DCDC conversion module

Abstract

The utility model relates to a DCDC conversion module. Comprising an input filter circuit, the input end of the input filter circuit is connected with the input end anode of a power supply, the output end of the input filter circuit is connected with the input end cathode of the power supply, and the input end cathode of the power supply is grounded; the power conversion circuit comprises a transformer primary coil, an over-current short-circuit protection circuit and a field effect control circuit, the dotted terminal of the transformer primary coil is connected with the input end of the input filter circuit, and the non-dotted terminal of the transformer primary coil is connected with the input end of the over-current short-circuit protection circuit. The first output end of the overcurrent short-circuit protection circuit is connected with the first input end of the field effect control circuit, and the output end of the field effect control circuit is grounded; the input end of the under-voltage protection circuit is connected with the positive electrode of the input end of the power supply. According to the invention, the input voltage signal is converted into the required output voltage signal.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of power supply technology, and in particular to a DCDC conversion module. Background Art

[0002] With the rapid development of modern science and technology, the switching power supply modules supporting the control of various electronic equipment are also constantly improving.

[0003] In the related art, as the functions of the switching power supply module continue to increase, its size is getting smaller and smaller; however, due to the increasing number of functions, its power conversion efficiency is always not high enough, which affects the stability of the switching power supply module.

[0004] Therefore, designing a small switching power supply module with high power conversion efficiency has become an urgent problem to be solved.

[0005] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0007] The purpose of the embodiments of the present application is to provide a DCDC conversion module, thereby overcoming one or more problems caused by the limitations and defects of the related art at least to a certain extent.

[0008] A DCDC conversion module provided according to an embodiment of the present application includes:

[0009] An input filter circuit, wherein the input end of the input filter circuit is connected to the positive electrode of the input end of the power supply, and the output end of the input filter circuit is connected to the negative electrode of the input end of the power supply; wherein the negative electrode of the input end of the power supply is grounded;

[0010] A power conversion circuit, comprising a transformer primary coil, an overcurrent short-circuit protection circuit and a field effect control circuit, wherein the same-name end of the transformer primary coil is connected to the input end of the input filter circuit, the non-same-name end of the transformer primary coil is connected to the input end of the overcurrent short-circuit protection circuit, the first output end of the overcurrent short-circuit protection circuit is connected to the first input end of the field effect control circuit, and the output end of the field effect control circuit is grounded;

[0011] An undervoltage protection circuit and a pulse width control circuit, wherein the input end of the undervoltage protection circuit is connected to the positive electrode of the input end of the power supply, the first output end of the undervoltage protection circuit is connected to the first input end of the pulse width control circuit, the second input end of the pulse width control circuit is connected to the positive electrode of the input end of the power supply, the first output end of the pulse width control circuit is connected to the second input end of the field effect control circuit, and the third input end of the pulse width control circuit is connected to the second output end of the overcurrent short circuit protection circuit; wherein the second output end of the undervoltage protection circuit and the second output end of the pulse width control circuit are grounded respectively;

[0012] A synchronous rectification circuit, comprising a transformer secondary coil and a field effect rectification circuit, wherein the same-name end of the transformer secondary coil is connected to the input end of the field effect rectification circuit, and the non-same-name end of the transformer secondary coil is connected to the first output end of the field effect rectification circuit;

[0013] An output filter circuit, wherein the input end of the output filter circuit is connected to the same-name end of the secondary coil of the transformer, the first output end of the output filter circuit is connected to the positive output end of the power supply, and the second output end of the output filter circuit is connected to the negative output end of the power supply;

[0014] an anti-interference branch, wherein the input end of the anti-interference branch is connected to the second output end of the field effect rectifier circuit, and the output end of the anti-interference branch is grounded;

[0015] And, an isolated sampling circuit, wherein the first input terminal of the isolated sampling circuit is connected to the positive input terminal of the power supply, the second input terminal of the isolated sampling circuit is connected to the negative input terminal of the power supply, the first output terminal of the isolated sampling circuit is connected to the fourth input terminal of the pulse width control circuit, and the second output terminal of the isolated sampling circuit is grounded.

[0016] In one embodiment of the present application, the input filter circuit includes: a first capacitor component, a first end of the first capacitor component is connected to the positive input terminal of the power supply, and a second end of the first capacitor component is connected to the negative input terminal of the power supply.

[0017] In one embodiment of the present application, the first capacitor component includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a tenth capacitor, wherein a first end of the first capacitor, a first end of the second capacitor, a first end of the third capacitor, a first end of the fourth capacitor, a first end of the fifth capacitor, a first end of the sixth capacitor, a first end of the seventh capacitor, a first end of the eighth capacitor, a first end of the ninth capacitor and a first end of the tenth capacitor are respectively connected to the positive electrode of the input terminal of the power supply, and a second end of the first capacitor, a second end of the second capacitor, a second end of the third capacitor, a second end of the fourth capacitor, a second end of the fifth capacitor, a second end of the sixth capacitor, a second end of the seventh capacitor, a second end of the eighth capacitor, a second end of the ninth capacitor and a second end of the tenth capacitor are respectively connected to the negative electrode of the input terminal of the power supply.

[0018] In one embodiment of the present application, the overcurrent short-circuit protection circuit comprises: a primary coil of a current transformer and a secondary coil of a current transformer, the same-name end of the primary coil of the current transformer is connected to the non-same-name end of the primary coil of the transformer, and the same-name end of the secondary coil of the current transformer is grounded;

[0019] The field effect control circuit comprises: a first field effect tube, an eleventh capacitor and a first diode, wherein the source of the first field effect tube, the first end of the eleventh capacitor and the cathode of the first diode are respectively connected to the non-same-name ends of the primary coil of the current transformer; wherein the drain of the first field effect tube and the anode of the first diode are respectively grounded;

[0020] a second field effect transistor and a second diode, wherein the source of the second field effect transistor and the anode of the second diode are respectively connected to the second end of the eleventh capacitor, and the drain of the second field effect transistor and the cathode of the second diode are respectively grounded;

[0021] And, a first resistor, a second resistor, a third diode, a fourth diode and a twelfth capacitor, the first end of the first resistor is connected to the control electrode of the first field effect transistor, the first end of the second resistor, the anode of the third diode, the anode of the fourth diode and the first end of the twelfth capacitor are respectively connected to the control electrode of the second field effect transistor; wherein the second end of the first resistor, the second end of the second resistor, the cathode of the third diode and the cathode of the fourth diode are respectively grounded.

[0022] In one embodiment of the present application, the undervoltage protection circuit includes:

[0023] a third resistor and a first voltage stabilizing diode, wherein a first end of the third resistor and a cathode of the first voltage stabilizing diode are respectively connected to a positive electrode of an input end of the power supply;

[0024] a fifth diode, a sixth diode, a first triode, a fourth resistor, a fifth resistor and a thirteenth capacitor, wherein the anode of the fifth diode, the anode of the sixth diode, the first end of the fourth resistor, the first end of the fifth resistor, the first end of the thirteenth capacitor and the second end of the third resistor are respectively connected to the collector of the first triode; wherein the emitter of the first triode, the second end of the fourth resistor and the second end of the thirteenth capacitor are respectively grounded, and the cathode of the fifth diode and the cathode of the sixth diode are respectively connected to the grounding prohibition terminal;

[0025] And, a seventh diode, an eighth diode, a sixth resistor and a seventh resistor, the anode of the seventh diode and the anode of the eighth diode are respectively connected to the anode of the first voltage zener diode, the cathode of the seventh diode and the cathode of the eighth diode are respectively connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the base of the first transistor, and the first end of the seventh resistor is connected to the first end of the sixth resistor; wherein the second end of the seventh resistor is grounded.

