WO2021128716A1

WO2021128716A1 - Multiplexed output short-circuit protection circuit

Info

Publication number: WO2021128716A1
Application number: PCT/CN2020/091105
Authority: WO
Inventors: 姚斌; 施璐; 李番军; 刘明
Original assignee: 上海派能能源科技股份有限公司
Priority date: 2019-12-26
Filing date: 2020-05-19
Publication date: 2021-07-01

Abstract

A multiplexed output short-circuit protection circuit. The multiplexed output short-circuit protection circuit comprises a power supply module (1), an input winding (2) and a plurality of output windings (3), wherein the power supply module (1) is used for supplying power to the input winding (2), and the output windings (3) are used for coupling a power source signal transmitted by the input winding (2) and outputting isolation power source signals to corresponding loads; a plurality of short-circuit detection circuits (4) used for adjusting an output short-circuit control signal according to the isolation power source signals output by the corresponding output windings (3); and a short-circuit protection circuit (5) used for adjusting, according to short-circuit control signals output by all the short-circuit detection circuits (4), a power supply control signal outputted to the power supply module (1), so as to control a power supply state of the power supply module (1) to the input winding (2). The cost for realizing multiplexed outputting of isolation power sources is effectively reduced, the short-circuit protection for each isolation power source output branch is realized, and the probability of devices in a multiplexed output line of isolation power source signals being burnt out is reduced.

Description

A multi-output short-circuit protection circuit

Technical field

The embodiment of the present invention relates to the field of integrated circuit technology, in particular to a multi-output short-circuit protection circuit.

Background technique

With the continuous development of electronic technology, the degree of integration of equipment in various industries is getting higher and higher. Single boards or devices sometimes need different isolated power supplies to supply power, making the application of integrating multiple isolated power supplies in single boards or devices more and more common .

The current way to realize the output of multiple isolated power signals is to use multiple ready-made isolated power modules, but the isolated power modules are expensive, which undoubtedly increases the technical cost of realizing the output of multiple isolated power signals. In addition, different isolated power signal output branches The connected load is unavoidably short-circuited. The short-circuit process is prone to large abrupt currents. Large short-circuit power consumption will cause the components in the multi-channel isolated power signal output line to burn out and affect the normal operation of the equipment.

Summary of the invention

In view of this, the embodiment of the present invention provides a multi-output short-circuit protection circuit, which effectively reduces the cost of outputting multi-channel isolated power supplies, and at the same time, realizes short-circuit protection for each isolated power output branch, reducing multiple outputs. The probability that the device in the output circuit of the isolated power supply signal will be burnt out.

The embodiment of the present invention provides a multi-output short-circuit protection circuit, including:

A power supply module, an input winding and a plurality of output windings, the power supply module is used to supply power to the input winding, and the output winding is used to couple a power signal transmitted by the input winding and output an isolated power signal to a corresponding load;

A plurality of short-circuit detection circuits for adjusting the output short-circuit control signal according to the isolated power signal output by the corresponding output winding;

The short circuit protection circuit is used to adjust the power supply control signal output to the power supply module according to the short circuit control signals output by all the short circuit detection circuits, so as to control the power supply state of the power supply module to the input winding.

Further, the short-circuit detection circuit includes:

The first switch circuit is configured to adjust the output first switch control signal according to the received isolated power supply signal output by the corresponding output winding;

The second switch circuit is configured to adjust the output short-circuit control signal according to the received first switch control signal.

Further, the first switch circuit includes:

A first voltage dividing device and a second voltage dividing device, the first end of the first voltage dividing device is connected to the isolated power signal, and the second end of the first voltage dividing device is connected to the second voltage dividing device Is electrically connected to the first end, and the second end of the second voltage divider is connected to the first set power signal;

A first switching device, the control terminal of the first switching device is electrically connected to the second terminal of the first voltage dividing device, and the first terminal of the first switching device is connected to the first set power signal, The second terminal of the first switch device is used to output the first switch control signal;

The second switch circuit includes:

A light emitting device, a first end of the light emitting device is connected to a second set power signal, and a second end of the light emitting device is connected to the first switch control signal;

A photosensitive device, the first end of the photosensitive device is connected to the first set power signal, and the second end of the photosensitive device is used to output the short-circuit control signal.

