving transformer 110, a main control integrated circuit (IC) 120, a current transformer 130, and a diode D1 , inductor L and control chip power supply filter capacitor C2.

Compared with the conventional power converter, the power converter provided by the present invention (which will be described in detail below) can omit the driving transformer 110 and the current transformer 130. It can be seen that the power converter provided by the present work can reduce the overall system cost.

In addition, referring to FIG. 2 , FIG. 2 shows a schematic diagram of a circuit structure of another power converter 200 provided in the prior art.

As shown in FIG. 2 , such a conventional power converter 200 includes an input filter capacitor C1, a transistor M1, a main control IC 210, an optocoupler +431220, a diode D1, an inductor L and a control chip power supply filter capacitor C2.

Compared with this traditional power converter, the power converter provided by this creation (will be described in detail below) can save the optocoupler +431 220. It can be seen that the power converter provided by this creation can reduce the overall system cost.

In order to solve the problem of the prior art, the present invention provides a power converter. The following first introduces the power converter provided by this creative embodiment.

FIG. 3 shows a schematic structural diagram of the power converter 300 provided in the embodiment of the present invention. As shown in FIG. 3 , the power converter 300 may include a control chip 310 (eg, OB21082), an enabling control circuit 320, a bootstrap circuit 330, an output voltage sampling circuit 340, an input filter capacitor C1, and a control chip power supply filter capacitor C2, overcurrent adjustment resistor R3, high-end MOS tube Q1, low-end MOS tube Q2, inductor L, chip power supply diode D2, output filter capacitor C4, etc. Among them, OB21082 is a dedicated control chip for battery car power converters.

As an example, the control chip 310 may include an enable control ENA pin, a ground GND pin, a bootstrap capacitor charging VCC pin, an output voltage feedback VFB pin, a power input VIN pin, a bootstrap voltage VB pin, a high-side switch driver GH pin, and a switch Control SW pins, etc. The first end of the enabling control circuit 320 may be connected to the input end VIN of the power converter, the second end may be connected to the ENA pin of the control chip 310, and the third end may be grounded; the first end of the bootstrap circuit 330 may be Connected to the VCC pin of the control chip 310, the second end can be connected to the SW pin of the control chip 310, the third end can be connected to the VB pin of the control chip 310; and the first end of the output voltage sampling circuit 340 can be connected to the power conversion The output terminal Vout of the device, the second terminal can be connected to The VFB pin and the third terminal connected to the control chip 310 can be grounded.

Through the above-mentioned power converter provided in this creation, the drive transformer 110 and the current transformer 130 shown in FIG. 1 and the optocoupler +431 220 shown in FIG. 2 can be omitted, so the overall system cost can be reduced, and at the same time Can improve system reliability.

In some embodiments, the enable control circuit 320 may include a switch SW, two voltage dividing resistors (eg, a resistor R1 and a resistor R2 ), wherein the two voltage dividing resistors may be used to divide the input voltage VIN and convert The divided input voltage is input to the ENA pin of the control chip 310, one end of the switch SW can be connected to the input end VIN of the power converter, the other end of the switch SW can be connected to one end of the resistor R1, and the other end of the resistor R1 can be connected to To the ENA pin and one end of the resistor R2, the other end of the resistor R2 can be grounded.

In some other embodiments, the enabling control circuit 320 may include, in addition to the various elements in the foregoing embodiments, a voltage regulator Z, and both ends of the voltage regulator Z may be connected to both ends of the resistor R2, for example The negative pole of the Zener tube Z can be connected to the ENA pin of the control chip 310, the positive pole of the Zener tube Z can be grounded, and the Zener tube Z can be used to protect the ENA pin of the control chip 310 (described in detail below).

In some embodiments, the bootstrap circuit 330 may include a diode D1 and a capacitor C3, wherein the diode D1 may be connected between the VCC pin and the VB pin of the control chip 310, for example, the anode of the diode D1 may be connected To the VCC pin, the cathode of the diode D1 can be connected to the VB pin, the capacitor C3 can be connected between the VB pin and the SW pin of the control chip 310, and the bootstrap circuit 330 can be used to control the conduction of the high-side MOS transistor Q1.