[0026] In one embodiment of the present application, the pulse width control circuit includes:

[0027] A chip, comprising a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin, an eighth pin, a ninth pin, a tenth pin, an eleventh pin, a twelfth pin, a thirteenth pin, a fourteenth pin, a fifteenth pin and a sixteenth pin; the first pin is connected to the positive electrode of the input end of the power supply, the eighth pin is connected to the control electrode of the first field effect transistor, the ninth pin is connected to the second end of the twelfth capacitor, the tenth pin and the eleventh pin are grounded respectively, and the sixteenth pin is connected to the second end of the fifth resistor;

[0028] an eighth resistor, a fourteenth capacitor and a fifteenth capacitor, wherein a first end of the eighth resistor and a first end of the fourteenth capacitor are respectively connected to the first pin, a second end of the eighth resistor and a first end of the fifteenth capacitor are respectively connected to the second pin, and a second end of the fourteenth capacitor and a second end of the fifteenth capacitor are respectively grounded;

[0029] a sixteenth capacitor, a first end of the sixteenth capacitor being connected to the third pin, and a second end of the sixteenth capacitor being grounded;

[0030] a ninth resistor and a seventeenth capacitor, wherein a first end of the ninth resistor and a first end of the seventeenth capacitor are respectively connected to the fourth pin, and a second end of the ninth resistor and a second end of the seventeenth capacitor are respectively grounded;

[0031] a tenth resistor, a first end of the tenth resistor being connected to the fifth pin, and a second end of the tenth resistor being grounded;

[0032] an eighteenth capacitor, a first end of the eighteenth capacitor being connected to the sixth pin, and a second end of the eighteenth capacitor being grounded;

[0033] a nineteenth capacitor and a twenty-third capacitor, wherein a first end of the nineteenth capacitor and a first end of the twenty-third capacitor are respectively connected to the seventh pin, and a second end of the nineteenth capacitor and a second end of the twenty-third capacitor are respectively grounded;

[0034] A twenty-first capacitor, a first end of the twenty-first capacitor is connected to the twelfth pin, and a second end of the twenty-first capacitor is grounded;

[0035] a twenty-second capacitor and an eleventh resistor, wherein a first end of the twenty-second capacitor and a first end of the eleventh resistor are respectively connected to the sixth pin, and a second end of the twenty-second capacitor and a second end of the eleventh resistor are respectively connected to the thirteenth pin;

[0036] a twelfth resistor, a first end of the twelfth resistor being connected to the fourteenth pin, and a second end of the twelfth resistor being grounded;

[0037] a thirteenth resistor, a first end of the thirteenth resistor being connected to the fifteenth pin, and a second end of the thirteenth resistor being grounded;

[0038] a twenty-third capacitor, a fourteenth resistor and a fifteenth resistor, wherein a first end of the twenty-third capacitor is connected to a first end of the fourteenth resistor, a second end of the fourteenth resistor is connected to a first end of the fifteenth resistor, and a second end of the fifteenth resistor is connected to the fourth pin; wherein a second end of the twenty-third capacitor is grounded;

[0039] A ninth diode, a tenth diode and a sixteenth resistor, wherein the anode of the ninth diode and the anode of the tenth diode are respectively connected to the first end of the sixteenth resistor, and the second end of the sixteenth resistor is grounded; wherein the anode of the tenth diode is connected to the non-same-name end of the secondary coil of the current transformer;

[0040] a seventeenth resistor, an eighteenth resistor, a nineteenth resistor and a twentieth resistor, wherein the first end of the seventeenth resistor, the first end of the eighteenth resistor and the first end of the nineteenth resistor are respectively connected to the first end of the twentieth resistor, the second end of the seventeenth resistor, the second end of the eighteenth resistor and the second end of the nineteenth resistor are respectively grounded, and the second end of the twentieth resistor is connected to the third pin; wherein the cathode of the ninth diode and the cathode of the tenth diode are respectively connected to the first end of the twentieth resistor;

[0041] In addition, the twenty-fourth capacitor, the twenty-first resistor, the eleventh diode, the twelfth diode and the secondary winding of the energy storage coil, the anode of the eleventh diode, the anode of the twelfth diode and the first end of the twenty-first resistor are respectively connected to the first end of the secondary winding of the energy storage coil, the cathode of the eleventh diode and the cathode of the twelfth diode are respectively connected to the seventh pin, the second end of the twenty-first resistor is connected to the first end of the twenty-fourth capacitor, and the second end of the twenty-fourth capacitor and the second end of the secondary winding of the energy storage coil are respectively grounded.

[0042] In one embodiment of the present application, the field effect rectifier circuit includes:

[0043] a third field effect tube and a thirteenth diode, wherein the source of the third field effect tube and the cathode of the thirteenth diode are respectively connected to the same-named ends of the secondary coil of the transformer, and the anode of the thirteenth diode is connected to the drain of the third field effect tube;

[0044] A second triode and a third triode, wherein the emitter of the second triode and the emitter of the third triode are respectively connected to the control electrode of the third field effect tube, the collector of the second triode is connected to the non-same-name end of the secondary coil of the transformer, and the collector of the third triode is connected to the drain of the third field effect tube;

[0045] a twenty-second resistor, a twenty-fifth capacitor, a fourteenth diode and a fifteenth diode, wherein the first end of the twenty-second resistor, the first end of the twenty-fifth capacitor, the anode of the fourteenth diode and the anode of the fifteenth diode are respectively connected to the base of the second transistor, and the second end of the twenty-second resistor, the second end of the twenty-fifth capacitor, the cathode of the fourteenth diode and the cathode of the fifteenth diode are respectively connected to the non-same-name ends of the secondary coil of the transformer;

[0046] a second voltage-stabilizing diode, wherein the anode of the second voltage-stabilizing diode is connected to the collector of the third transistor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the base of the second transistor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the first end of the twenty-second resistor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the first end of the twenty-fifth capacitor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the anode of the fourteenth diode, and the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the anode of the fifteenth diode;

[0047] A fourth field effect transistor and a sixteenth diode, wherein the source of the fourth field effect transistor and the cathode of the sixteenth diode are respectively connected to non-same-name ends of the secondary winding of the transformer;

[0048] In addition, the seventeenth diode, the eighteenth diode, the twenty-third resistor, the twenty-sixth capacitor, the fourth transistor, the fifth transistor and the third voltage-stabilizing diode, the cathode of the seventeenth diode, the cathode of the eighteenth diode, the first end of the twenty-third resistor, the first end of the twenty-sixth capacitor and the collector of the fourth transistor are respectively connected to the same-name ends of the secondary winding of the transformer, the anode of the seventeenth diode, the anode of the eighteenth diode, the second end of the twenty-third resistor, the second end of the twenty-sixth capacitor, the base of the fourth transistor and the base of the fifth transistor are respectively connected to the cathode of the third voltage-stabilizing diode, and the emitter of the fourth transistor and the emitter of the fifth transistor are respectively connected to the control electrode of the fourth field-effect transistor.

[0049] In one embodiment of the present application, the output filter circuit includes:

[0050] A second capacitor component, a primary winding package of an energy storage inductor, a twenty-fourth resistor, a twenty-seventh capacitor and a nineteenth diode, wherein the first end of the second capacitor component is connected to the first end of the primary winding package of the energy storage inductor, the first end of the second capacitor component is connected to the positive output terminal of the power supply, the second end of the second capacitor component is connected to the negative output terminal of the power supply, the anode of the nineteenth diode is connected to the second end of the primary winding package of the energy storage inductor, the anode of the nineteenth diode is connected to the same-name end of the secondary winding package of the transformer, the first end of the twenty-seventh capacitor and the first end of the twenty-fourth resistor are respectively connected to the cathode of the nineteenth diode, and the second end of the twenty-seventh capacitor is connected to the second end of the twenty-fourth resistor.

[0051] In one embodiment of the present application, the isolation sampling circuit includes:

[0052] a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, and a twenty-tenth diode, wherein a first end of the twenty-fifth resistor, a first end of the twenty-sixth resistor, a first end of the twenty-seventh resistor, a first end of the twenty-eighth resistor, a first end of the twenty-ninth resistor, and a cathode of the twenty-tenth diode are respectively connected to the positive electrode of the output terminal of the power supply, and an anode of the 20th diode is connected to the second end of the 29th resistor;

[0053] a 30th resistor, a 31st resistor, a reference voltage controller, and a 28th capacitor, wherein a first end of the 30th resistor, a first end of the 31st resistor, an anode of the reference voltage controller, and a first end of the 28th capacitor are respectively connected to the negative electrode of the output terminal of the power supply, a second end of the 30th resistor, a second end of the 31st resistor, a second end of the 26th resistor, and a second end of the 27th resistor are respectively connected to the reference terminal of the reference voltage controller, and a second end of the 28th capacitor is connected to the second end of the 29th resistor;

[0054] a twenty-ninth capacitor and a thirty-second resistor, wherein a first end of the twenty-ninth capacitor is connected to a second end of the twenty-fifth resistor, and a second end of the twenty-ninth capacitor and a first end of the thirty-second resistor are respectively connected to a reference end of the reference voltage controller;

[0055] And, a 30th capacitor, a 33rd resistor, a 21st diode and an optocoupler, the first end of the 30th capacitor, the first end of the 33rd resistor, the cathode of the reference voltage controller and the anode of the 21st diode are respectively connected to the cathode of the optocoupler, the second end of the 33rd resistor is connected to the second end of the 28th resistor, the cathode of the 21st diode is connected to the second end of the 29th resistor, and the second end of the 30th capacitor is connected to the second end of the 32nd resistor; wherein the anode of the optocoupler is connected to the second end of the 28th resistor, the collector of the optocoupler is connected to the 13th pin in the pulse width control circuit, and the emitter of the optocoupler is grounded.

