Auxiliary power supply system and electronic equipment

Abstract

The present application provides an auxiliary power supply system and electronic device, including a power chip, a first power supply circuit, a second power supply circuit, a drive circuit and a feedback circuit. The first power supply circuit is arranged between an external power supply and a power chip, and supplies power for the startup operation and output of a first drive signal of the power chip; the drive circuit is arranged between the power chip and the second power supply circuit, and drives the external power supply and the second power supply circuit to switch between on and off according to the first drive signal, so that the second power supply circuit converts the input voltage of the external power supply into an output voltage of a first threshold value; the feedback circuit is arranged at the output end of the second power supply circuit, and outputs a second drive signal to the first power supply circuit when the output voltage is abnormal, so that the first power supply circuit drives the power chip to stop outputting the first drive signal, and then stops the drive circuit from working, so as to achieve the purpose of protecting the auxiliary source and reducing the loss of the auxiliary source system.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to an auxiliary power supply system and electronic equipment. Background Art

[0002] The switching power supply uses modern power electronics technology to convert a voltage level into the voltage or current required by the user end using different forms of architecture. The input of the switching power supply is mostly AC power (such as mains) or DC power, and the output is mostly devices that require DC power, such as personal computers, mobile phones, or electronic devices such as vehicle-mounted power supply structures. The switching power supply converts the voltage and current between the two. The working principle of the switching power supply is mainly to control the output voltage by adjusting the duty cycle of the switching tube. At present, switching power supplies have been widely used. With the rapid development of electronic devices or equipment, various topologies have been realized in many electronic devices, making the existing auxiliary power supply system more and more complex. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the first purpose of the present application is to propose an auxiliary source power supply system and electronic equipment, which can promptly cut off power for protection when the auxiliary source output voltage is abnormal, thereby achieving the effect of reducing the loss of the auxiliary source system and protecting the auxiliary source.

[0005] The second objective of the present application is to propose an auxiliary power supply system and an electronic device, which can simplify the existing auxiliary power supply system while meeting the existing auxiliary power supply needs, so as to reduce the use cost of the auxiliary power supply system.

[0006] To achieve the above-mentioned purpose, the first embodiment of the present application proposes an auxiliary power supply system, including a power supply chip, a first power supply circuit, a second power supply circuit, a drive circuit and a feedback circuit; wherein,

[0007] The first power supply circuit is arranged between an external power supply and the power supply chip, the second power supply circuit is arranged between the external power supply, the driving circuit is arranged between the power supply chip and the second power supply circuit, and the feedback circuit is arranged between the second power supply circuit and the first power supply circuit;

[0008] The first power supply circuit is configured to supply power for the startup operation of the power supply chip when it is turned on, and drive the power supply chip to output a first drive signal. The drive circuit drives the loop between the external power supply and the second power supply circuit to switch between on and off according to the first drive signal, so that the second power supply circuit converts the input voltage of the external power supply into an output voltage of a first threshold value; the feedback circuit is configured to output a second drive signal to the first power supply circuit when the output voltage is lower than the first threshold or higher than the first threshold, and the first power supply circuit drives the power supply chip to stop outputting the first drive signal according to the second drive signal.

[0009] Optionally, the first power supply circuit includes a soft-start resistor and a first diode, and the input voltage of the external power supply sequentially supplies power to the VCC terminal of the power supply chip through the soft-start resistor and the first diode; wherein the external power supply is connected to the first end of the soft-start resistor and the input end of the second power supply circuit, the second end of the soft-start resistor is connected to the first end of the first diode, and the second end of the first diode is connected to the VCC terminal of the power supply chip.

[0010] Optionally, the first power supply circuit also includes a comparator, a first resistor, a first capacitor and a first switch tube; wherein, the non-inverting end of the comparator is connected to the reference voltage, the inverting end of the comparator is connected to the second end of the soft-start resistor, the first end of the first diode, and the first end of the first resistor, and the output end of the comparator is connected to the ZCS end of the power chip; the first end of the first switch tube is connected to the second end of the first resistor and the first end of the first capacitor, the second end of the first switch tube is connected to the second end of the first capacitor and grounded, and the third end of the first switch tube is connected to the output end of the feedback circuit and the COMP end of the power chip.