In some embodiments, the output voltage sampling circuit 340 may include two voltage dividing resistors (eg, resistor R4 and resistor R5 ), wherein the two voltage dividing resistors may be used to divide the output voltage VOUT and divide the divided voltage The output voltage of the resistor R4 is input to the VFB pin of the control chip 310, one end of the resistor R4 can be connected to the output end of the power converter, the other end of the resistor R4 can be connected to one end of the resistor R5 and the VFB pin, and the other end of the resistor R5 can be grounded.

The control of the power converter provided by this creation is based on the COT architecture, which can keep the on-time unchanged when the load changes, and can stabilize the output signal by changing the frequency. When the power converter system enters the Continuous Conduction Mode (CCM) mode, the operating frequency does not vary with the input voltage and load.

The power converter provided by this creation may include a high-side MOS transistor Q1 and a low-side MOS transistor Q2. The drain of the high-end MOS transistor Q1 can be connected to the positive terminal of the input voltage, the gate of the high-end MOS transistor Q1 can be connected to the GH pin of the control chip 310, and the source of the high-end MOS transistor Q1 can be connected to the low-side MOS transistor Q2 The drain electrode of the low-side MOS transistor Q2 can be connected to the GH pin of the control chip 310, and the source electrode of the low-side MOS transistor Q2 can be grounded.

As an example, a bootstrap circuit 330 can be arranged around the control chip 310 to drive the high-side MOS transistor Q1, and the control chip 310 can be used to drive the low-side MOS transistor Q2.

The power converter provided by this creation uses the low-end MOS transistor Q2 to replace the freewheeling diode, and the synchronous control can effectively improve the system efficiency. In some embodiments, the control chip 310 provided by the present invention may integrate one or more of the following functions: input under-voltage/over-voltage protection function, output over-voltage protection function, cycle-by-cycle current limiting protection function, and short-circuit protection function , Over-temperature protection function, at the same time, it can have built-in enabling control, and the system can be controlled to start or stop working through an external switch. The implementation of each function is described in detail below.

Referring to FIG. 4 , FIG. 4 shows a schematic circuit diagram of a voltage detection unit in a power converter provided by the present invention. The voltage detection unit may be located outside the control chip 310 and connected to the VIN pin and the SW of the control chip 310 3 and 4, the voltage detection unit may include an overcurrent adjustment resistor R3 and a high-side MOS transistor Q1, wherein one end of the overcurrent adjustment resistor R3 may be connected to the VIN pin of the control chip 310 , the other end of the overcurrent adjustment resistor R3 can be connected to the drain of the high-end MOS transistor Q1, the gate of the high-end MOS transistor Q1 can be connected to the GH pin of the control chip 310, and the source of the high-end MOS transistor Q1 can be connected to the control chip 310 SW pin.

Specifically, as shown in FIG. 4 , the input voltage VIN is input to the VIN pin of the control chip 310, and is connected in series with the overcurrent adjustment resistor R3 to the drain of the high-side MOS transistor Q1, and then connected to the resistor Rq (the equivalent of the high-side MOS transistor Q1) internal resistance) is connected in series to the SW of the control chip 310 foot. As an example, the voltage detection unit can obtain the current flowing through the inductor by detecting the voltage difference between the VIN pin and the SW pin when the high-side MOS transistor Q1 is turned on. When the current of the inductor is greater than the preset threshold value inside the chip), the current limiting protection function of the control chip is triggered to limit the increase of power, so as to improve the reliability of the system.

In some embodiments, the control chip 310 may further include a voltage detection unit connected to the VIN pin of the control chip 310, and the voltage detection unit may be used to trigger the input when it is detected that the voltage at the VIN pin is higher than the first preset threshold Overvoltage protection function, and triggering the input undervoltage protection function when the voltage at the VIN pin is detected to be lower than the second preset threshold, so as to ensure the safety and reliability of the system, wherein the first preset threshold is greater than the second preset threshold .

In some embodiments, the control die 310 may further include a voltage detection unit connected to the VFB pin of the control die 310, the voltage detection unit may be used in abnormal conditions, such as detecting a voltage at the VFB pin that characterizes the output voltage The output overvoltage protection function is triggered when the third preset threshold is exceeded, thereby ensuring the reliability of the power converter system; and when the load current of the power converter system is greater than the internal current limit value of the chip, the output voltage of the system will drop, thereby The voltage at the VFB pin, which represents the output voltage, decreases accordingly, so the short-circuit protection function can be triggered when it is detected that the voltage at the VFB pin is lower than the fourth preset threshold, where the third preset threshold is greater than the fourth preset threshold.