[0056] In one embodiment of the present application, the anti-interference branch includes a thirty-first capacitor, the anode of the third voltage-stabilizing diode, the collector of the fifth transistor, the anode of the sixteenth diode and the drain of the fourth field-effect transistor are respectively connected to the first end of the thirty-first capacitor, and the second end of the thirty-first capacitor is grounded.

[0057] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0058] In the embodiment of the present application, after the input voltage signal is connected through the above-mentioned DCDC conversion module, the overall circuit of the DCDC conversion module is protected by the undervoltage protection circuit, and then it is filtered by the input filter circuit, and the pulse width control circuit controls the power conversion circuit to perform power conversion, and the synchronous rectification circuit performs synchronous rectification and outputs the rectified filter signal, and then samples through the isolation sampling circuit, and feeds back to the pulse width control circuit for voltage regulation control, forming a closed-loop control circuit to complete the conversion of the input voltage signal, and finally isolates and outputs the input voltage signal after voltage regulation to generate the required output voltage signal. Through the DCDC conversion module, the present application can realize the conversion of the input voltage signal into the required output voltage signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0060] Figure 1 A circuit diagram of a DCDC conversion module in an exemplary embodiment of the present application is shown;

[0061] Figure 2 A schematic diagram showing pins on a chip in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0062] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0063] In addition, the drawings are only schematic illustrations of the embodiments of the present application and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and thus their repeated description will be omitted.

[0064] This example embodiment provides a DCDC conversion module. Figure 1 As shown in , the module may include: an input filter circuit, a power conversion circuit, an undervoltage protection circuit, a pulse width control circuit, a synchronous rectification circuit, an output filter circuit, an anti-interference branch and an isolation sampling circuit.

[0065] Wherein, an input filter circuit, the input end of the input filter circuit is connected to the positive pole of the input end of the power supply, and the output end of the input filter circuit is connected to the negative pole of the input end of the power supply; wherein the negative pole of the input end of the power supply is grounded; a power conversion circuit, including a transformer primary winding, an overcurrent short-circuit protection circuit and a field effect control circuit, the same-name end of the transformer primary winding is connected to the input end of the input filter circuit, the non-same-name end of the transformer primary winding is connected to the input end of the overcurrent short-circuit protection circuit, the first output end of the overcurrent short-circuit protection circuit is connected to the first input end of the field effect control circuit, and the output end of the field effect control circuit is grounded; an undervoltage protection circuit and a pulse width control circuit, the input end of the undervoltage protection circuit is connected to the positive pole of the input end of the power supply, the first output end of the undervoltage protection circuit is connected to the first input end of the pulse width control circuit, the second input end of the pulse width control circuit is connected to the positive pole of the input end of the power supply, the first output end of the pulse width control circuit is connected to the second input end of the field effect control circuit, the third input end of the pulse width control circuit is connected to the second input end of the overcurrent short-circuit protection circuit The output end is connected; wherein the second output end of the undervoltage protection circuit and the second output end of the pulse width control circuit are grounded respectively; a synchronous rectification circuit, including a transformer secondary coil and a field effect rectification circuit, the same-name end of the transformer secondary coil is connected to the input end of the field effect rectification circuit, and the non-same-name end of the transformer secondary coil is connected to the first output end of the field effect rectification circuit; an output filter circuit, the input end of the output filter circuit is connected to the same-name end of the transformer secondary coil, the first output end of the output filter circuit is connected to the positive output end of the power supply, and the second output end of the output filter circuit is connected to the negative output end of the power supply; an anti-interference branch, the input end of the anti-interference branch is connected to the second output end of the field effect rectification circuit, and the output end of the anti-interference branch is grounded; and an isolation sampling circuit, the first input end of the isolation sampling circuit is connected to the positive input end of the power supply, the second input end of the isolation sampling circuit is connected to the negative input end of the power supply, the first output end of the isolation sampling circuit is connected to the fourth input end of the pulse width control circuit, and the second output end of the isolation sampling circuit is grounded.

[0066] It can be understood that the input end of the input filter circuit is connected to the positive input end (VIN+) of the power supply, the output end of the input filter circuit is connected to the negative input end (VIN-) of the power supply, and the output end of the input filter circuit is grounded. The power supply is turned on through the input filter circuit to input the input voltage signal through the positive input end (VIN+) of the power supply and the negative input end (VIN-) of the power supply to the input filter circuit. The input voltage signal is filtered by the input filter circuit to obtain a filtered input voltage signal.

[0067] At the same time, the input end of the undervoltage protection circuit is connected to the positive pole of the input end of the power supply, and the second output end of the undervoltage protection circuit is grounded, so that the undervoltage protection circuit is connected to the power supply. After the power supply is turned on through the undervoltage protection circuit, the input voltage signal is input to the undervoltage protection circuit. When the input voltage signal is too small, the undervoltage protection circuit converts the input voltage signal into a first control signal to control the pulse width control circuit to stop working; when the input voltage signal is normal, the undervoltage protection circuit converts the input voltage signal into a second control signal to control the pulse width circuit to work normally. Therefore, the undervoltage protection circuit can realize undervoltage protection of the DCDC conversion module.

[0068] The second input terminal of the pulse width control circuit is connected to the positive input terminal of the power supply, and the second output terminal of the pulse width control circuit is grounded, so that the pulse width control circuit is connected to the power supply. When the power supply is turned on by the pulse width control circuit, the input voltage signal is input to the pulse width control circuit, which is equivalent to providing the pulse width control circuit with a working voltage, so that the pulse width control circuit can control the power conversion circuit to work.

[0069] The first output terminal of the pulse width control circuit is connected to the second input terminal of the field effect control circuit to realize the connection between the pulse width control circuit and the field effect control circuit. Since the power conversion circuit includes the field effect control circuit, the connection between the pulse width control circuit and the power conversion circuit is realized. The power conversion circuit is used to perform power conversion on the input voltage signal to obtain the input voltage signal after power conversion. When the pulse width control circuit controls the power conversion circuit to perform power conversion, the input voltage signal after power conversion is output to the synchronous rectification circuit for rectification processing, and then filtered through the output filter circuit.

[0070] It should be noted that the input voltage signal after power conversion is output to the transformer secondary coil in the synchronous rectification circuit through the transformer primary coil in the power conversion circuit, and then the input voltage signal after power conversion is rectified by the field effect rectification circuit to obtain the rectified input voltage signal. After that, the rectified input voltage signal is output to the output filter circuit for filtering through the field effect rectification circuit to obtain the rectified filtered signal. Among them, the transformer T1 includes the transformer primary coil and the transformer secondary coil.

[0071] The first output terminal of the output filter circuit is connected to the positive output terminal (V0+) of the power supply, and the second output terminal of the output filter circuit is connected to the negative output terminal (V0-) of the power supply, so that the rectified and filtered signal can be output.

[0072] The first input terminal of the isolated sampling circuit is connected to the positive input terminal of the power supply, and the second input terminal of the isolated sampling circuit is connected to the negative input terminal of the power supply, so that the isolated sampling circuit is connected to the power supply, so as to collect the rectified and filtered signal output by the output filter circuit through the isolated sampling circuit to generate a control signal. The first output terminal of the isolated sampling circuit is connected to the fourth input terminal of the pulse width control circuit to realize the connection between the isolated sampling circuit and the pulse width control circuit, so as to output the control signal to the pulse width control circuit through the isolated sampling circuit to control the output voltage signal.

[0073] In the embodiment of the present application, after the input voltage signal is connected through the above-mentioned DCDC conversion module, the overall circuit of the DCDC conversion module is protected by the undervoltage protection circuit, and then it is filtered by the input filter circuit, and the pulse width control circuit controls the power conversion circuit to perform power conversion, and the synchronous rectification circuit performs synchronous rectification and outputs the rectified filter signal, and then samples through the isolation sampling circuit, and feeds back to the pulse width control circuit for voltage regulation control, forming a closed-loop control circuit to complete the conversion of the input voltage signal, and finally isolates and outputs the input voltage signal after voltage regulation to generate the required output voltage signal. Through the DCDC conversion module, the present application can realize the conversion of the input voltage signal into the required output voltage signal.