[0011] Optionally, the first switching tube is an NPN transistor; when the second drive signal is at a high level, the first switching tube is turned on, and the output end of the comparator will output a low-level control signal to the ZCS end of the power chip, causing the power chip to stop outputting the first drive signal.

[0012] Optionally, the second power supply circuit includes a transformer, an input loop connected to the primary winding of the transformer, and an output loop connected to the first secondary winding of the voltage generator; wherein the input end of the input loop is connected to the external power supply, the output end of the input loop is connected to the drive circuit, and the output end of the output loop is connected to the input end of the feedback circuit.

[0013] Optionally, the input loop includes a second capacitor, a third capacitor, a second resistor and a second diode, and the output loop includes a fourth capacitor, a fifth capacitor, a sixth capacitor, a third diode and a third resistor; wherein,

[0014] The first end of the second capacitor is connected to the first end of the second resistor, the first end of the third capacitor, the first end of the primary winding, and the external power supply, the second end of the second capacitor is grounded, the second end of the second resistor is connected to the second end of the third capacitor and the second end of the second diode; the second end of the primary winding is connected to the first end of the second diode and the driving circuit;

[0015] The first end of the first secondary winding is connected to the first end of the third diode and the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the first end of the third resistor, the second end of the third resistor is connected to the second end of the third diode, the first end of the fifth capacitor, the first end of the sixth capacitor, the input end of the feedback circuit, and the first output end of the output loop, and the second end of the first secondary winding is connected to the second end of the fifth capacitor, the second end of the sixth capacitor, and the second output end of the output loop.

[0016] Optionally, the second power supply circuit also includes a power supply loop connected to the second secondary winding of the transformer, and the power supply loop includes a fifth diode and an eighth capacitor; wherein the first end of the fifth diode is connected to the first end of the second secondary winding, the second end of the fifth diode is connected to the first end of the eighth capacitor and the first output end of the power supply loop, and the first output end of the power supply loop is also connected to the second end of the first diode and the VCC end of the power supply chip; the second end of the second secondary winding is connected to the second end of the eighth capacitor and the second output end of the power supply loop and is grounded.

[0017] Optionally, the driving circuit includes a second switch tube, a third switch tube, a fourth switch tube, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh capacitor; wherein, the first end of the fourth resistor is connected to the Gate end of the power chip, the second end of the fourth resistor is connected to the third end of the second opening tube and the third end of the third switch tube, the first end of the second switch tube is connected to the second end of the third switch tube and the first end of the sixth resistor, the second end of the second switch tube is connected to the second end of the first diode, the first end of the seventh capacitor, and the VCC end of the power chip, the second end of the third switch tube is connected to the second end of the seventh capacitor and grounded, the second end of the sixth resistor is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the first end of the seventh resistor and the third end of the fourth switch tube, the first end of the fourth switch tube is connected to the second power supply circuit, and the second end of the fourth switch tube is connected to the second end of the seventh resistor and grounded.

[0018] Optionally, the second switch tube is an NPN transistor, the third switch tube is a PNP transistor, and the fourth switch tube is an NPN MOS tube; wherein,

[0019] When the first driving signal is at a high level, the third switch tube is turned off, and the second switch tube and the fourth switch tube are turned on in sequence, and drive the second power supply circuit to be fully turned on;

[0020] When the second driving signal is at a low level, the second switch tube and the fourth switch tube are turned off, the third switch tube is turned on, and drives the second power supply circuit to be partially turned on.

[0021] To achieve the above-mentioned purpose, a second aspect of the present application provides an electronic device, which includes the auxiliary power supply system described in any one of the above items.

[0022] The auxiliary power supply system and electronic device provided by the present application have at least the following beneficial effects:

[0023] The present application provides an auxiliary power supply system and electronic equipment, including a power chip, a first power supply circuit, a second power supply circuit, a drive circuit and a feedback circuit. The first power supply circuit is arranged between an external power supply and a power chip, and supplies power for the startup operation and output of a first drive signal of the power chip; the drive circuit is arranged between the power chip and the second power supply circuit, so that the drive circuit drives the external power supply and the second power supply circuit to switch between on and off according to the first drive signal, so that the second power supply circuit can convert the input voltage of the external power supply into an output voltage output of a first threshold value; the feedback circuit is arranged at the output end of the second power supply circuit, and outputs a second drive signal to the first power supply circuit when the output voltage is abnormal, so that the first power supply circuit drives the power chip to stop outputting the first drive signal, and then stops the drive circuit from working, so as to achieve the purpose of protecting the auxiliary source and reducing the loss of the auxiliary source system.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 The figure is a schematic diagram of the structure of an auxiliary power supply system according to an embodiment of the present application.

