A magnetic isolation dc-dc converter with anti-radiation characteristics

Abstract

This invention discloses a DC-DC converter with magnetic isolation and radiation resistance characteristics, belonging to the field of circuit technology. It includes: a secondary-primary side control and signal magnetic isolation transmission circuit, an RCC self-excited push-pull magnetic isolation power supply circuit, a current sampling circuit, and a secondary-side main control chip circuit. The secondary-primary side control and signal magnetic isolation transmission circuit has a primary-side isolation drive control circuit and a secondary-side isolation drive control circuit. The RCC self-excited push-pull magnetic isolation power supply circuit is responsible for power supply. The primary-side isolation drive control circuit is connected to the primary side of the magnetic isolation power supply transformer, and the secondary-side isolation drive control circuit is connected to the secondary side of the magnetic isolation power supply transformer. The secondary-primary side control and signal magnetic isolation transmission circuit is connected to the secondary-side main control chip circuit, and the secondary-side main control chip circuit is connected to the current sampling circuit. This invention has a simple circuit structure, which helps to reduce costs and increase power density; it is suitable for various magnetically isolated switching power supplies.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and specifically to a DC-DC converter with magnetic isolation and radiation resistance characteristics. Background Technology

[0002] Currently, most power supply designs for switching power supplies with magnetic isolation and radiation resistance utilize primary-side control based on chips such as HS1843 and UEC1843. This primary-side control requires magnetic isolation feedback, which involves numerous magnetic components and suffers from long transmission delays and distortion. Furthermore, the magnetic properties of these components are highly sensitive to temperature, leading to poor loop response stability and untimely dynamic response. To address these issues, current primary-side control chips with radiation resistance, such as those based on HS1843 and UEC1843, have limited integrated functionality. Overvoltage / overtemperature protection and other functions require external implementation, consuming additional space and components.

[0003] Therefore, it is necessary to provide a power supply design that combines magnetic isolation and radiation resistance with overvoltage / overtemperature protection. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a magnetically isolated and radiation-resistant DC-DC converter, thereby solving the problems of limited functionality of the primary-side control chip in the prior art, and the need for external devices to build overcurrent / overvoltage / overtemperature protection functions, which consumes additional space and components.

[0005] According to a first aspect, embodiments of the present invention provide a magnetically isolated and radiation-resistant DC-DC converter, comprising:

[0006] Secondary-primary side control and signal magnetic isolation transmission circuit, RCC self-excited push-pull magnetic isolation power supply circuit, current sampling circuit and secondary-side main control chip circuit;

[0007] The secondary-primary side control and signal magnetic isolation transmission circuit has a primary side isolation drive control circuit and a secondary side isolation drive control circuit. The RCC self-excited push-pull magnetic isolation power supply circuit supplies power to the primary side isolation drive control circuit, the secondary side isolation drive control circuit, and the secondary side main control chip circuit in the secondary-primary side control and signal magnetic isolation transmission circuit. The primary side isolation drive control circuit is connected to the primary side of the magnetic isolation power supply transformer, and the secondary side isolation drive control circuit is connected to the secondary side of the magnetic isolation power supply transformer.

[0008] The secondary-primary side control and signal magnetic isolation transmission circuit is connected to the secondary-side main control chip circuit, and the secondary-side main control chip circuit is connected to the current sampling circuit.

[0009] In conjunction with the first aspect, in the first embodiment of the first aspect, the secondary side main control chip adopts the RSS3802QRH model chip.

[0010] In conjunction with the first aspect, in the second embodiment of the first aspect, the primary-side isolation drive control chip adopts the RS1010BCD model chip.

[0011] In conjunction with the first aspect, in the third embodiment of the first aspect, the secondary-side isolation drive control chip adopts the RS1010ACD model chip.

[0012] In conjunction with the first aspect, in the fourth embodiment of the first aspect, the RCC self-excited push-pull magnetically isolated power supply circuit includes:

[0013] The primary winding of the magnetically isolated power supply transformer has a first winding X3-X4X5-X6 and a second winding X7-X8X9-X10.