[0074] Next, we will refer to Figure 1 to Figure 2 The various parts of the above-mentioned DCDC conversion module in this exemplary embodiment are described in more detail.

[0075] In one embodiment, reference Figure 1 The input filter circuit includes: a first capacitor component, a first end of the first capacitor component is connected to the positive input terminal of the power supply, and a second end of the first capacitor component is connected to the negative input terminal of the power supply.

[0076] For further reference, Figure 1The first capacitor component includes: a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9 and a tenth capacitor C10, a first end of the first capacitor C1, a first end of the second capacitor C2, a first end of the third capacitor C3, a first end of the fourth capacitor C4, a first end of the fifth capacitor C5, a first end of the sixth capacitor C6, a first end of the seventh capacitor C7, a first end of the eighth capacitor C8, a first end of the ninth capacitor C9 and a first end of the tenth capacitor C10 are respectively connected to the positive electrode of the input terminal of the power supply, and a second end of the first capacitor C1, a second end of the second capacitor C2, a second end of the third capacitor C3, a second end of the fourth capacitor C4, a second end of the fifth capacitor C5, a second end of the sixth capacitor C6, a second end of the seventh capacitor C7, a second end of the eighth capacitor C8, a second end of the ninth capacitor C9 and a second end of the tenth capacitor C10 are respectively connected to the negative electrode of the input terminal of the power supply.

[0077] It can be understood that the input filter circuit includes a first capacitor component, and the first capacitor component includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9 and a tenth capacitor C10 connected in parallel. By directly connecting the above ten capacitors in parallel to the power supply, the input voltage signal is filtered to obtain a filtered input voltage signal. In addition, applying the electromagnetic compatibility principle, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9 and the tenth capacitor C10 are all small-capacity chip capacitors. These ten small-capacity chip capacitors are used to filter the input voltage signal, so that the electromagnetic compatibility performance is strong and the filtering effect is good.

[0078] In one embodiment, reference Figure 1 , the over-current short-circuit protection circuit comprises: a primary coil of a current transformer and a secondary coil of a current transformer, the same-name end of the primary coil of the current transformer is connected to the non-same-name end of the primary coil of the transformer, and the same-name end of the secondary coil of the current transformer is grounded;

[0079] The field effect control circuit comprises: a first field effect transistor Q1, an eleventh capacitor C11 and a first diode D1, wherein the source of the first field effect transistor Q1, the first end of the eleventh capacitor C11 and the cathode of the first diode D1 are respectively connected to the non-same-name ends of the primary coil of the current transformer; wherein the drain of the first field effect transistor Q1 and the anode of the first diode D1 are respectively grounded;

[0080] a second field effect transistor Q2 and a second diode D2, wherein the source of the second field effect transistor Q2 and the anode of the second diode D2 are respectively connected to the second end of the eleventh capacitor C11, and the drain of the second field effect transistor Q2 and the cathode of the second diode D2 are respectively grounded;

[0081] In addition, a first resistor R1, a second resistor R2, a third diode D3, a fourth diode D4 and a twelfth capacitor C12, the first end of the first resistor R1 is connected to the control electrode of the first field effect transistor Q1, the first end of the second resistor R2, the anode of the third diode D3, the anode of the fourth diode D4 and the first end of the twelfth capacitor C12 are respectively connected to the control electrode of the second field effect transistor Q2; wherein the second end of the first resistor R1, the second end of the second resistor R2, the cathode of the third diode D3 and the cathode of the fourth diode D4 are respectively grounded.

[0082] It is understandable that the overcurrent short-circuit protection circuit does not use resistor sampling, but directly uses the current transformer T2 for isolated sampling, avoiding the effects of resistor heating, energy consumption, temperature drift, etc. The 100:1 ratio is adopted to improve the sampling accuracy and enhance the stability control of the output voltage signal. The overcurrent short-circuit protection circuit is more reliable, and the specific control is that the pulse width control circuit automatically judges, processes and controls after receiving the current signal output by the overcurrent short-circuit protection circuit. Among them, the current transformer T2 includes a current transformer primary coil and a current transformer secondary coil. The current signal is isolated and sampled by the current transformer T2, and the sampled current signal BI is coupled to the anode of the ninth diode D9 and the anode of the tenth diode D10 in the pulse width control circuit, and then coupled to the third pin CS1 of the chip U1 through the twentieth resistor R20, and the current signal is regulated and controlled and protected against overcurrent short circuit, etc. The size of the current signal is adjusted and set by the seventeenth resistor R17, the eighteenth resistor R18, and the nineteenth resistor R19.

[0083] Through the field effect control circuit, power conversion can be performed on the input voltage signal to obtain the input voltage signal after power conversion.

[0084] In one embodiment, reference Figure 1 , the undervoltage protection circuit includes:

[0085] A third resistor R3 and a first voltage stabilizing diode DW1, wherein a first end of the third resistor R3 and a cathode of the first voltage stabilizing diode DW1 are respectively connected to a positive electrode of an input terminal of a power supply;

[0086] a fifth diode D5, a sixth diode D6, a first triode N1, a fourth resistor R4, a fifth resistor R5 and a thirteenth capacitor C13, wherein an anode of the fifth diode D5, an anode of the sixth diode D6, a first end of the fourth resistor R4, a first end of the fifth resistor R5, a first end of the thirteenth capacitor C13 and a second end of the third resistor R3 are respectively connected to the collector of the first triode N1; wherein an emitter of the first triode N1, a second end of the fourth resistor R4 and a second end of the thirteenth capacitor C13 are respectively grounded, and a cathode of the fifth diode D5 and a cathode of the sixth diode D6 are respectively connected to the ground prohibition terminal REM (L);

[0087] In addition, the seventh diode D7, the eighth diode D8, the sixth resistor R6 and the seventh resistor R7, the anode of the seventh diode D7 and the anode of the eighth diode D8 are respectively connected to the anode of the first voltage zener diode DW1, the cathode of the seventh diode D7 and the cathode of the eighth diode D8 are respectively connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected to the base of the first transistor N1, and the first end of the seventh resistor R7 is connected to the first end of the sixth resistor R6; wherein the second end of the seventh resistor R7 is grounded.

[0088] It can be understood that the present application controls the change of the input voltage signal through the undervoltage protection circuit and outputs it to the pulse width control circuit for automatic adjustment. Specifically, when the power is turned on through the undervoltage protection circuit, the input voltage signal is input into the undervoltage protection circuit. When the size of the input voltage signal is too small, the undervoltage protection circuit converts the input voltage signal into a first control signal to control the pulse width control circuit to stop working; when the size of the input voltage signal is normal, the undervoltage protection circuit converts the input voltage signal into a second control signal to control the normal operation of the pulse width circuit. The present application has a ground prohibition terminal REM (L), which can control the on and off of the output voltage signal, can finely adjust the output voltage signal of the DCDC conversion module from the outside, and can also control the switching frequency from the external input. Therefore, the undervoltage protection and prohibition control of the DCDC conversion module can be realized through the undervoltage protection circuit.

[0089] In one embodiment, participating Figure 1 and Figure 2 As shown, the pulse width control circuit includes:

[0090] The chip U1 includes a first pin VIN, a second pin RAMP, a third pin CS1, a fourth pin CS2, a fifth pin DEADTIME, a sixth pin REF, a seventh pin VCC, an eighth pin OUTA, a ninth pin OUTB, a tenth pin PGND, an eleventh pin AGND, a twelfth pin SS, a thirteenth pin COMP, a fourteenth pin RT, a fifteenth pin SYNC and a sixteenth pin UVLO; the first pin VIN is connected to the positive electrode of the input end of the power supply, the eighth pin OUTA is connected to the control electrode of the first field effect transistor Q1, the ninth pin OUTB is connected to the second end of the twelfth capacitor C12, the tenth pin PGND and the eleventh pin AGND are grounded respectively, and the sixteenth pin UVLO is connected to the second end of the fifth resistor R5;

[0091] an eighth resistor R8, a fourteenth capacitor C14 and a fifteenth capacitor C15, a first end of the eighth resistor R8 and a first end of the fourteenth capacitor C14 are respectively connected to the first pin VIN, a second end of the eighth resistor R8 and a first end of the fifteenth capacitor C15 are respectively connected to the second pin RAMP, and a second end of the fourteenth capacitor C14 and a second end of the fifteenth capacitor C15 are respectively grounded;