Further, the short-circuit protection circuit includes:

The third switch circuit is configured to adjust the first power supply control signal output to the power supply module according to the received short-circuit control signal.

Further, the third switch circuit includes:

The third switch device, the control terminal of the third switch device is connected to the short circuit control signal, the first terminal of the third switch device is connected to the first set power signal, and the second terminal of the third switch device is connected to the first set power signal. The terminal is electrically connected to the first power supply control terminal of the power supply module and outputs the first power supply control signal.

Further, the third switch circuit further includes:

The first capacitive reactance device, the first end of the first capacitive reactance device is connected to the first set power signal, and the second end of the first capacitive reactance device is electrically connected to the control end of the third switching device. connection.

Further, the short-circuit protection circuit further includes:

The fourth switch circuit is configured to adjust the second power supply control signal output to the power supply module according to the received first power supply control signal.

Further, the fourth switch circuit includes:

A fourth switching device, a control terminal of the fourth switching device is connected to the first power supply control signal, and a first terminal of the fourth switching device is connected to a first set power signal;

A fifth switching device, the control terminal of the fifth switching device is electrically connected to the second terminal of the fourth switching device, and the first terminal of the fifth switching device is electrically connected to the power-on terminal of the power supply module, The second terminal of the fifth switch device is electrically connected to the second power supply control terminal of the power supply module and outputs the second power supply control control signal.

Further, the power supply module is configured to output a power-on signal through the power-on terminal when detecting that the voltage of the second power-supply control signal received by the second power-supply control terminal changes to a set voltage;

The short-circuit protection circuit further includes:

The power-on circuit is configured to power on the second power supply control terminal of the power supply module according to the received power-on signal.

Further, the power-on circuit includes:

A third voltage dividing device, the first end of the third voltage dividing device is connected to the power-on signal, and the second end of the third voltage dividing device is electrically connected to the control end of the fourth switching device;

A second capacitive reactance device, the first end of the second capacitive reactance device is electrically connected to the control end of the fourth switching device, and the second end of the second capacitive reactance device is connected to the first set power supply signal.

The embodiment of the present invention provides a multi-output short-circuit protection circuit. The multi-output short-circuit protection circuit includes a power supply module, an input winding, and a plurality of output windings. The power supply module is used to supply power to the input winding, and the output winding is used to couple the input windings. The transmitted power signal is transmitted and the isolated power signal is output to the corresponding load, that is, the input winding and the output winding are used to form a transformer structure. Compared with directly using multiple isolated power modules to drive different loads, it effectively reduces the cost of implementing multiple isolated power supplies. , And set the multiple output short circuit protection circuit including multiple short circuit detection circuits and a short circuit protection circuit, and the multiple short circuit detection circuits are used to adjust the output short circuit control signal according to the isolated power signal output by the corresponding output winding, and the short circuit protection circuit is used According to the short circuit control signals output by all short circuit detection circuits, the power supply control signal output to the power supply module is adjusted to control the power supply state of the power supply module to the input winding, so that when the load connected to the output winding has a short circuit, the short circuit detection circuit can accurately detect Whether there is a short circuit in the load electrically connected to each output winding, and then control the power supply module to no longer supply power to the input winding when the load electrically connected to any output winding has a short circuit through the short-circuit protection circuit, that is, cut off the power supply line of the power supply module , It realizes the short-circuit protection of each isolated power output branch, and reduces the probability that the components in the multi-channel isolated power signal output circuit are burnt.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present invention or the background art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the background art. Obviously, the drawings in the following description are of the present invention. For the schematic diagrams of some embodiments of the invention, for those of ordinary skill in the art, other solutions can be obtained based on the drawings without creative work.

FIG. 1 is a schematic structural diagram of a multi-output short-circuit protection circuit provided by an embodiment of the present invention;

2 is a schematic diagram of a specific circuit structure of a short-circuit detection circuit provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a specific circuit structure of a short-circuit protection circuit provided by an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for ease of description, the drawings only show a part of the structure related to the present invention, but not all of the structure. Throughout this specification, the same or similar reference numerals represent the same or similar structures, elements or processes. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other if there is no conflict.