[0027] Figure 2 The topology diagram of a auxiliary power supply system according to an embodiment of the present application is shown.

[0028] 10 first power supply circuit; 20 second power supply circuit; 30 drive circuit; 40 feedback circuit. DETAILED DESCRIPTION

[0029] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0030] According to one aspect of the present application, an auxiliary power supply system is provided, such as Figure 1 and Figure 2As shown, it includes an external power supply, a power chip, a first power supply circuit 10, a second power supply circuit 20, a drive circuit 30 and a feedback circuit 40. Among them, the first power supply circuit 10 is arranged between the external power supply and the power chip, the second power supply circuit 20 is connected to the external power supply, the drive circuit 30 is arranged between the power chip and the second power supply circuit 20, and the feedback circuit 40 is arranged between the second power supply circuit 20 and the first power supply circuit 10.

[0031] It can be understood that by arranging the first power supply circuit 10 between the external power supply and the power chip, the external power supply can supply power for the startup and operation of the power chip through the first power supply circuit 10. At the same time, by arranging the second power supply circuit 20 to be connected to the external power supply, the second power supply circuit 20 can convert the input voltage of the external power supply into an output voltage of the first threshold value for output.

[0032] Since the driving circuit 30 is arranged between the power chip and the second power supply circuit 20, the first driving signal output by the power chip during operation can be input to the driving circuit 30. The driving circuit 30 drives the loop between the external power supply and the second power supply circuit 20 to switch between the on state and the off state according to the input first driving signal, so that the second power supply circuit 20 can convert the input voltage of the external power supply into an output voltage of the first threshold value.

[0033] Since the feedback circuit 40 is arranged between the second power supply circuit 20 and the first power supply circuit 10, the feedback circuit 40 can detect and feedback the output voltage output by the second power supply circuit 20 in real time, and output the second drive signal to the first power supply circuit 10 when there is an abnormality in the output voltage, such as no output voltage, or the output voltage is significantly lower than the first threshold, or the output voltage is significantly higher than the first threshold. The first power supply circuit 10 drives the power supply chip to stop outputting the first drive signal according to the input second drive signal, so that the second power supply circuit 20 remains in the off state, and the second power supply circuit 20 stops outputting the output voltage of the first threshold to the outside.

[0034] The auxiliary power supply system provided by the present application can reduce the design and use costs of the auxiliary power supply system by simplifying the peripheral circuit of the power supply chip. At the same time, when the output state of the output voltage output by the second power supply circuit 20 is abnormal, the second drive signal fed back by the feedback circuit 30 can timely drive the power supply chip to shut down the loop between the second power supply circuit 20 and the external power supply, thereby reducing the loss of the power supply chip, each switch tube, diode and other devices in the auxiliary power supply system, and achieving the purpose of protecting the auxiliary source.

[0035] In some embodiments, the first power supply circuit 10 includes a soft-start resistor and a first diode D1, and the input voltage of the external power supply is connected to the VCC terminal of the power chip through the soft-start resistor and the first diode D1 in sequence to provide power for the startup and operation of the power chip. The external power supply is connected to the first end of the soft-start resistor, the second end of the soft-start resistor is connected to the first end of the first diode D1, and the second end of the first diode D1 is connected to the VCC terminal of the power chip.

[0036] The soft-start resistor can play the role of voltage division and current limiting protection in the first power supply circuit 10. At the same time, in order to ensure that the power chip can be charged slowly, the resistance of the soft-start resistor must be high enough. The soft-start resistor can include four resistors in series, namely R01, R02, R03 and R04, to ensure that the resistance is large enough and has sufficient voltage division and current limiting protection effects.