[0092] A sixteenth capacitor C16, a first end of the sixteenth capacitor C16 is connected to the third pin CS1, and a second end of the sixteenth capacitor C16 is grounded;

[0093] a ninth resistor R9 and a seventeenth capacitor C17, wherein a first end of the ninth resistor R9 and a first end of the seventeenth capacitor C17 are respectively connected to the fourth pin CS2, and a second end of the ninth resistor R9 and a second end of the seventeenth capacitor C17 are respectively grounded;

[0094] a tenth resistor R10, wherein a first end of the tenth resistor R10 is connected to the fifth pin DEADTIME, and a second end of the tenth resistor R10 is grounded;

[0095] An eighteenth capacitor C18, a first end of the eighteenth capacitor C18 is connected to the sixth pin REF, and a second end of the eighteenth capacitor C18 is grounded;

[0096] a nineteenth capacitor C19 and a twenty-third capacitor C20, wherein a first end of the nineteenth capacitor C19 and a first end of the twenty-third capacitor C20 are respectively connected to the seventh pin VCC, and a second end of the nineteenth capacitor C19 and a second end of the twenty-third capacitor C20 are respectively grounded;

[0097] A twenty-first capacitor C21, a first end of the twenty-first capacitor C21 is connected to the twelfth pin SS, and a second end of the twenty-first capacitor C21 is grounded;

[0098] a twenty-second capacitor C22 and an eleventh resistor R11, a first end of the twenty-second capacitor C22 and a first end of the eleventh resistor R11 are respectively connected to the sixth pin REF, and a second end of the twenty-second capacitor C22 and a second end of the eleventh resistor R11 are respectively connected to the thirteenth pin COMP;

[0099] a twelfth resistor R12, a first end of the twelfth resistor R12 is connected to the fourteenth pin RT, and a second end of the twelfth resistor R12 is grounded;

[0100] a thirteenth resistor R13, a first end of the thirteenth resistor R13 is connected to the fifteenth pin SYNC, and a second end of the thirteenth resistor R13 is grounded;

[0101] a twenty-third capacitor C23, a fourteenth resistor R14 and a fifteenth resistor R15, wherein a first end of the twenty-third capacitor C23 is connected to a first end of the fourteenth resistor R14, a second end of the fourteenth resistor R14 is connected to a first end of the fifteenth resistor R15, and a second end of the fifteenth resistor R15 is connected to the fourth pin CS2; wherein a second end of the twenty-third capacitor C23 is grounded;

[0102] A ninth diode D9, a tenth diode D10 and a sixteenth resistor R16, wherein the anode of the ninth diode D9 and the anode of the tenth diode D10 are respectively connected to the first end of the sixteenth resistor R16, and the second end of the sixteenth resistor R16 is grounded; wherein the anode of the tenth diode D10 is connected to the non-same-name end of the secondary coil of the current transformer;

[0103] a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19 and a twentieth resistor R20, a first end of the seventeenth resistor R17, a first end of the eighteenth resistor R18 and a first end of the nineteenth resistor R19 are respectively connected to a first end of the twentieth resistor R20, a second end of the seventeenth resistor R17, a second end of the eighteenth resistor R18 and a second end of the nineteenth resistor R19 are respectively grounded, and a second end of the twentieth resistor R20 is connected to a third pin CS1; wherein a cathode of the ninth diode D9 and a cathode of the tenth diode D10 are respectively connected to a first end of the twentieth resistor R20;

[0104] In addition, the twenty-fourth capacitor C24, the twenty-first resistor R21, the eleventh diode D11, the twelfth diode D12 and the secondary winding of the energy storage coil, the anode of the eleventh diode D11, the anode of the twelfth diode D12 and the first end of the twenty-first resistor R21 are respectively connected to the first end of the secondary winding of the energy storage coil, the cathode of the eleventh diode D11 and the cathode of the twelfth diode D12 are respectively connected to the seventh pin VCC, the second end of the twenty-first resistor R21 is connected to the first end of the twenty-fourth capacitor C24, and the second end of the twenty-fourth capacitor C24 and the second end of the secondary winding of the energy storage coil are respectively grounded.

[0105] It can be understood that the voltage can be controlled by cooperating with the pulse width control circuit and the isolation sampling circuit, and the current can be controlled by cooperating with the pulse width control circuit and the overcurrent short circuit protection circuit. Therefore, the voltage and current can be controlled independently at the same time through the pulse width control circuit without affecting each other.

[0106] It should be noted that the anode of the ninth diode D9 and the anode of the tenth diode D10 are connected to the non-same-name ends of the secondary winding of the current transformer, so that the isolated sampled current signal can be coupled to the third pin CS1 of the chip U1 in the pulse width control circuit by the twentieth resistor R20 to realize current regulation control.

[0107] The model of chip U1 is LM5025. Among them, VIN represents the power input pin, RAMP represents the modulation ramp signal pin, CS1 represents the current input detection pin of cycle current limiting, CS2 represents the soft switching current sensing input pin, DEADTIME represents the output overlap and dead time control pin, REF represents the 5V reference voltage output pin, VCC represents the internal auxiliary power supply pin, OUTA represents the main switch pulse width modulation output driver output pin, OUTB represents the active clamp output drive pin, PGND represents the power ground pin, AGND represents the analog ground pin, SS represents the soft start control pin, COMP represents the pulse width modulation input pin, RT represents the oscillator timing resistor pin, SYNC represents the upper and lower synchronization input pins of the oscillator, and UVLO represents the line undervoltage shutdown pin.

[0108] It should be noted that the fifteenth pin SYNC does not need to be grounded to prevent interference.

[0109] In one embodiment, reference Figure 1 , the field effect rectifier circuit includes:

[0110] A third field effect transistor Q3 and a thirteenth diode D13, the source of the third field effect transistor Q3 and the cathode of the thirteenth diode D13 are respectively connected to the same-named ends of the secondary coil of the transformer, and the anode of the thirteenth diode D13 is connected to the drain of the third field effect transistor Q3;

[0111] The second triode N2 and the third triode N3, the emitter of the second triode N2 and the emitter of the third triode N3 are respectively connected to the control electrode of the third field effect transistor Q3, the collector of the second triode N2 is connected to the non-same-name end of the secondary coil of the transformer, and the collector of the third triode N3 is connected to the drain of the third field effect transistor Q3;

[0112] a twenty-second resistor R22, a twenty-fifth capacitor C25, a fourteenth diode D14 and a fifteenth diode D15, a first end of the twenty-second resistor R22, a first end of the twenty-fifth capacitor C25, an anode of the fourteenth diode D14 and an anode of the fifteenth diode D15 are respectively connected to the base of the second transistor N2, a second end of the twenty-second resistor R22, a second end of the twenty-fifth capacitor C25, a cathode of the fourteenth diode D14 and a cathode of the fifteenth diode D15 are respectively connected to non-same-name ends of the secondary coil of the transformer;

[0113] a second voltage zener diode DW2, an anode of the second voltage zener diode DW2 is connected to the collector of the third transistor N3, a cathode of the second voltage zener diode DW2 and a base of the third transistor N3 are respectively connected to the base of the second transistor N2, a cathode of the second voltage zener diode DW2 and a base of the third transistor N3 are respectively connected to the first end of the twenty-second resistor R22, a cathode of the second voltage zener diode DW2 and a base of the third transistor N3 are respectively connected to the first end of the twenty-fifth capacitor C25, a cathode of the second voltage zener diode DW2 and a base of the third transistor N3 are respectively connected to the anode of the fourteenth diode D14, and a cathode of the second voltage zener diode DW2 and a base of the third transistor N3 are respectively connected to the anode of the fifteenth diode D15;

[0114] A fourth field effect transistor Q4 and a sixteenth diode D16, wherein the source of the fourth field effect transistor Q4 and the cathode of the sixteenth diode D16 are respectively connected to non-same-name ends of the secondary winding of the transformer;

[0115] In addition, the seventeenth diode D17, the eighteenth diode D18, the twenty-third resistor R23, the twenty-sixth capacitor C26, the fourth triode N4, the fifth triode N5 and the third voltage stabilizing diode DW3, the cathode of the seventeenth diode D17, the cathode of the eighteenth diode D18, the first end of the twenty-third resistor R23, the first end of the twenty-sixth capacitor C26 and the collector of the fourth triode N4 are respectively connected to the same-name ends of the secondary winding of the transformer, the anode of the seventeenth diode D17, the anode of the eighteenth diode D18, the second end of the twenty-third resistor R23, the second end of the twenty-sixth capacitor C26, the base of the fourth triode N4 and the base of the fifth triode N5 are respectively connected to the cathode of the third voltage stabilizing diode DW3, and the emitter of the fourth triode N4 and the emitter of the fifth triode N5 are respectively connected to the control electrode of the fourth field effect transistor.