FIG. 1 is a schematic structural diagram of a multi-output short-circuit protection circuit provided by an embodiment of the present invention. As shown in Figure 1, the multi-output short circuit protection circuit includes a power supply module 1, an input winding 2 and multiple output windings 3. The power supply module 1 is used to supply power to the input winding 2, and the output winding 3 is used to couple the power transmitted by the input winding 2. Signal and output an isolated power signal to the corresponding load (not shown in Figure 1). The multiple-output short-circuit protection circuit also includes multiple short-circuit detection circuits 4 and a short-circuit protection circuit 5. Figure 1 exemplarily shows that the multiple-output short-circuit protection circuit includes three output windings 3, and the corresponding multiple-output short-circuit protection circuit It includes three short-circuit detection circuits 4, the short-circuit detection circuit 4 is used to adjust the output short-circuit control signal according to the isolated power signal output by the corresponding output winding 3, and the short-circuit protection circuit 5 is used to adjust the short-circuit control signal output by all the short-circuit detection circuits 4 The power supply control signal output to the power supply module 1 is used to control the power supply state of the power supply module 1 to the input winding 2.

Specifically, the power supply module 1 is used to supply power to the input winding 2. The power supply module 1 may be a power supply chip. The power supply module 1 sends a power supply signal to the input winding 2, and the output winding 3 couples the power signal transmitted by the input winding 2 to the corresponding load. To output the isolated power signal, the input winding 2 and the output winding 3 can be set to form a transformer structure. In this way, compared to directly using multiple isolated power modules to drive different loads, no additional isolated power modules are needed, which effectively reduces the realization of multiple output isolated power supplies. the cost of.

In addition, each output winding 3 is configured with a corresponding short-circuit detection circuit 4. If a short-circuit problem occurs in the load electrically connected to any output winding 3, the voltage of the isolated power signal output by the corresponding output winding 3 will change, and short-circuit detection Port B of circuit 4 is connected to the isolated power supply signal output by the output winding 3. The short-circuit detection circuit 4 detects the change in the voltage of the corresponding isolated power supply signal and adjusts the voltage of the output short-circuit control signal. All short-circuit detection circuits 4 are used to output The port A of the short-circuit control signal is short-circuited and then connected to the short-circuit protection circuit 5, so that any change in the voltage of the short-circuit control signal will be detected by the short-circuit protection circuit 5, and the output power supply will be adjusted when the short-circuit protection circuit 5 confirms that there is a short circuit. The control signal is used to control the power supply module 1 to no longer supply power to the input winding 2, so as to realize the short-circuit protection of each isolated power output branch, thereby reducing the probability of the device in the multi-channel isolated power signal output line being burned.

2 is a schematic diagram of a specific circuit structure of a short-circuit detection circuit provided by an embodiment of the present invention. With reference to FIGS. 1 and 2, the short-circuit detection circuit 4 includes a first switch circuit 41 and a second switch circuit 42, the first switch circuit 41 uses In order to adjust the output first switch control signal according to the received isolated power supply signal output by the corresponding output winding 3, the second switch circuit 42 is used to adjust the output short-circuit control signal according to the received first switch control signal.

Specifically, taking the first short-circuit detection circuit 4 as an example, the first switch circuit 41 in the short-circuit detection circuit 4 receives the isolated power signal output by the first output winding 3, and when the load electrically connected to the first output winding 3 occurs When a short circuit occurs, the voltage of the isolated power signal received by the first switch circuit 41 from port B changes, which causes the switch state of the first switch circuit 41 to change, and the level of the first switch control signal output by the first switch circuit 41 is high or low. The change occurs, which in turn causes the switching state of the second switch circuit 42 to change, the level of the short-circuit control signal output by the second switch circuit 42 changes, and the short-circuit protection circuit 5 detects the change in the level of the short-circuit control signal. The power supply module 1 can be controlled to no longer supply power to the input winding 2, so as to realize short-circuit protection.

Optionally, with reference to FIGS. 1 and 2, the first switching circuit 41 includes a first voltage dividing device R1, a second voltage dividing device R2, and a first switching device K1, and the first end of the first voltage dividing device R1 is connected to the isolation Power signal, the second end of the first voltage divider R1 is electrically connected to the first end of the second voltage divider R2, the second end of the second voltage divider R2 is connected to the first set power signal, the first set The power signal can be, for example, a ground signal, and the first voltage dividing device R1 and the second voltage dividing device R2 can be, for example, resistive elements to realize the voltage division of the connected isolated power signal. When the voltage of the isolated power signal changes, the voltage of the isolated power signal is divided. The voltage of the divided voltage signal output by the voltage node also changes.