[0014] In the first winding X3-X4X5-X6, the X3 winding coil is at the same end to the opposite end relative to the X4X5 winding coil, the X4X5 winding coil is at the same end to the opposite end relative to the X6 winding coil, and the X4X5 winding coil is the center tap of the X3-X4 winding coil and the X5-X6 winding coil.

[0015] In the second winding X7-X8X9-X10, the X7 winding coil is connected with the X8X9 winding coil at the same end to the opposite end, the X8X9 winding coil is connected with the X10 winding coil at the same end to the opposite end, and the X8X9 winding coil is the center tap of the X7-X8 winding coil and the X8-X9 winding coil.

[0016] The secondary windings of the magnetically isolated power supply transformer are Y5-Y6Y7-Y8;

[0017] In the secondary winding Y5-Y6Y7-Y8, the Y5 winding coil is connected with the Y6Y7 winding coil at the same end to the opposite end, and the Y6Y7 winding coil is connected with the Y8 winding coil at the same end to the opposite end. The Y6Y7 winding coil is the center tap of the Y5-Y6 winding coil and the Y6-Y7 winding coil.

[0018] In conjunction with the fourth embodiment of the first aspect, in the fifth embodiment of the first aspect, the RCC self-excited push-pull magnetically isolated power supply circuit further includes:

[0019] The fifth PNP transistor Q5, the sixth PNP transistor Q6, the tenth resistor R10, the eleventh resistor R11, the eighth resistor R8, the eleventh capacitor C11, the fourteenth capacitor C14, the seventh diode D7, and the eighth diode D8.

[0020] The collector (C) of the fifth PNP transistor Q5 is connected to the X3 winding of the first winding X3-X4X5-X6, the emitter (E) is connected to the primary ground (PGND), the base (B) is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to the X10 winding of the second winding X7-X8X9-X10.

[0021] The collector (C) of the sixth PNP transistor Q6 is connected to the X6 winding of the first winding X3-X4X5-X6, the emitter (E) is connected to the PGND terminal, the base (B) is connected to one end of the tenth resistor R10, and the other end of the tenth resistor R10 is connected to the X7 winding of the second winding X7-X8X9-X10.

[0022] The eighth resistor R8 is connected to one end of the eleventh capacitor C11, and the connected end is connected to the X8X9 end of the primary winding X7-X8X9-X10 of the magnetic isolation power supply transformer. The other end of the eleventh capacitor C11 is connected to the primary ground PGND end, and the other end of the eighth resistor R8 is connected to the X4X5 winding end of the first winding X3-X4X5-X6. At the same time, the X4X5 winding end is connected to the primary power supply VCC end.

[0023] The anode of the seventh diode D7 is connected to the Y5 winding of the secondary winding Y5-Y6Y7-Y8 of the magnetically isolated power supply transformer, and the cathode is connected to the eighth diode D8. The anode of the eighth diode D8 is connected to the Y8 winding of the secondary winding Y5-Y6Y7-Y8 of the magnetically isolated power supply transformer, and the cathode is connected to the cathode of the seventh diode D7. The Y6Y7 winding of the second winding Y5-Y6Y7-Y8 is connected to the secondary ground GND.

[0024] In conjunction with the fifth embodiment of the first aspect, in the sixth embodiment of the first aspect, the primary-side power supply VCC of the RCC self-excited push-pull magnetically isolated power supply circuit charges the X8X9 winding coil of the second winding X7-X8X9-X10 through the eighth resistor R8 and the eleventh capacitor C11. The X8X9 winding coil charges the base of the fifth transistor Q5 and the sixth transistor Q6 through the eleventh resistor R11 and the tenth resistor R10. Due to the inconsistency of the base injection current of Q5 and Q6, one of Q5 and Q6 turns on before the other. If Q5 turns on first, that is, the high level is first at X10. Since the winding polarity of the primary winding of the magnetically isolated power supply transformer X10 and X3 are opposite... At terminal X3, the voltage level is low, meaning transistor Q5 is conducting. Meanwhile, for transistor Q6, since X7 is low and X6 is high, Q6 is not conducting. This is equivalent to the induced electromotive force generated when Q5 is conducting suppressing the conduction of Q6. When the rate of change of the current in Q5 is zero, according to Lenz's law, the electromotive force will reverse, and Q6 will conduct, thus suppressing Q5's conduction. This process repeats, achieving alternating conduction of the two transistors and realizing self-oscillation. Essentially, the primary side of the magnetically isolated power supply transformer provides an oscillating square wave signal, inducing two complementary square waves on the secondary side. These, through D7 and D8, synthesize a stable secondary DC power supply level SVCC, supplying power to the secondary main control chip circuit.