[0116] It can be understood that when the input voltage signal after power conversion is output to the field effect rectifier circuit through the secondary coil of the transformer, the input voltage signal after power conversion is rectified by the field effect rectifier circuit to obtain a rectified input voltage signal.

[0117] It should be noted that when rectifying the input voltage signal after power conversion, conventional diodes are not used for rectification, but field effect rectifier circuits are used for rectification, which can effectively reduce voltage fluctuations, improve power supply stability, and avoid introducing circuit harmonics.

[0118] In one embodiment, reference Figure 1 , the output filter circuit includes:

[0119] The second capacitor component, the primary winding package of the energy storage inductor, the twenty-fourth resistor R24, the twenty-seventh capacitor C27 and the nineteenth diode D19, the first end of the second capacitor component is connected to the first end of the primary winding package of the energy storage inductor, the first end of the second capacitor component is connected to the positive output terminal of the power supply, the second end of the second capacitor component is connected to the negative output terminal of the power supply, the anode of the nineteenth diode D19 is connected to the second end of the primary winding package of the energy storage inductor, the anode of the nineteenth diode D19 is connected to the same end of the secondary winding package of the transformer, the first end of the twenty-seventh capacitor C27 and the first end of the twenty-fourth resistor R24 ​​are respectively connected to the cathode of the nineteenth diode D19, and the second end of the twenty-seventh capacitor C27 is connected to the second end of the twenty-fourth resistor R24.

[0120] Understandably, reference Figure 1 , the second capacitor component includes a thirty-second capacitor C32, a thirty-third capacitor C33, a thirty-fourth capacitor C34, a thirty-fifth capacitor C35, a thirty-sixth capacitor C36, a thirty-seventh capacitor C37, a thirty-eighth capacitor C38, a thirty-ninth capacitor C39, a fortieth capacitor C40, a forty-first capacitor C41, a forty-second capacitor C42, a forty-third capacitor C43, a forty-fourth capacitor C44, a forty-fifth capacitor C45, a forty-sixth capacitor C46, ​​a forty-seventh capacitor C47, a forty-eighth capacitor C48, a forty-ninth capacitor C49, a fiftieth capacitor C50, a fifty-first capacitor C51, a fifty-second capacitor C52, a fifty-third capacitor C53, a fifty-fourth capacitor C54, a fifty-fifth capacitor C55, a fifty-sixth capacitor C56, a fifty-seventh capacitor C57 and a fifty-eighth capacitor C58 connected in parallel. Moreover, the 27 capacitors from the 32nd capacitor C32 to the 58th capacitor C58 are all small-capacity chip capacitors. These 27 small-capacity chip capacitors are used to filter the output voltage signal, so that the electromagnetic compatibility performance is strong and the filtering effect is good.

[0121] It should be noted that the energy storage coil L includes a primary coil and a secondary coil. The primary coil completes the inductance filtering and then cooperates with the second capacitor component in the output filter circuit to perform a filtering. In addition, the secondary coil can also generate the internal auxiliary power supply of the chip U1.

[0122] In one embodiment, reference Figure 1 , the isolated sampling circuit includes:

[0123] a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a twenty-ninth resistor R29, and a twentieth diode D20, wherein a first end of the twenty-fifth resistor R25, a first end of the twenty-sixth resistor R26, a first end of the twenty-seventh resistor R27, a first end of the twenty-eighth resistor R28, a first end of the twenty-ninth resistor R29, and a cathode of the twentieth diode D20 are respectively connected to the positive electrode of the output terminal of the power supply, and an anode of the twentieth diode D20 is connected to a second end of the twenty-ninth resistor R29;

[0124] a 30th resistor R30, a 31st resistor R31, a reference voltage controller U2, and a 28th capacitor C28, a first end of the 30th resistor R30, a first end of the 31st resistor R31, an anode of the reference voltage controller U2, and a first end of the 28th capacitor C28 are respectively connected to the negative electrode of the output end of the power supply, a second end of the 30th resistor R30, a second end of the 31st resistor R31, a second end of the 26th resistor R26, and a second end of the 27th resistor R27 are respectively connected to the reference end of the reference voltage controller U2, and a second end of the 28th capacitor C28 is connected to the second end of the 29th resistor R29;

[0125] a twenty-ninth capacitor C29 and a thirty-second resistor R32, wherein a first end of the twenty-ninth capacitor C29 is connected to a second end of the twenty-fifth resistor R25, and a second end of the twenty-ninth capacitor C29 and a first end of the thirty-second resistor R32 are respectively connected to a reference end of a reference voltage controller U2;

[0126] In addition, the 30th capacitor C30, the 33rd resistor R33, the 21st diode D21 and the optocoupler U3, the first end of the 30th capacitor C30, the first end of the 33rd resistor R33, the cathode of the reference voltage controller U2 and the anode of the 21st diode D21 are respectively connected to the cathode of the optocoupler U3, the second end of the 33rd resistor R33 is connected to the second end of the 28th resistor R28, the cathode of the 21st diode D21 is connected to the second end of the 29th resistor R29, and the second end of the 30th capacitor C30 is connected to the second end of the 32nd resistor R32; wherein, the anode of the optocoupler U3 is connected to the second end of the 28th resistor R28, the collector of the optocoupler U3 is connected to the 13th pin COMP in the pulse width control circuit, and the emitter of the optocoupler U3 is grounded.

[0127] It can be understood that after the output filter circuit outputs the rectified filter signal, the rectified filter signal is collected by the isolated sampling circuit to generate a control signal, which is output by the collector of the optocoupler U3 in the isolated sampling circuit to the thirteenth pin COMP in the chip U1 to control the output voltage signal. In addition, the present application uses a transformer T1 and an optocoupler U3 for isolation, so that the input and output ends of the DCDC conversion module are separated by space, and the application is safe and reliable.

[0128] In one embodiment, reference Figure 1 The anti-interference branch includes a thirty-first capacitor C31, an anode of the third voltage-stabilizing diode DW3, a collector of the fifth transistor N5, an anode of the sixteenth diode D16 and a drain of the fourth field-effect transistor Q4 are respectively connected to a first end of the thirty-first capacitor C31, and a second end of the thirty-first capacitor C31 is grounded.

[0129] It can be understood that the anti-interference branch can ensure that the input voltage signal after power conversion is not interfered by external factors when synchronous rectification is performed on the input voltage signal.

[0130] It should be noted that the DCDC conversion module of the present application consists of eight major parts: input filter circuit, power conversion circuit, undervoltage protection circuit, pulse width control circuit, synchronous rectification circuit, output filter circuit, anti-interference branch and isolation sampling circuit.

[0131] The DCDC conversion module of the present application adopts multi-parameter control and regulation, specifically, the voltage and current parameters are simultaneously regulated in the pulse width control circuit, independently and in parallel, and the control is completed in real time through the chip U1.

[0132] The input and output of the DCDC conversion module are completely isolated by transformer T1. At the same time, the pulse width control circuit is also completely isolated, and the output voltage signal uses an optocoupler U3 for photoelectric control isolation. The current signal uses current transformer T2 for magnetic isolation, which makes the DCDC conversion module have good isolation.

[0133] The input end and the first output end of the output filter circuit adopt electromagnetic compatibility technology, and use 27 small-capacity chip capacitors from the 32nd capacitor C32 to the 58th capacitor C58 for parallel filtering, which improves the anti-interference performance and electromagnetic compatibility performance. The synchronous rectification circuit is used for rectification, and the traditional diode is not used for rectification. Instead, the field effect tube synchronous rectification is used to avoid harmonic interference and stabilize the control performance.

[0134] Through these controls, the input and output ends of the DCDC conversion module are isolated, and the anti-interference and electromagnetic compatibility are strong, so that the performance of the DCDC conversion module is stable. Therefore, the present application can realize the isolation and conversion of the input voltage signal into the required output voltage signal.