The control terminal of the first switching device K1, that is, the right port of K1 in FIG. 2, is electrically connected to the second terminal of the first voltage divider R1, and the first terminal of the first switching device K1 is connected to the first set power signal, for example Ground signal, the second terminal of the first switching device K1 is used to output the first switching control signal, the first switching device K1 may be, for example, an insulated gate field effect transistor, that is, a MOS tube, or a triode, that is, a BJT tube. The switching device K1 may also be a diode with a control function as shown in FIG. 2. The diode is turned on or off according to the divided voltage signal input from the right control terminal to realize the level of the first switching control signal output by the first switching circuit 41 High adjustment.

The second switch circuit 42 includes a light emitting device D1 and a photosensitive device T1. The first end of the light emitting device D1 is connected to a second set power signal, such as a VDD signal, and the second end of the light emitting device D1 is connected to the first switch control signal, namely It is electrically connected to the second terminal of the first switching device K1, the first terminal of the photosensitive device T1 is connected to a first set power signal, such as a ground signal, and the second terminal of the photosensitive device T1 is used to output a short circuit control signal. The light-emitting device D1 may be, for example, a light-emitting diode, and the photosensitive device T1 may be, for example, a phototransistor. The light-emitting device D1 controls itself to be turned on or off according to the first switch control signal output by the first switch circuit 41, and emits light when the light-emitting device D1 is turned on. , The photosensitive device T1 is light-sensitive, and the first set power signal connected to the first end of the photosensitive device T1 can be set to the ground signal, then the short-circuit control signal output by the second end of the photosensitive device T1 is a low-level signal, on the contrary If the light-emitting device D1 is turned off and does not emit light, the short-circuit control signal output by the second end of the photosensitive device T1 is a high-level signal, and the short-circuit protection circuit 5 detects the change in the level of the short-circuit control signal and can control the power supply module 1. No longer supply power to the input winding 2, realizing short-circuit protection.

FIG. 3 is a schematic diagram of a specific circuit structure of a short-circuit protection circuit provided by an embodiment of the present invention. 1 to 3, the short-circuit protection circuit 5 includes a third switch circuit 51, and the third switch circuit 51 is used to adjust the first output to the power supply module 1 according to the received short-circuit control signal, that is, the short-circuit control signal input from port A. The power supply control signal, that is, the first power supply control signal output through the first power supply control terminal COM, the port A of the third switch circuit 51 is electrically connected to the short-circuit ports A of all the short-circuit detection circuits 4, and the third switch circuit 51 can be based on the port A. The level of the received short-circuit control signal adjusts the level of the first power supply control signal output to the power supply module 1. The power supply module 1 controls whether to input when the level of the received first power supply control signal is different Winding 2 supplies power.

Optionally, in conjunction with FIGS. 1 to 3, the third switch circuit 51 includes a third switch device K3, the control terminal of the third switch device K3 is connected to the short-circuit control signal, and the first terminal of the third switch device K3 is connected to the first terminal. Setting a power signal, such as a ground signal, the second end of the third switching device K3 is electrically connected to the first power supply control terminal COM of the power supply module 1 and outputs the first power supply control signal.

Specifically, the third switching device K3 may be an insulated gate field effect transistor, that is, a MOS tube, or a triode, that is, a BJT tube. The control terminal of the third switching device K3 controls its own first control signal according to the received short-circuit control signal. Whether the terminal is connected to the second terminal, the first set power signal connected to the first terminal of the third switching device K3 may be, for example, a ground signal. If the third switching device K3 is turned on, the second terminal of the third switching device K3 The first power supply control signal output to the first power supply control terminal COM of the power supply module 1 is a low-level signal. If the third switching device K3 is turned off, the first power supply control signal output from the second terminal of the third switching device K3 to the first power supply control terminal COM of the power supply module 1 is a high-level signal. The level of the short circuit control signal output by the short-circuit detection circuit 4 corresponding to whether the load has a short-circuit condition can be set to be different, thereby controlling the switching state of the third switching device K3 to be different, and the first power supply control terminal COM of the power supply module 1 receives the short-circuit valid Signal (high-level signal or low-level signal) no longer supplies power to the input line group, realizing short-circuit protection.