[0025] In conjunction with the first embodiment of the first aspect, in the seventh embodiment of the first aspect, the secondary side main control chip adopts the RSS3802QRH model chip, which integrates the disable function, overvoltage protection function, and current sampling and detection function.

[0026] The secondary-side main control chip circuit includes:

[0027] The forty-fifth resistor R45, the forty-fourth resistor R44; the fiftieth resistor R50, the fifty-first resistor R51, and the twenty-second resistor R22;

[0028] The forty-fifth resistor R45 is connected to the secondary power supply SVCC level, and its other end is connected to the forty-fourth resistor R44. The other end of R44 is connected to the secondary side GND. The common connection terminal of R45 and R44 is connected to the disable pin EN of the RSS3802QRH chip. The disable / enable function of the RSS3802QRH chip is realized by setting the resistance values ​​of R45 and R44. The fiftieth resistor R50 is connected at one end to the output voltage VOUT terminal and at the other end to the fifty-first resistor R51. The other end is connected to the secondary ground GND terminal. The common connection terminal of R50 and R51 is connected to the overvoltage pin OVP terminal of the RSS3802QRH chip. The overvoltage protection function of the RSS3802QRH chip is realized by setting the resistance values ​​of R50 and R51. One end of the 22nd resistor R22 is connected to the current sampling circuit terminal and the other end is connected to the CS terminal of the RSS3802QRH chip. The signal transmitted from CS is sampled and detected by the built-in circuit of RSS3802QRH.

[0029] In conjunction with the first aspect, in the eighth embodiment of the first aspect, the current sampling circuit includes:

[0030] The sixth diode D6, the twelfth resistor R12, the thirteenth resistor R13, the fifteenth resistor R15, and the transformer coil winding CT1;

[0031] The fifteenth resistor R15 and the sixth diode D6 convert the primary circuit current collected by the transformer coil winding into a voltage signal through the twelfth resistor R12 and the thirteenth resistor R13, and transmit it to the current detection CS terminal of the RSS3802QRH chip. The RSS3802QRH chip controls the energy transfer according to the load power of the magnetically isolated and radiation-resistant DC-DC converter. When the DC-DC converter power increases, the voltage signal sampled by the current detection CS increases, and the RSS3802QRH chip adjusts the duty cycle of the drive signal accordingly to increase energy transfer; conversely, it decreases the duty cycle to reduce energy transfer, thereby maintaining the stability of the DC-DC converter output voltage.

[0032] In conjunction with the second and third embodiments of the first aspect, in the eighth embodiment of the first aspect, the secondary-primary side control and signal magnetic isolation transmission circuit includes an RS1010BCD chip and an RS1010ACD chip.

[0033] The RS1010BCD and RS1010ACD chips have built-in magnetic isolation drive signal transmission functions. The RS1010BCD chip can transmit the drive signal of the secondary-side main control RSS3802QRH chip to the RS1010ACD chip, thereby controlling the operation of the power device. The RS1010BCD and RS1010ACD chips have built-in magnetic isolation drive signal transmission functions.

[0034] This invention provides a magnetically isolated and radiation-resistant DC-DC converter. Through an RCC self-excited push-pull magnetically isolated power supply circuit, it powers the secondary and primary-side isolated drive control circuits and the secondary-side main control chip circuit, thus providing a magnetically isolated auxiliary power supply. The secondary-primary side control and signal magnetically isolated transmission circuits enable magnetically isolated transmission control of the drive signal. The secondary-side main control chip circuit enables overvoltage and current sampling detection functions. Radiation resistance is achieved through the selection of a radiation-resistant chip and a magnetically isolated power supply. The switching power supply exhibits fast response speed under various operating conditions, smooth waveform recovery, minimal ringing, and stable loop state. It eliminates the need for an additional radiation-resistant auxiliary power chip and a separate auxiliary power supply, resulting in a simple circuit structure that reduces costs and increases power density. It is suitable for various magnetically isolated switching power supplies. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] in:

[0037] Figure 1 This invention provides a schematic diagram of one of the structures of a DC-DC converter with magnetic isolation and radiation resistance characteristics.