[0037] Furthermore, the first power supply circuit 10 further includes a comparator U1, a first resistor R1, a first capacitor C1 and a first switch tube Q1. Among them, the in-phase terminal of the comparator U1 is connected to the reference voltage Vref, the inverting terminal of the comparator U1 is connected to the second end of the soft-start resistor, the first end of the first diode D1, and the first end of the first resistor R1, and the output end of the comparator U1 is connected to the ZCS end of the power chip; the first end of the first switch tube Q1 is connected to the second end of the first resistor R1 and the first end of the first capacitor C1, the second end of the first switch tube Q1 is connected to the second end of the first capacitor C1 and grounded, and the third end of the first switch tube Q1 is connected to the output end of the feedback circuit 40 and the COMP end of the power chip.

[0038] Since the inverting terminal of the comparator U1 is connected to the external power supply through the soft-start resistor, and the non-inverting terminal of the comparator U1 is connected to the reference voltage Vref, when the first switch tube Q1 is in the off state, the voltage input to the inverting terminal of the comparator U1 is equivalent to the output voltage of the external power supply, and is greater than the reference voltage Vref input to the non-inverting terminal of the comparator U1. Therefore, the output terminal of the comparator U1 will output a low-level control signal to the ZCS terminal of the power chip to drive the power chip to continuously output the first drive signal to the drive circuit 30.

[0039] At the same time, since the inverting terminal of the comparator U1 is also grounded through the first resistor R1 and the first switch tube Q1, when the first switch tube Q1 is in the on state, it is equivalent to grounding the inverting terminal of the comparator U1, and is less than the reference voltage Vref of the inverting terminal of the input comparator U1. Therefore, the output terminal of the comparator U1 will output a high-level control signal to the ZCS terminal of the power chip to drive the power chip to stop outputting the first drive signal to the drive circuit 30.

[0040] Since the third terminal of the first switch tube Q1 is connected to the output terminal of the feedback circuit 40 and the COMP terminal of the power chip, the first switch tube Q1 can switch from the off state to the on state under the drive of the second drive signal output by the feedback circuit 40 .

[0041] As an example, when the first switch tube Q1 is an NPN transistor, and the feedback circuit 40 detects that the output voltage output by the second power supply circuit 20 is abnormal, such as no output voltage, or the output voltage is significantly lower than the first threshold, or the output voltage is significantly higher than the first threshold, the feedback circuit 40 will output a high-level second drive signal to the third end of the first switch tube Q1 and the COMP end of the power chip, thereby driving the power chip to stop outputting the first drive signal to the drive circuit 30, thereby achieving the purpose of protecting the auxiliary source.

[0042] In some embodiments, the driving circuit 30 includes a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh capacitor C7. Among them, the first end of the fourth resistor R4 is connected to the Gate end of the power chip, the second end of the fourth resistor R4 is connected to the third end of the second opening tube Q2 and the third end of the third switch tube Q3, the second end of the second switch tube Q2 is connected to the second end of the third switch tube Q3 and the first end of the sixth resistor R6, the first end of the second switch tube Q2 is connected to the second end of the first diode D1, the first end of the seventh capacitor C7, and the VCC end of the power chip, the first end of the third switch tube Q3 is connected to the second end of the seventh capacitor C7 and grounded, the second end of the sixth resistor R6 is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected to the first end of the seventh resistor R7 and the third end of the fourth switch tube Q4, the first end of the fourth switch tube Q4 is connected to the second power supply circuit 20, and the second end of the fourth switch tube Q4 is connected to the second end of the seventh resistor R7 and grounded.

[0043] Since the Gate terminal of the power chip is connected to the third terminals of the second switch tube Q2 and the third switch tube Q3 respectively through the fourth resistor R4, the first drive signal output by the power chip through the Gate terminal can switch the on-off state of the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4, and then switch the loop between the external power supply and the second power supply circuit 20 between the on state and the off state, so that the second power supply circuit 20 can convert the input voltage of the external power supply into an output voltage of the first threshold value for output.

[0044] As an example, the second switch tube Q2 is an NPN transistor, the third switch tube Q3 is a PNP transistor, and the fourth switch tube Q4 is an NPN MOS tube. When the first drive signal is at a high level, the third switch tube Q3 is turned off, the second switch tube Q2 is turned on, and the fourth switch tube Q4 is turned on in sequence, and the loop between the external power supply and the second power supply circuit 20 is driven to be turned on. On the contrary, when the second drive signal is at a low level, the second switch tube Q2 and the fourth switch tube Q4 are turned off, and the third switch tube Q3 is turned on, thereby driving the loop between the external power supply and the second power supply circuit 20 to be turned off. Thus, the drive circuit 30 controls the external power supply and the second power supply circuit 20 to periodically switch between the on state and the off state, thereby enabling the second power supply circuit 20 to convert the input voltage of the external power supply into an output voltage of the first threshold value for output.