In some embodiments, the control wafer 310 may include a temperature detection unit, which is used to trigger an over-temperature protection function when an abnormal situation occurs in the system, for example, when it is detected that the temperature of the control wafer is higher than an internally set threshold. The system can stop working to improve the reliability of the system.

In some embodiments, the control die 310 may have a built-in enable control, and the control die 310 may be started or stopped by applying, for example, a high level or a low level to the ENA pin of the control die 310 . Referring to FIG. 5 , FIG. 5 shows a schematic circuit diagram of the enable control circuit 320 in the power converter provided by the present invention. Among them, the switch SW is an external control switch, which can be regarded as a main power supply switch such as a vehicle lamp, a dashboard, and a USB.

As an example, when the switch SW is turned on, the control wafer 310 may be enabled start working. Specifically, when the switch SW is turned on, the power converter can output a given voltage to supply power to various devices. After turning on VIN, the ENA pin of the control chip 310 can obtain a certain voltage after the input voltage VIN is divided by the resistors R1 and R2. When the input voltage VIN is sufficiently high (for example, higher than a certain threshold), the input voltage is characterized The voltage at the ENA pin of VIN can be higher than the internal preset threshold, and the control chip 310 starts to work at this time.

In an optional embodiment, when the input voltage VIN continues to increase, the voltage at the ENA pin will not increase when it reaches the regulated value of the Zener tube Z. It can be seen that the Zener tube Z can be used to protect the control chip 310 It should be understood that in some scenarios where the range of the input voltage VIN of some systems is narrow, the voltage regulator Z may not be needed.

When the switch SW is turned off, the control chip 310 can be stopped from working. Specifically, when the switch SW is turned off, the ENA pin of the control chip 310 is pulled to a low level (for example, 0V). The control chip 310 may further include a delay unit, and the delay unit may be connected to the ENA pin of the control chip 310, It can be used to stop the control chip 310 from working after a preset time period (for example, 20 seconds) of the chip internal control delay when the voltage at the ENA pin is pulled to 0V. This delay function can be applied to the car owner who needs lighting for a period of time after parking. In the scenario where the power supply of the whole vehicle is turned off, and this delay function can be realized by means of chip integration, there is no need to build complex circuits, making the system more practical.

The power converter provided by this creation may be a step-down power converter, which should not be construed as limiting, it may also be other suitable type of power converter without departing from the spirit and scope of this creation .

In summary, the non-isolated step-down battery car power converter provided by this creation can be used in scenarios where the converter has functions such as chip enable, delay shutdown, over-current protection, over-temperature protection, short-circuit protection, etc. , the control circuit has the advantages of better system cost, high efficiency and high reliability.

To be clear, the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above-described embodiments, several specific steps are described and shown as examples. However, this The method process of the creation is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after comprehending the spirit of the invention.

The functional blocks shown in the structural block diagrams described above can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, it can be, for example, electronic circuits, application specific integrated circuits (ASICs), suitable firmware, plug-ins, function cards, and the like. When implemented in software, elements of the present authoring are programs or pieces of code that are used to perform the desired task. The program, or segments of program code, can be stored on a machine-readable medium or transmitted over a transmission medium or communication link by a data signal carried in a carrier wave. A "machine-readable medium" may include any medium that can store or transmit information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (Erasable Read Only Memory, EROM), floppy disk, (Compact Disc Read-Only Memory, CD-ROM) , optical discs, hard disks, optical media, radio frequency (Radio Frequency, RF) links, and so on. The code snippets may be downloaded via a computer network such as the Internet, an intranet, or the like.

It should also be noted that, the exemplary embodiments mentioned in this creation describe some methods or systems based on a series of steps or devices. However, the present creation is not limited to the order of the above steps, that is, the steps may be performed in the order mentioned in the embodiment, or may be different from the order in the embodiment, or several steps may be performed simultaneously.

The above are only specific implementations of the present creation, and those skilled in the art can clearly understand that, for the convenience and simplicity of the description, the specific working process of the above-described systems, modules and units can be implemented with reference to the aforementioned methods. The corresponding process in the example will not be repeated here. It should be understood that the protection scope of this creation is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by this creation, and these modifications or replacements should be covered in within the scope of protection of this creation.