Optionally, with reference to FIGS. 1 to 3, the third switch circuit 51 further includes a first capacitive reactance device C1, and a first end of the first capacitive reactance device C1 is connected to a first set power signal, such as a ground signal, The second end of the capacitive reactance device C1 is electrically connected to the control end of the third switching device K3.

Specifically, the first capacitive reactance device C1 may be a capacitive element, the first capacitive reactance device C1 is connected to the ground signal GND to the control terminal of the third switching device K3, and the photosensitive device T1 in the short circuit detection circuit 4 is used to output a short circuit control signal. The second terminal may also be connected to the second power supply control terminal POW1 of the power supply module 1, that is, the power supply terminal of the power supply module, through a resistance element. It can be set that when the load connected to the output winding 3 has a short circuit, the corresponding divided voltage signal output to the first switching device K1 is a low-level signal, the first switching device K1 is turned off, and the light-emitting device D1 in the optocoupler does not emit light. The first end and the second end of the photosensitive device T1 are disconnected. When the power is established, that is, the power supply module 1 just starts to supply power to the input winding 2. Since the voltage of the isolated power signal output by the output winding 3 is close to 0V, according to the aforementioned description of the corresponding short-circuit condition, there is no short-circuit when the power is established The situation occurs, but the short-circuit protection will also be triggered by mistake.

The embodiment of the present invention further includes a first capacitive reactance device C1 by setting the third switch circuit 51, the first end of the first capacitive reactance device C1 is connected to the first set power signal, and the second end of the first capacitive reactance device C1 is connected to The control terminal of the third switching device K3 is electrically connected, so that the potential of the control terminal of the third switching device K3 rises slowly, and the short circuit protection will not be directly triggered when the power is established, thereby avoiding the problem of false triggering of the short circuit protection caused by the power establishment. .

Optionally, in conjunction with FIGS. 1 to 3, the short-circuit protection circuit 5 further includes a fourth switch circuit 52, and the fourth switch circuit 52 is configured to output to the first power supply control terminal COM according to the received first power supply control signal The signal adjusts the second power supply control signal output to the power supply module 1. When the load electrically connected to the output winding 3 is short-circuited, the first power supply control signal, that is, the enable signal of the power supply module, can control the power supply module 1 to stop power supply at the same time. , The second power supply control signal output by the fourth switching device K4, that is, the signal output to the second power supply control terminal POW1 of the power supply module 1, can also control the power supply module 1 to stop power supply, and the double short circuit protection mechanism is used to improve the circuit to realize the short circuit protection function Accuracy.

Optionally, with reference to FIGS. 1 to 3, the fourth switch circuit 52 includes a fourth switch device K4 and a fifth switch device K5, the control terminal of the fourth switch device K4 is connected to the first power supply control signal, and the fourth switch device K4 The first end of the fifth switch device K5 is connected to the first set power signal, the control end of the fifth switch device K5 is electrically connected to the second end of the fourth switch device K4, and the first end of the fifth switch device K5 is connected to the power-on of the power supply module 1. The terminal POW is electrically connected, and the second terminal of the fifth switching device K5 is electrically connected with the second power supply control terminal POW1 of the power supply module 1 and outputs a second power supply control control signal.

Specifically, the fourth switching device K4 and the fifth switching device K5 may be insulated gate type field effect transistors, that is, MOS transistors, or triodes, that is, BJT tubes. When the fourth switching device K4 is connected to the first power supply control signal Corresponding to whether the load has a short-circuit condition, the level is different, so that the switching state of the fourth switching device K4 is different, so that the level of the switching control signal connected to the control end of the fifth switching device K5 is also different, the fifth switch The switching state of the device K5 is different. The fifth switching device K5 can be controlled to be turned off when a short circuit exists. The power-on terminal POW of the power supply module 1 is disconnected from the second power supply control terminal POW1, and the second power supply control terminal POW1 is the second power supply The control signal is a low-level signal, and the power supply module 1 stops supplying power.