[0045] In some embodiments, the second power supply circuit 20 includes a transformer T, an input loop connected to the primary winding of the transformer T, and an output loop connected to the first secondary winding of the transformer T. The input end of the input loop is connected to an external power source, the output end of the input loop is connected to the drive circuit 30, and the output end of the output loop is connected to the input end of the feedback circuit 40.

[0046] Since the input end of the input loop is connected to the external power supply, and the output end of the input loop is connected to the drive circuit 30, the loop between the external power supply and the input loop can be periodically switched between the on state and the off state under the drive of the drive circuit 30, so that the input loop can convert the output voltage of the external power supply into an output voltage of the first threshold through the transformer T, and output it stably to the outside through the output loop.

[0047] The input loop may specifically include a second capacitor C2, a third capacitor C3, a second resistor R2, and a second diode D2. The first end of the second capacitor C2 is connected to the first end of the second resistor R2, the first end of the third capacitor C3, the first end of the primary winding, and the external power supply, the second end of the second capacitor C2 is grounded, the second end of the second resistor R2 is connected to the second end of the third capacitor C3, and the second end of the second diode D2, and the second end of the primary winding is connected to the first end of the second diode D2 and the drive circuit 30 (the first end of the fourth switch tube Q4).

[0048] The output loop specifically includes a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a third diode D3 and a third resistor R3. The first end of the first secondary winding is connected to the first end of the third diode D3 and the first end of the fourth capacitor C4, the second end of the fourth capacitor C4 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is connected to the second end of the third diode D3, the first end of the fifth capacitor C5, the first end of the sixth capacitor C6, the input end of the feedback circuit 40, and the first output end of the output loop, the second end of the first secondary winding is connected to the second end of the fifth capacitor C5, the second end of the sixth capacitor C6, and the second output end of the output loop, and the second output end of the output loop is analog grounded.

[0049] When the drive circuit 30 drives the input circuit to be in the on state under the drive of the first drive signal, the output circuit outputs the output voltage of the first threshold value through the Vout port, and the fifth capacitor C5 and the sixth capacitor C6 of the output circuit are charged by energy storage. When the drive circuit 30 drives the input circuit to be in the off state under the drive of the first drive signal, the fifth capacitor C5 and the sixth capacitor C6 of the output circuit are discharged outwardly, so that the output circuit can continuously output the output voltage of the first threshold value through the Vout port. In other words, by adjusting the duty cycle of the first drive signal, the working time of the input circuit can be adjusted so that the power stored in the fifth capacitor C5 and the sixth capacitor C6 meets the normal power supply requirement of the output circuit when the input circuit is not working.

[0050] In addition, since the output end of the output loop is connected to the input end of the feedback circuit 40, the feedback loop can judge the output state of the output loop according to the output voltage output by the output loop, and output the second drive signal to the first power supply circuit 10 when the output voltage of the output loop is significantly lower than or higher than the first threshold, or there is no output voltage, so as to turn on the first switch tube Q1, thereby driving the power chip to stop outputting the first drive signal (or continuously outputting a low-level drive signal). As a result, the input loop will be completely in the off state, and the output loop will no longer output voltage to the outside.

[0051] The second power supply circuit 20 also includes a power supply loop connected to another secondary winding (which may be a second secondary winding) of the transformer T, and the power supply loop includes a fifth diode D5 and an eighth capacitor C8. Among them, the first end of the fifth diode D5 is connected to the first end of the second secondary winding, the second end of the fifth diode D5 is connected to the first end of the eighth capacitor C8, and the first output end of the power supply loop, and the first output end of the power supply loop is also connected to the second end of the first diode D1, the first end of the second switch tube Q2, and the VCC end of the power chip; the second end of the second secondary winding is connected to the second end of the eighth capacitor C8 and the second output end of the power supply loop and is grounded.

[0052] Since the power supply circuit is composed of the second secondary winding of the transformer T, the fifth diode D5 and the eighth capacitor C8 connected together, the working principle is basically the same as that of the output circuit, so that the output voltage of the external power supply is converted into an output voltage of the second threshold through the transformer T, and is stably outputted to the outside by the power supply circuit. At the same time, the circuit stored in the eighth capacitor C8 can also meet the normal power supply requirements of the power chip when the input circuit is not working.