300: Power Converter

310: Control chip (OB21082)

320: enable control circuit

330: Bootstrap Circuit

340: Output voltage sampling circuit

C1: Input filter capacitor

C2: Control chip power supply filter capacitor

C3: Capacitor

C4: output filter capacitor

D1: Diode

D2: Chip power supply diode

L: Inductance

Q1: High-end MOS tube

Q2: low-end MOS tube

R1, R2, R4, R5: Resistors

R3: Overcurrent adjustment resistor

SW: switch

VIN: Input voltage (power input pin/terminal)

Vout: output voltage/terminal

Z: Zener tube

Claims (12)

A power converter, characterized in that it includes a control chip, an enabling control circuit, a bootstrap circuit, and an output voltage sampling circuit, wherein: The control chip includes an ENA pin for enabling control, a bootstrap capacitor charging VCC pin, a switch control SW pin, a bootstrap voltage VB pin, a high-side switch driving GH pin and an output voltage feedback VFB pin, The first end of the enabling control circuit is connected to the input end of the power converter, the second end is connected to the ENA pin of the control chip, and the third end is grounded, The first end of the bootstrap circuit is connected to the VCC pin of the control chip, the second end is connected to the SW pin of the control chip, the third end is connected to the VB pin of the control chip, and The first end of the output voltage sampling circuit is connected to the output end of the power converter, the second end is connected to the VFB pin of the control chip, and the third end is grounded. The power converter according to claim 1, wherein the control chip further comprises a power input VIN pin, the power converter further comprises a first voltage detection unit, and the first voltage detection unit is used for detecting When the voltage difference between the VIN pin and the SW pin is greater than the first threshold, the current limiting protection function inside the control chip is triggered. The power converter according to claim 2, wherein the first voltage detection unit comprises a resistor and a transistor connected in series between the VIN pin and the SW pin, wherein the transistor is It is turned on under the control of the bootstrap circuit. The power converter according to claim 1, wherein the bootstrap circuit comprises a diode and a capacitor, wherein the diode is connected between the VCC pin and the VB pin, the A capacitor is connected between the VB pin and the SW pin. The power converter according to claim 1, wherein the enabling control circuit comprises a switch, a first voltage dividing resistor and a second voltage dividing resistor, wherein one end of the switch is connected to the power converter the input end of the switch, the other end of the switch is connected to one end of the first voltage dividing resistor, and the other end of the first voltage dividing resistor is connected to the ENA pin and one end of the second voltage dividing resistor, so The other end of the second voltage dividing resistor is grounded. The power converter according to claim 5, wherein the enabling control circuit further comprises a voltage regulator tube, and both ends of the voltage regulator tube are connected to both ends of the second voltage dividing resistor. The power converter according to claim 1, wherein the control chip further comprises a delay unit, and the delay unit is connected to the ENA pin for when the voltage at the ENA pin is pulled to 0V The control wafer is stopped from working after a preset time delay. The power converter according to claim 2, wherein the control chip further comprises a second voltage detection unit connected to the VIN pin, and the second voltage detection unit pin is used for detecting the VIN The input overvoltage protection function is triggered when the voltage at the pin is higher than the second threshold, and the input undervoltage protection function is triggered when it is detected that the voltage at the VIN pin is lower than the third threshold. The power converter according to claim 1, wherein the control chip further comprises a third voltage detection unit connected to the VFB pin, for detecting that the voltage at the VFB pin is higher than a fourth voltage The output overvoltage protection function is triggered when the threshold value is reached, and the short circuit protection function is triggered when it is detected that the voltage at the VFB pin is lower than the fifth threshold value. The power converter according to claim 1, wherein the output voltage sampling circuit comprises a third voltage dividing resistor and a fourth voltage dividing resistor, wherein one end of the third voltage dividing resistor is connected to the power supply For the output end of the converter, the other end of the third voltage dividing resistor is connected to one end of the fourth voltage dividing resistor and the VFB pin, and the other end of the fourth voltage dividing resistor is grounded. The power converter according to claim 1, wherein the control chip further comprises a temperature detection unit for triggering an over-temperature protection function when it is detected that the temperature of the control chip is higher than a sixth threshold. The power converter of claim 1, wherein the power converter comprises a step-down power converter.

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