Optionally, in conjunction with FIGS. 1 to 3, the power supply module 1 is configured to output power-on through the power-on terminal POW when detecting that the voltage of the second power-supply control signal received by the second power-supply control terminal POW1 has changed to a set voltage Signal, the short-circuit protection circuit 5 also includes a power-on circuit 53 for powering on the second power supply control terminal POW1 of the power supply module 1 according to the received power-on signal. The power-on circuit 53 can be set to include a third voltage divider R3 and The second capacitive reactance device C2, the first end of the third voltage dividing device R3 is connected to the power-on signal, the second end of the third voltage dividing device R3 is electrically connected to the control end of the fourth switching device K4, and the second capacitive reactance device The first end of C2 is electrically connected to the control end of the fourth switching device K4, and the second end of the second capacitive reactance device C2 is connected to a first set power signal, such as a ground signal.

Specifically, since the pin corresponding to the second power supply control terminal POW1 of the power supply module 1 has a certain capacitance, when the voltage of the second power supply control signal received by the second power supply control terminal POW1 drops to 0V after the occurrence of a short circuit, the short circuit protection The process will end, and when the power supply module 1 detects that the voltage of the second power supply control signal received by the second power supply control terminal POW1 has changed to the set voltage, for example, 0V, it outputs the power-on signal through the power-on terminal POW, that is, restarts Power on the power supply module 1, and the power-on signal output by the power-on terminal POW passes through the third voltage divider R3 and the second capacitive reactance device C2, so that the fourth switching device K4 that is turned off during short-circuit protection is turned on again, thereby making The fifth switching device K5 is turned on, the power-on terminal POW of the power supply module 1 is connected to the second power supply control terminal POW1 of the power supply module 1, and the second power supply control terminal POW1 receives the high-level second power supply control signal again, and the power supply module 1 can continue to supply power to the input winding 2, that is, the entire circuit can be short-circuit protected when a short circuit occurs to disconnect the power supply line between the power supply module 1 and the input winding 2, and the feedback mechanism inside the power supply module 1 can be used after the power is off The power supply module 1 is automatically powered on to realize hiccup short-circuit protection.

The working principle of the multi-output short-circuit protection circuit will be described as a whole with reference to Figures 1 to 3 below:

The relationship between all short-circuit detection circuits 4 is “OR” off, that is, when any short-circuit detection branch detects a short-circuit condition of the corresponding load, it outputs a short-circuit control signal for controlling the short-circuit protection circuit 5 to perform short-circuit protection.

The short-circuit detection circuit 4 first detects the change in the voltage of the connected isolated power signal through the voltage divider. If the load is short-circuited, the voltage of the isolated power signal will drop. When the voltage of the isolated power signal drops to less than or equal to the set detection voltage, it can Control the first switching device K1 to turn off, and then control the light-emitting device D1 to not emit light, the photosensitive device T1 to output a high level, and then control the third switching device to turn on, and the first power supply control terminal COM of the power supply module receives the low-level first A power supply control signal. At the same time, the fourth switching device K4 is turned off under the action of the low-level first power supply control signal, the fifth switching device K5 is turned off, and POW1 receives the low-level second power supply control signal, and then uses the double short circuit protection mechanism Realize short circuit protection.

In addition, the above multiple output short circuit protection circuit can also be used to achieve overcurrent protection. For example, it can be set to reduce the first voltage divider R1 and the second voltage divider R2 when the current value of the isolated power signal output by the output winding 3 is too large. Using the above-mentioned short-circuit protection principle to achieve over-current protection.

It should be noted that the embodiment of the present invention does not limit whether the switch in the multi-output short-circuit protection circuit is high-level controlled conduction or low-level control conduction. The corresponding switch valid signal can be set according to the function of realizing short-circuit protection. It is a high-level signal or a low-level signal.

The embodiment of the present invention utilizes the input winding and the output winding to form a transformer structure. Compared with directly using multiple isolated power modules to drive different loads, the cost of realizing output multi-channel isolated power supplies is effectively reduced, and the load connected to the output windings is short-circuited. When the short circuit detection circuit can accurately detect whether there is a short circuit in the load electrically connected to each output winding, the short circuit protection circuit can control the power supply module to no longer supply power to the input winding when there is a short circuit in any load electrically connected to the output winding. , That is, cut off the power supply circuit of the power supply module, realize the short-circuit protection of each isolated power output branch, and reduce the probability of the device in the multi-channel isolated power signal output line being burned.

Note that the above are only the preferred embodiments of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and various obvious changes, readjustments and substitutions can be made to those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention. The scope of is determined by the scope of the appended claims.