[0135] It should be noted that the DCDC conversion module uses a variety of circuits, multiple methods, and multiple levels to achieve the conversion function, and in the process of implementation, other means are also taken to improve performance and enhance its reliability, especially in the input filter circuit part, using the first capacitor C1 to the tenth capacitor C10 ten small-capacity chip capacitors in parallel, the process uses an aluminum substrate, and the whole is potted and sealed. The product of the DCDC conversion module is divided into two layers in the internal structure: an aluminum substrate and a printed circuit board. The aluminum substrate and the printed circuit board are all made of chip components, with a volume of 58mm×37mm×12.7mm, which is a small volume. This application adopts the switching power supply control principle to realize DCDC DC conversion. For example: the DCDC conversion module is input with a 28V input voltage signal, the output voltage signal required for the isolated output is 28V, the power is 100W, and the efficiency can reach up to 91%, ensuring the reliability of the DCDC conversion module product. Therefore, the DCDC conversion module has the performance of small size, high power, high efficiency, high electromagnetic compatibility and strong anti-interference, and can be widely used in aviation, aerospace, petroleum, geological exploration, engineering control and other fields. In addition, the DCDC conversion module can be packaged in a metal casing, which can not only improve heat dissipation but also perform electromagnetic shielding to resist interference.

[0136] In the description of this specification, 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.

[0137] Those skilled in the art will readily come up with other embodiments of the present application after considering the specification and practicing the utility model disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application.

Claims

1. A DCDC conversion module, characterized in that: include: An input filter circuit, wherein the input end of the input filter circuit is connected to the positive electrode of the input end of the power supply, and the output end of the input filter circuit is connected to the negative electrode of the input end of the power supply; wherein the negative electrode of the input end of the power supply is grounded; A power conversion circuit, comprising a transformer primary coil, an overcurrent short-circuit protection circuit and a field effect control circuit, wherein the same-name end of the transformer primary coil is connected to the input end of the input filter circuit, the non-same-name end of the transformer primary coil is connected to the input end of the overcurrent short-circuit protection circuit, the first output end of the overcurrent short-circuit protection circuit is connected to the first input end of the field effect control circuit, and the output end of the field effect control circuit is grounded; An undervoltage protection circuit and a pulse width control circuit, wherein the input end of the undervoltage protection circuit is connected to the positive electrode of the input end of the power supply, the first output end of the undervoltage protection circuit is connected to the first input end of the pulse width control circuit, the second input end of the pulse width control circuit is connected to the positive electrode of the input end of the power supply, the first output end of the pulse width control circuit is connected to the second input end of the field effect control circuit, and the third input end of the pulse width control circuit is connected to the second output end of the overcurrent short circuit protection circuit; wherein the second output end of the undervoltage protection circuit and the second output end of the pulse width control circuit are grounded respectively; A synchronous rectification circuit, comprising a transformer secondary coil and a field effect rectification circuit, wherein the same-name end of the transformer secondary coil is connected to the input end of the field effect rectification circuit, and the non-same-name end of the transformer secondary coil is connected to the first output end of the field effect rectification circuit; An output filter circuit, wherein the input end of the output filter circuit is connected to the same-name end of the secondary coil of the transformer, the first output end of the output filter circuit is connected to the positive output end of the power supply, and the second output end of the output filter circuit is connected to the negative output end of the power supply; an anti-interference branch, wherein the input end of the anti-interference branch is connected to the second output end of the field effect rectifier circuit, and the output end of the anti-interference branch is grounded; And, an isolated sampling circuit, wherein the first input terminal of the isolated sampling circuit is connected to the positive input terminal of the power supply, the second input terminal of the isolated sampling circuit is connected to the negative input terminal of the power supply, the first output terminal of the isolated sampling circuit is connected to the fourth input terminal of the pulse width control circuit, and the second output terminal of the isolated sampling circuit is grounded.

2. The DCDC conversion module according to claim 1, characterized in that: The input filter circuit includes: a first capacitor component, a first end of the first capacitor component is connected to the positive input terminal of the power supply, and a second end of the first capacitor component is connected to the negative input terminal of the power supply.

3. The DCDC conversion module according to claim 2, characterized in that: The first capacitor component includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a tenth capacitor, wherein a first end of the first capacitor, a first end of the second capacitor, a first end of the third capacitor, a first end of the fourth capacitor, a first end of the fifth capacitor, a first end of the sixth capacitor, a first end of the seventh capacitor, a first end of the eighth capacitor, a first end of the ninth capacitor and a first end of the tenth capacitor are respectively connected to the positive electrode of the input terminal of the power supply, and a second end of the first capacitor, a second end of the second capacitor, a second end of the third capacitor, a second end of the fourth capacitor, a second end of the fifth capacitor, a second end of the sixth capacitor, a second end of the seventh capacitor, a second end of the eighth capacitor, a second end of the ninth capacitor and a second end of the tenth capacitor are respectively connected to the negative electrode of the input terminal of the power supply.

4. The DCDC conversion module according to claim 3, characterized in that: The over-current short-circuit protection circuit comprises: a primary coil of a current transformer and a secondary coil of a current transformer, the same-name end of the primary coil of the current transformer is connected to the non-same-name end of the primary coil of the transformer, and the same-name end of the secondary coil of the current transformer is grounded; The field effect control circuit comprises: a first field effect tube, an eleventh capacitor and a first diode, wherein the source of the first field effect tube, the first end of the eleventh capacitor and the cathode of the first diode are respectively connected to the non-same-name ends of the primary coil of the current transformer; wherein the drain of the first field effect tube and the anode of the first diode are respectively grounded; a second field effect transistor and a second diode, wherein the source of the second field effect transistor and the anode of the second diode are respectively connected to the second end of the eleventh capacitor, and the drain of the second field effect transistor and the cathode of the second diode are respectively grounded; And, a first resistor, a second resistor, a third diode, a fourth diode and a twelfth capacitor, the first end of the first resistor is connected to the control electrode of the first field effect transistor, the first end of the second resistor, the anode of the third diode, the anode of the fourth diode and the first end of the twelfth capacitor are respectively connected to the control electrode of the second field effect transistor; wherein the second end of the first resistor, the second end of the second resistor, the cathode of the third diode and the cathode of the fourth diode are respectively grounded.

5. The DCDC conversion module according to claim 4, characterized in that: The undervoltage protection circuit comprises: a third resistor and a first voltage stabilizing diode, wherein a first end of the third resistor and a cathode of the first voltage stabilizing diode are respectively connected to a positive electrode of an input end of the power supply; a fifth diode, a sixth diode, a first triode, a fourth resistor, a fifth resistor and a thirteenth capacitor, wherein the anode of the fifth diode, the anode of the sixth diode, the first end of the fourth resistor, the first end of the fifth resistor, the first end of the thirteenth capacitor and the second end of the third resistor are respectively connected to the collector of the first triode; wherein the emitter of the first triode, the second end of the fourth resistor and the second end of the thirteenth capacitor are respectively grounded, and the cathode of the fifth diode and the cathode of the sixth diode are respectively connected to the grounding prohibition terminal; And, a seventh diode, an eighth diode, a sixth resistor and a seventh resistor, the anode of the seventh diode and the anode of the eighth diode are respectively connected to the anode of the first voltage zener diode, the cathode of the seventh diode and the cathode of the eighth diode are respectively connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the base of the first transistor, and the first end of the seventh resistor is connected to the first end of the sixth resistor; wherein the second end of the seventh resistor is grounded.