[0038] Figure 1.1 It shows Figure 1 One of the enlarged images;

[0039] Figure 1.2 It shows Figure 1 Partial enlarged image 2;

[0040] Figure 1.3 It shows Figure 1 Partial enlarged image three;

[0041] Figure 2 This is the second schematic diagram of the structure of the magnetically isolated and radiation-resistant DC-DC converter provided by the present invention;

[0042] Figure 2.1 It shows Figure 2 One of the enlarged images;

[0043] Figure 2.2 It shows Figure 2 Part 2 of the enlarged images. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Currently, most power supply designs for switching power supplies with magnetic isolation and radiation resistance utilize primary-side control based on chips such as HS1843 and UEC1843. This primary-side control requires magnetic isolation feedback, which involves numerous magnetic components and suffers from long transmission delays and distortion. Furthermore, the magnetic properties of these components are highly sensitive to temperature, leading to poor loop response stability and untimely dynamic response. To address these issues, current primary-side control chips with radiation resistance, such as those based on HS1843 and UEC1843, have limited integrated functionality. Overvoltage / overtemperature protection and other functions require external implementation, consuming additional space and components.

[0046] Therefore, it is necessary to provide a power supply design that combines magnetic isolation and radiation resistance with overvoltage / overtemperature protection.

[0047] To address the aforementioned issues, this specification provides a magnetically isolated DC-DC converter with radiation resistance. For example... Figure 1 and Figure 2 As shown, the converter may include:

[0048] Secondary-primary side control and signal magnetic isolation transmission circuit, RCC self-excited push-pull magnetic isolation power supply circuit, current sampling circuit and secondary-side main control chip circuit;

[0049] The secondary-primary side control and signal magnetic isolation transmission circuit has a primary side isolation drive control circuit and a secondary side isolation drive control circuit. The RCC self-excited push-pull magnetic isolation power supply circuit supplies power to the primary side isolation drive control circuit, the secondary side isolation drive control circuit, and the secondary side main control chip circuit in the secondary-primary side control and signal magnetic isolation transmission circuit. The primary side isolation drive control circuit is connected to the primary side of the magnetic isolation power supply transformer, and the secondary side isolation drive control circuit is connected to the secondary side of the magnetic isolation power supply transformer.

[0050] The secondary-primary side control and signal magnetic isolation transmission circuit is connected to the secondary-side main control chip circuit, and the secondary-side main control chip circuit is connected to the current sampling circuit.

[0051] Preferably, in this embodiment, the secondary-side main control chip is an RSS3802QRH chip. The primary-side isolation drive control chip is an RS1010BCD chip, and the secondary-side isolation drive control chip is an RS1010ACD chip.

[0052] The RCC self-excited push-pull magnetically isolated power supply circuit includes:

[0053] The primary winding of the magnetically isolated power supply transformer has a convoluted primary winding structure: first winding X3-X4X5-X6 and second winding X7-X8X9-X10.

[0054] The primary winding of the magnetically isolated power supply transformer consists of four windings forming two windings. In the first winding (X3-X4X5-X6), the X3 winding is positioned with the same end facing the opposite end relative to the X4X5 winding, and the X4X5 winding is positioned with the same end facing the opposite end relative to the X6 winding. The X4X5 winding is the center tap of the X3-X4 and X5-X6 windings. In the second winding (X7-X8X9-X10), the X7 winding is positioned with the same end facing the opposite end relative to the X8X9 winding, and the X8X9 winding is positioned with the same end facing the opposite end relative to the X10 winding. The X8X9 winding is the center tap of the X7-X8 and X8-X9 windings.

[0055] The secondary windings of the magnetically isolated power supply transformer are Y5-Y6Y7-Y8;

[0056] The secondary winding of the magnetically isolated power supply transformer consists of two windings forming a winding Y5-Y6Y7-Y8. In the secondary winding Y5-Y6Y7-Y8, the Y5 winding is connected from the Y6-Y7 winding with the same end to the opposite end, and the Y6-Y7 winding is connected from the Y8 winding with the same end to the opposite end. The Y6-Y7 winding is the center tap of both the Y5-Y6 and Y6-Y7 windings.