[0053] Since the input circuit is connected to the external power supply, the lower circuit load of the input circuit will short-circuit the first power supply circuit 10 between the external power supply and the power supply end of the power supply chip, so that the external power supply no longer supplies power to the power supply chip through the first power supply circuit. Therefore, by connecting the first output end of the power supply circuit to the second end of the first diode D1 and the VCC end of the power supply chip, the output voltage of the second threshold output by the power supply circuit can be directly used to supply power for the operation of the power supply chip. In other words, the power supply end of the power supply chip is respectively connected to two sets of independent power supply circuits. Among them, the first power supply circuit composed of the external power supply and the first power supply circuit can supply power for the initial startup operation of the power supply chip, and the second power supply circuit composed of the second secondary winding of the transformer can replace the first power supply circuit to supply power for the continuous operation of the power supply chip, thereby reducing the power consumption caused by the first power supply circuit 10 supplying power to the power supply chip during the normal operation of the auxiliary power supply system.

[0054] At the same time, the first output end of the power supply circuit is also connected to the first end of the second switch tube D2, so that the output voltage of the second threshold output by the power supply circuit can also be used as the power supply of the conduction circuit of the second switch tube Q2.

[0055] It should be noted that the output voltage of the second threshold output by the power supply circuit may be the same as or different from the output voltage of the first threshold output by the output circuit, and may be specifically adjusted by the number of turns of the wire weight of the correspondingly connected secondary winding.

[0056] The second aspect of the present application also provides an electronic device, including the auxiliary power supply system described in any one of the above embodiments.

[0057] In summary, the present application provides an auxiliary power supply system and electronic device, including a power chip, a first power supply circuit 10, a second power supply circuit 20, a drive circuit 30 and a feedback circuit 40. By setting the first power supply circuit 10 between the external power supply and the power chip, the power supply chip is powered for startup and output of the first drive signal; the drive circuit 30 is set between the power chip and the second power supply circuit 20, so that the drive circuit 30 drives the external power supply and the second power supply circuit 20 to switch between on and off according to the first drive signal, so that the second power supply circuit 20 can convert the input voltage of the external power supply into an output voltage of the first threshold value; the feedback circuit 40 is set at the output end of the second power supply circuit 20, and outputs the second drive signal to the first power supply circuit 10 when the output voltage is abnormal, so that the first power supply circuit 10 drives the power chip to stop outputting the first drive signal, and then the drive circuit stops working, so as to achieve the purpose of protecting the auxiliary source and reducing the loss of the auxiliary source system.

[0058] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. An auxiliary power supply system, characterized in that: It includes a power supply chip, a first power supply circuit, a second power supply circuit, a drive circuit and a feedback circuit; wherein, The first power supply circuit is arranged between an external power supply and the power supply chip, the second power supply circuit is connected to the external power supply, the drive circuit is arranged between the power supply chip and the second power supply circuit, and the feedback circuit is arranged between the second power supply circuit and the first power supply circuit; The first power supply circuit is configured to supply power for the startup operation of the power supply chip when it is turned on, and drive the power supply chip to output a first drive signal. The drive circuit drives the loop between the external power supply and the second power supply circuit to switch between on and off according to the first drive signal, so that the second power supply circuit converts the input voltage of the external power supply into an output voltage of a first threshold value; the feedback circuit is configured to output a second drive signal to the first power supply circuit when the output voltage is lower than the first threshold or higher than the first threshold, and the first power supply circuit drives the power supply chip to stop outputting the first drive signal according to the second drive signal.

2. The auxiliary power supply system according to claim 1, characterized in that: The first power supply circuit includes a soft-start resistor and a first diode, and the input voltage of the external power supply sequentially supplies power to the VCC terminal of the power supply chip through the soft-start resistor and the first diode; wherein the external power supply is connected to the first end of the soft-start resistor and the input end of the second power supply circuit, the second end of the soft-start resistor is connected to the first end of the first diode, and the second end of the first diode is connected to the VCC terminal of the power supply chip.