Claims

A multi-output short-circuit protection circuit, which is characterized in that it comprises:

A power supply module, an input winding and a plurality of output windings, the power supply module is used to supply power to the input winding, and the output winding is used to couple the power signal transmitted by the input winding and output an isolated power signal to a corresponding load;

A plurality of short-circuit detection circuits for adjusting the output short-circuit control signal according to the isolated power signal output by the corresponding output winding;

The short circuit protection circuit is used to adjust the power supply control signal output to the power supply module according to the short circuit control signals output by all the short circuit detection circuits, so as to control the power supply state of the power supply module to the input winding.
The multi-output short-circuit protection circuit according to claim 1, wherein the short-circuit detection circuit comprises:

The first switch circuit is configured to adjust the output first switch control signal according to the received isolated power supply signal output by the corresponding output winding;

The second switch circuit is configured to adjust the output short-circuit control signal according to the received first switch control signal.
The multi-output short-circuit protection circuit according to claim 2, wherein the first switch circuit comprises:

A first voltage dividing device and a second voltage dividing device, the first end of the first voltage dividing device is connected to the isolated power signal, and the second end of the first voltage dividing device is connected to the second voltage dividing device Is electrically connected to the first end, and the second end of the second voltage divider is connected to the first set power signal;

A first switching device, the control terminal of the first switching device is electrically connected to the second terminal of the first voltage dividing device, and the first terminal of the first switching device is connected to the first set power signal, The second terminal of the first switch device is used to output the first switch control signal;

The second switch circuit includes:

A light emitting device, a first end of the light emitting device is connected to a second set power signal, and a second end of the light emitting device is connected to the first switch control signal;

A photosensitive device, the first end of the photosensitive device is connected to the first set power signal, and the second end of the photosensitive device is used to output the short-circuit control signal.
The multi-output short-circuit protection circuit according to claim 1, wherein the short-circuit protection circuit comprises:

The third switch circuit is configured to adjust the first power supply control signal output to the power supply module according to the received short-circuit control signal.
The multi-output short-circuit protection circuit according to claim 4, wherein the third switch circuit comprises:

The third switch device, the control terminal of the third switch device is connected to the short circuit control signal, the first terminal of the third switch device is connected to the first set power signal, and the second terminal of the third switch device is connected to the first set power signal. The terminal is electrically connected to the first power supply control terminal of the power supply module and outputs the first power supply control signal.
The multi-output short-circuit protection circuit according to claim 5, wherein the third switch circuit further comprises:

The first capacitive reactance device, the first end of the first capacitive reactance device is connected to the first set power signal, and the second end of the first capacitive reactance device is electrically connected to the control end of the third switching device. connection.
The multi-output short-circuit protection circuit according to any one of claims 4-6, wherein the short-circuit protection circuit further comprises:

The fourth switch circuit is used to adjust the second power supply control signal output to the power supply module according to the received first power supply control signal.
The multi-output short-circuit protection circuit according to claim 7, wherein the fourth switch circuit comprises:

A fourth switching device, a control terminal of the fourth switching device is connected to the first power supply control signal, and a first terminal of the fourth switching device is connected to a first set power signal;

A fifth switching device, the control terminal of the fifth switching device is electrically connected to the second terminal of the fourth switching device, and the first terminal of the fifth switching device is electrically connected to the power-on terminal of the power supply module, The second terminal of the fifth switch device is electrically connected to the second power supply control terminal of the power supply module and outputs the second power supply control control signal.
The multi-output short-circuit protection circuit according to claim 8, wherein the power supply module is configured to detect that the voltage of the second power supply control signal received by the second power supply control terminal changes to a set voltage , Output a power-on signal through the power-on terminal;

The short-circuit protection circuit further includes:

The power-on circuit is configured to power on the second power supply control terminal of the power supply module according to the received power-on signal.
The multi-output short-circuit protection circuit according to claim 9, wherein the power-on circuit comprises:

A third voltage dividing device, the first end of the third voltage dividing device is connected to the power-on signal, and the second end of the third voltage dividing device is electrically connected to the control end of the fourth switching device;

A second capacitive reactance device, the first end of the second capacitive reactance device is electrically connected to the control end of the fourth switching device, and the second end of the second capacitive reactance device is connected to the first set power supply signal.