[0057] The RCC self-excited push-pull magnetically isolated power supply circuit also includes:

[0058] The fifth PNP transistor Q5, the sixth PNP transistor Q6, the tenth resistor R10, the eleventh resistor R11, the eighth resistor R8, the eleventh capacitor C11, the fourteenth capacitor C14, the seventh diode D7, and the eighth diode D8.

[0059] The collector (C) of the fifth PNP transistor Q5 is connected to the X3 winding of the first winding X3-X4X5-X6, the emitter (E) is connected to the primary ground PGND, the base (B) is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to the X10 winding of the second winding X7-X8X9-X10.

[0060] The collector (C) of the sixth PNP transistor Q6 is connected to the X6 winding of the first winding X3-X4X5-X6, the emitter (E) is connected to the PGND terminal, the base (B) is connected to one end of the tenth resistor R10, and the other end of the tenth resistor R10 is connected to the X7 winding of the second winding X7-X8X9-X10.

[0061] The eighth resistor R8 is connected to one end of the eleventh capacitor C11, and the connected end is connected to the X8X9 end of the primary winding X7-X8X9-X10 of the magnetic isolation power supply transformer. The other end of the eleventh capacitor C11 is connected to the primary ground PGND end. The other end of the eighth resistor R8 is connected to the X4X5 winding end of the first winding X3-X4X5-X6, and the X4X5 winding end is connected to the primary power supply VCC end.

[0062] The anode of the seventh diode D7 is connected to the Y5 winding of the secondary winding Y5-Y6Y7-Y8 of the magnetically isolated power supply transformer, and the cathode is connected to the eighth diode D8. The anode of the eighth diode D8 is connected to the Y8 winding of the secondary winding Y5-Y6Y7-Y8 of the magnetically isolated power supply transformer, and the cathode is connected to the cathode of the seventh diode D7. The Y6Y7 of the second winding Y5-Y6Y7-Y8 is connected to the secondary ground GND.

[0063] In the RCC self-excited push-pull magnetically isolated power supply circuit, the primary-side power supply VCC charges the X8X9 winding of the second winding X7-X8X9-X10 through the eighth resistor R8 and the eleventh capacitor C11. The X8X9 winding charges the base (B) of the fifth transistor Q5 and the sixth transistor Q6 through the eleventh resistor R11 and the tenth resistor R10. Due to the inconsistency of the base current injected into Q5 and Q6, one of Q5 and Q6 turns on before the other. If Q5 turns on first, that is, X10 is high-level first. Since the winding polarity of the primary winding of the magnetically isolated power supply transformer X10 and X3 are opposite, X3 is low-level, meaning that transistor Q5 turns on first. The circuit is open. However, for transistor Q6 at this time, since X7 is at a low level and X6 is at a high level, transistor Q6 is not conducting. This is equivalent to the induced electromotive force generated when transistor Q5 is conducting suppressing the conduction of Q6. When the rate of change of the conduction current of Q5 is 0, according to Lenz's law, the electromotive force will reverse, and Q6 will conduct, thus suppressing the conduction of Q5. This process repeats, achieving the alternating conduction of the two transistors and realizing the purpose of self-excited oscillation. This is equivalent to the primary side of the magnetic isolation power supply transformer providing an oscillating square wave signal, inducing two complementary square waves on the secondary side. Through D7 and D8, a stable secondary DC power supply level SVCC is synthesized to power the secondary main control chip circuit.