6. The DCDC conversion module according to claim 5, characterized in that: The pulse width control circuit comprises: A chip, comprising a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin, an eighth pin, a ninth pin, a tenth pin, an eleventh pin, a twelfth pin, a thirteenth pin, a fourteenth pin, a fifteenth pin and a sixteenth pin; the first pin is connected to the positive electrode of the input end of the power supply, the eighth pin is connected to the control electrode of the first field effect transistor, the ninth pin is connected to the second end of the twelfth capacitor, the tenth pin and the eleventh pin are grounded respectively, and the sixteenth pin is connected to the second end of the fifth resistor; an eighth resistor, a fourteenth capacitor and a fifteenth capacitor, wherein a first end of the eighth resistor and a first end of the fourteenth capacitor are respectively connected to the first pin, a second end of the eighth resistor and a first end of the fifteenth capacitor are respectively connected to the second pin, and a second end of the fourteenth capacitor and a second end of the fifteenth capacitor are respectively grounded; a sixteenth capacitor, a first end of the sixteenth capacitor being connected to the third pin, and a second end of the sixteenth capacitor being grounded; a ninth resistor and a seventeenth capacitor, wherein a first end of the ninth resistor and a first end of the seventeenth capacitor are respectively connected to the fourth pin, and a second end of the ninth resistor and a second end of the seventeenth capacitor are respectively grounded; a tenth resistor, a first end of the tenth resistor being connected to the fifth pin, and a second end of the tenth resistor being grounded; an eighteenth capacitor, a first end of the eighteenth capacitor being connected to the sixth pin, and a second end of the eighteenth capacitor being grounded; a nineteenth capacitor and a twenty-third capacitor, wherein a first end of the nineteenth capacitor and a first end of the twenty-third capacitor are respectively connected to the seventh pin, and a second end of the nineteenth capacitor and a second end of the twenty-third capacitor are respectively grounded; A twenty-first capacitor, a first end of the twenty-first capacitor is connected to the twelfth pin, and a second end of the twenty-first capacitor is grounded; a twenty-second capacitor and an eleventh resistor, wherein a first end of the twenty-second capacitor and a first end of the eleventh resistor are respectively connected to the sixth pin, and a second end of the twenty-second capacitor and a second end of the eleventh resistor are respectively connected to the thirteenth pin; a twelfth resistor, a first end of the twelfth resistor being connected to the fourteenth pin, and a second end of the twelfth resistor being grounded; a thirteenth resistor, a first end of the thirteenth resistor being connected to the fifteenth pin, and a second end of the thirteenth resistor being grounded; a twenty-third capacitor, a fourteenth resistor and a fifteenth resistor, wherein a first end of the twenty-third capacitor is connected to a first end of the fourteenth resistor, a second end of the fourteenth resistor is connected to a first end of the fifteenth resistor, and a second end of the fifteenth resistor is connected to the fourth pin; wherein a second end of the twenty-third capacitor is grounded; A ninth diode, a tenth diode and a sixteenth resistor, wherein the anode of the ninth diode and the anode of the tenth diode are respectively connected to the first end of the sixteenth resistor, and the second end of the sixteenth resistor is grounded; wherein the anode of the tenth diode is connected to the non-same-name end of the secondary coil of the current transformer; a seventeenth resistor, an eighteenth resistor, a nineteenth resistor and a twentieth resistor, wherein the first end of the seventeenth resistor, the first end of the eighteenth resistor and the first end of the nineteenth resistor are respectively connected to the first end of the twentieth resistor, the second end of the seventeenth resistor, the second end of the eighteenth resistor and the second end of the nineteenth resistor are respectively grounded, and the second end of the twentieth resistor is connected to the third pin; wherein the cathode of the ninth diode and the cathode of the tenth diode are respectively connected to the first end of the twentieth resistor; In addition, the twenty-fourth capacitor, the twenty-first resistor, the eleventh diode, the twelfth diode and the secondary winding of the energy storage coil, the anode of the eleventh diode, the anode of the twelfth diode and the first end of the twenty-first resistor are respectively connected to the first end of the secondary winding of the energy storage coil, the cathode of the eleventh diode and the cathode of the twelfth diode are respectively connected to the seventh pin, the second end of the twenty-first resistor is connected to the first end of the twenty-fourth capacitor, and the second end of the twenty-fourth capacitor and the second end of the secondary winding of the energy storage coil are respectively grounded.

7. The DCDC conversion module according to claim 6, characterized in that: The field effect rectifier circuit comprises: a third field effect tube and a thirteenth diode, wherein the source of the third field effect tube and the cathode of the thirteenth diode are respectively connected to the same-named ends of the secondary coil of the transformer, and the anode of the thirteenth diode is connected to the drain of the third field effect tube; A second triode and a third triode, wherein the emitter of the second triode and the emitter of the third triode are respectively connected to the control electrode of the third field effect tube, the collector of the second triode is connected to the non-same-name end of the secondary coil of the transformer, and the collector of the third triode is connected to the drain of the third field effect tube; a twenty-second resistor, a twenty-fifth capacitor, a fourteenth diode and a fifteenth diode, wherein the first end of the twenty-second resistor, the first end of the twenty-fifth capacitor, the anode of the fourteenth diode and the anode of the fifteenth diode are respectively connected to the base of the second transistor, and the second end of the twenty-second resistor, the second end of the twenty-fifth capacitor, the cathode of the fourteenth diode and the cathode of the fifteenth diode are respectively connected to the non-same-name ends of the secondary coil of the transformer; a second voltage-stabilizing diode, wherein the anode of the second voltage-stabilizing diode is connected to the collector of the third transistor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the base of the second transistor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the first end of the twenty-second resistor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the first end of the twenty-fifth capacitor, the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the anode of the fourteenth diode, and the cathode of the second voltage-stabilizing diode and the base of the third transistor are respectively connected to the anode of the fifteenth diode; A fourth field effect transistor and a sixteenth diode, wherein the source of the fourth field effect transistor and the cathode of the sixteenth diode are respectively connected to non-same-name ends of the secondary winding of the transformer; In addition, the seventeenth diode, the eighteenth diode, the twenty-third resistor, the twenty-sixth capacitor, the fourth transistor, the fifth transistor and the third voltage-stabilizing diode, the cathode of the seventeenth diode, the cathode of the eighteenth diode, the first end of the twenty-third resistor, the first end of the twenty-sixth capacitor and the collector of the fourth transistor are respectively connected to the same-name ends of the secondary winding of the transformer, the anode of the seventeenth diode, the anode of the eighteenth diode, the second end of the twenty-third resistor, the second end of the twenty-sixth capacitor, the base of the fourth transistor and the base of the fifth transistor are respectively connected to the cathode of the third voltage-stabilizing diode, and the emitter of the fourth transistor and the emitter of the fifth transistor are respectively connected to the control electrode of the fourth field-effect transistor.

8. The DCDC conversion module according to claim 7, characterized in that: The output filter circuit comprises: A second capacitor component, a primary winding package of an energy storage inductor, a twenty-fourth resistor, a twenty-seventh capacitor and a nineteenth diode, wherein the first end of the second capacitor component is connected to the first end of the primary winding package of the energy storage inductor, the first end of the second capacitor component is connected to the positive output terminal of the power supply, the second end of the second capacitor component is connected to the negative output terminal of the power supply, the anode of the nineteenth diode is connected to the second end of the primary winding package of the energy storage inductor, the anode of the nineteenth diode is connected to the same-name end of the secondary winding package of the transformer, the first end of the twenty-seventh capacitor and the first end of the twenty-fourth resistor are respectively connected to the cathode of the nineteenth diode, and the second end of the twenty-seventh capacitor is connected to the second end of the twenty-fourth resistor.

9. The DCDC conversion module according to claim 8, characterized in that: The isolation sampling circuit comprises: a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, and a twenty-tenth diode, wherein a first end of the twenty-fifth resistor, a first end of the twenty-sixth resistor, a first end of the twenty-seventh resistor, a first end of the twenty-eighth resistor, a first end of the twenty-ninth resistor, and a cathode of the twenty-tenth diode are respectively connected to the positive electrode of the output terminal of the power supply, and an anode of the 20th diode is connected to the second end of the 29th resistor; a 30th resistor, a 31st resistor, a reference voltage controller, and a 28th capacitor, wherein a first end of the 30th resistor, a first end of the 31st resistor, an anode of the reference voltage controller, and a first end of the 28th capacitor are respectively connected to the negative electrode of the output terminal of the power supply, a second end of the 30th resistor, a second end of the 31st resistor, a second end of the 26th resistor, and a second end of the 27th resistor are respectively connected to the reference terminal of the reference voltage controller, and a second end of the 28th capacitor is connected to the second end of the 29th resistor; a twenty-ninth capacitor and a thirty-second resistor, wherein a first end of the twenty-ninth capacitor is connected to a second end of the twenty-fifth resistor, and a second end of the twenty-ninth capacitor and a first end of the thirty-second resistor are respectively connected to a reference end of the reference voltage controller; And, a 30th capacitor, a 33rd resistor, a 21st diode and an optocoupler, the first end of the 30th capacitor, the first end of the 33rd resistor, the cathode of the reference voltage controller and the anode of the 21st diode are respectively connected to the cathode of the optocoupler, the second end of the 33rd resistor is connected to the second end of the 28th resistor, the cathode of the 21st diode is connected to the second end of the 29th resistor, and the second end of the 30th capacitor is connected to the second end of the 32nd resistor; wherein the anode of the optocoupler is connected to the second end of the 28th resistor, the collector of the optocoupler is connected to the 13th pin in the pulse width control circuit, and the emitter of the optocoupler is grounded.

10. The DCDC conversion module according to claim 9, characterized in that: The anti-interference branch includes a thirty-first capacitor, the anode of the third voltage-stabilizing diode, the collector of the fifth transistor, the anode of the sixteenth diode and the drain of the fourth field-effect transistor are respectively connected to the first end of the thirty-first capacitor, and the second end of the thirty-first capacitor is grounded.

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