3. The auxiliary power supply system according to claim 2, characterized in that: The first power supply circuit also includes a comparator, a first resistor, a first capacitor and a first switch tube; wherein the non-inverting end of the comparator is connected to the reference voltage, the inverting end of the comparator is connected to the second end of the soft-start resistor, the first end of the first diode, and the first end of the first resistor, and the output end of the comparator is connected to the ZCS end of the power chip; the first end of the first switch tube is connected to the second end of the first resistor and the first end of the first capacitor, the second end of the first switch tube is connected to the second end of the first capacitor and grounded, and the third end of the first switch tube is connected to the output end of the feedback circuit and the COMP end of the power chip.

4. The auxiliary power supply system according to claim 3, characterized in that: The first switch tube is an NPN transistor; when the second drive signal is at a high level, the first switch tube is turned on, and the output end of the comparator will output a low-level control signal to the ZCS end of the power chip, so that the power chip stops outputting the first drive signal.

5. The auxiliary power supply system according to claim 1, characterized in that: The second power supply circuit includes a transformer, an input loop connected to the primary winding of the transformer, and an output loop connected to the first secondary winding of the voltage generator; wherein the input end of the input loop is connected to the external power supply, the output end of the input loop is connected to the drive circuit, and the output end of the output loop is connected to the input end of the feedback circuit.

6. The auxiliary power supply system according to claim 5, characterized in that: The input loop includes a second capacitor, a third capacitor, a second resistor and a second diode, and the output loop includes a fourth capacitor, a fifth capacitor, a sixth capacitor, a third diode and a third resistor; wherein, The first end of the second capacitor is connected to the first end of the second resistor, the first end of the third capacitor, the first end of the primary winding, and the external power supply, the second end of the second capacitor is grounded, the second end of the second resistor is connected to the second end of the third capacitor and the second end of the second diode; the second end of the primary winding is connected to the first end of the second diode and the driving circuit; The first end of the first secondary winding is connected to the first end of the third diode and the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the first end of the third resistor, the second end of the third resistor is connected to the second end of the third diode, the first end of the fifth capacitor, the first end of the sixth capacitor, the input end of the feedback circuit, and the first output end of the output loop, and the second end of the first secondary winding is connected to the second end of the fifth capacitor, the second end of the sixth capacitor, and the second output end of the output loop.

7. The auxiliary power supply system according to claim 5, characterized in that: The second power supply circuit also includes a power supply loop connected to the second secondary winding of the transformer, and the power supply loop includes a fifth diode and an eighth capacitor; wherein the first end of the fifth diode is connected to the first end of the second secondary winding, the second end of the fifth diode is connected to the first end of the eighth capacitor and the first output end of the power supply loop, and the first output end of the power supply loop is also connected to the second end of the first diode and the VCC end of the power chip; the second end of the second secondary winding is connected to the second end of the eighth capacitor and the second output end of the power supply loop and is grounded.

8. The auxiliary power supply system according to claim 1, characterized in that: The driving circuit includes a second switch tube, a third switch tube, a fourth switch tube, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh capacitor; wherein, the first end of the fourth resistor is connected to the Gate end of the power chip, the second end of the fourth resistor is connected to the third end of the second opening tube and the third end of the third switch tube, the first end of the second switch tube is connected to the second end of the third switch tube and the first end of the sixth resistor, the second end of the second switch tube is connected to the second end of the first diode, the first end of the seventh capacitor, and the VCC end of the power chip, the second end of the third switch tube is connected to the second end of the seventh capacitor and grounded, the second end of the sixth resistor is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the first end of the seventh resistor and the third end of the fourth switch tube, the first end of the fourth switch tube is connected to the second power supply circuit, and the second end of the fourth switch tube is connected to the second end of the seventh resistor and grounded.

9. The auxiliary power supply system according to claim 8, characterized in that: The second switch tube is an NPN transistor, the third switch tube is a PNP transistor, and the fourth switch tube is an NPN MOS tube; wherein, When the first driving signal is at a high level, the third switch tube is turned off, and the second switch tube and the fourth switch tube are turned on in sequence, and drive the second power supply circuit to be fully turned on; When the second driving signal is at a low level, the second switch tube and the fourth switch tube are turned off, the third switch tube is turned on, and drives the second power supply circuit to be partially turned on.

10. An electronic device, characterized in that: The auxiliary power supply system comprises the auxiliary power supply system as described in any one of claims 1 to 9.

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