[0064] The secondary-side main control chip uses the RSS3802QRH model, which integrates disable function, overvoltage protection function, and current sampling and detection function. Correspondingly, the secondary-side main control chip circuit includes:

[0065] The forty-fifth resistor R45, the forty-fourth resistor R44; the fiftieth resistor R50, the fifty-first resistor R51, and the twenty-second resistor R22;

[0066] The forty-fifth resistor, R45, is connected to the secondary power supply at level SVCC, and the other end is connected to the forty-fourth resistor, R44. The other end of R44 is connected to the secondary side GND. The common connection of R45 and R44 is connected to the disable pin EN of the RSS3802QRH chip. By setting the resistance values ​​of R45 and R44, the disable / enable function of the RSS3802QRH chip is achieved. The fiftieth resistor, R50, has one end connected to the output voltage VOUT and the other end connected to the fifty-first resistor, R51. The other end of R51 is connected to the secondary side ground GND. The common connection of R50 and R51 is connected to the overvoltage pin OVP of the RSS3802QRH chip. By setting the resistance values ​​of R50 and R51, the overvoltage protection function of the RSS3802QRH chip is achieved. The twenty-second resistor, R22, has one end connected to the current sampling circuit and the other end connected to the CS pin of the RSS3802QRH chip. The RSS3802QRH's built-in circuit samples and detects the signal transmitted from CS.

[0067] The current sampling circuit includes:

[0068] The sixth diode D6, the twelfth resistor R12, the thirteenth resistor R13, the fifteenth resistor R15, and the transformer coil winding CT1;

[0069] The fifteenth resistor R15 and the sixth diode D6 convert the primary circuit current collected from the transformer coil winding into a voltage signal via the twelfth resistor R12 and the thirteenth resistor R13, which is then transmitted to the current detection CS terminal of the RSS3802QRH chip. The RSS3802QRH chip controls energy transfer based on the load power of the magnetically isolated and radiation-resistant DC-DC converter. When the DC-DC converter power increases, the voltage signal sampled by the current detection CS increases, and the RSS3802QRH chip adjusts the duty cycle of the drive signal accordingly to increase energy transfer; conversely, it decreases the duty cycle to reduce energy transfer, thus maintaining the stability of the DC-DC converter output voltage.

[0070] Meanwhile, if the DC-DC converter is overloaded or overcurrented, the current detection CS sampling voltage signal increases and exceeds the threshold of 0.5V. The drive signal of the RSS3802QRH chip will be intermittently shut off to protect the circuit from being burned out.

[0071] The secondary-primary side control and signal magnetic isolation transmission circuit includes RS1010BCD and RS1010ACD chips.

[0072] The RS1010BCD and RS1010ACD chips feature built-in magnetically isolated drive signal transmission. The RS1010BCD chip transmits drive signals from the secondary-side master controller RSS3802QRH chip to the RS1010ACD chip, thereby controlling the power devices. Both chips have built-in magnetically isolated drive signal transmission capabilities with an isolation withstand voltage exceeding 500V, enabling magnetically isolated drive signal transmission.

[0073] The working principle of this converter when applied to a switching power supply is as follows:

[0074] In the primary-side control circuit, the input voltage is regulated by the first Zener diode Z1, then amplified by a Darlington transistor through transistors Q9 and Q3 to obtain a DC regulated power supply PVCC = 14-16V. Simultaneously, the auxiliary windings Z13-Z14 from the transformer are rectified by D4 to provide power after startup, reducing the power supply load on transistors Q9 and Q3. PVCC is regulated by diode Z2 and amplified by a second stage of current amplification via Q4 and Q10, outputting the primary-side DC power supply level VCC. This VCC powers the primary-side isolation drive control chip RS1010ACD and also serves as the power supply for the RCC self-excited push-pull magnetically isolated power supply circuit.

[0075] In the RCC self-excited push-pull magnetically isolated power supply circuit, the winding turns ratio NP:NS:NZ=12:2:14. The VCC DC level is alternately turned on by Q5 and Q6, forming two complementary square waves between the two windings X3-X4 and X5-X6 on the primary side of the magnetically isolated power supply transformer. The square wave signal is magnetically induced to generate two complementary square waves in the secondary windings Y5-Y6 and Y7-Y8. The two square waves are combined to form the DC signal on the secondary side, thus obtaining the secondary DC power supply SVCC=14~15V. The above process realizes the magnetically isolated power supply required by the switching power supply.

[0076] In the secondary-side main control chip circuit, the values ​​of resistors R45 and R44 are set so that the EN voltage is ≥1.13V during operation and ≤1.13V during disable, thus achieving the disable function. Based on the VOUT setting, the OVP voltage is set to ≤1.19V during operation and ≥1.2V during overvoltage to achieve overvoltage protection. The remaining parameters use generally recommended external parameters for the chip.

[0077] In the current sampling circuit, the turns ratio of CT1 coil and the resistance values ​​of R12 and R13 are set to ensure that the sampling voltage is ≤0.5V. At the same time, the circuit loop parameters are adjusted according to the actual situation. Here, C27=220pF, C24=470nF, and R24=200Ω to achieve stable current sampling control and overcurrent protection function.

[0078] In the primary-secondary side control and magnetically isolated signal transmission circuit, the RS1010BCD chip acts as an isolated driver transmitter, and the primary-side isolated driver control chip RS1010ACD acts as an isolated driver receiver. The chip's drive signal OUTA is transmitted through the secondary-side isolated driver chip RS1010BCD to the primary-side isolated control chip RS1010ACD, thereby controlling the on / off state of the primary-side MOSFET Q7 and performing chopping. The primary and secondary side ground lines are not connected, resulting in a small drive signal transmission delay (approximately 80ns), no signal distortion, and no impact on loop control and feedback. This process achieves the isolated signal control and transmission functions of the secondary-primary side control and magnetically isolated signal transmission circuit.

[0079] In this embodiment, the secondary-side main control chip circuit uses the RSS3802QRH model chip, the primary-side isolation drive control chip uses the RS1010ACD model chip, and the secondary-side isolation drive control chip uses the RS1010BCD model chip. All three chips (RSS3802QRH, RS1010ACD, and RS1010BCD) possess radiation resistance characteristics, and the power supply uses a magnetically isolated power supply method. This achieves the radiation resistance requirement.

[0080] Other features include: overvoltage protection can be configured by properly controlling the values ​​of resistors R50 and R51; overtemperature protection can be configured by replacing R51 with a positive temperature coefficient thermistor; the loop response speed at the COMP terminal can be adjusted to adapt to the current sampling feedback signal by adjusting the values ​​of R24, C31, and C27; the output voltage can be adjusted by adjusting the values ​​of resistors R39, R36, and R0; the overcurrent protection point can be adjusted by adjusting the values ​​of R12 and R13 and the number of turns of CT1, and cycle-by-cycle hiccup protection is implemented when the voltage at the CS pin is greater than 0.5V; adjusting capacitor C28 at the SS pin can adjust the hiccup restart time and startup delay time; and adjusting the value of R27 at the RT pin can adjust the transmission frequency of the chip drive signal OUTA.

[0081] Of particular note is that, because the RSS3802QRH chip is placed on the secondary side and directly receives the feedback signal from the FB pin, compared to previous magnetic feedback circuits, fewer components are used and the circuit is shorter, reducing unnecessary interference in the loop. Furthermore, the influence of temperature on the characteristics of the magnetic ring used in the magnetic feedback is no longer a concern, resulting in a fast and stable loop response. The COMP terminal can achieve good loop adjustment over a wide temperature range of -55℃ to 125℃, enabling the DC-DC converter to achieve fast and stable dynamic loop characteristics.

[0082] This invention provides a magnetically isolated and radiation-resistant DC-DC converter. Through an RCC self-excited push-pull magnetically isolated power supply circuit, it powers the secondary and primary-side isolated drive control circuits and the secondary-side main control chip circuit, thus providing a magnetically isolated auxiliary power supply. The secondary-primary side control and signal magnetically isolated transmission circuits enable magnetically isolated transmission control of the drive signal. The secondary-side main control chip circuit enables overvoltage and current sampling detection functions. Radiation resistance is achieved through the selection of a radiation-resistant chip and a magnetically isolated power supply. The switching power supply exhibits fast response speed under various operating conditions, smooth waveform recovery, minimal ringing, and stable loop state. It eliminates the need for an additional radiation-resistant auxiliary power chip and a separate auxiliary power supply, resulting in a simple circuit structure that reduces costs and increases power density. It is suitable for various magnetically isolated switching power supplies.

[0083] This invention provides a magnetically isolated and radiation-resistant DC-DC converter. Through an RCC self-excited push-pull magnetically isolated power supply circuit, it powers the secondary and primary-side isolated drive control circuits and the secondary-side main control chip circuit, thus providing a magnetically isolated auxiliary power supply. The secondary-primary side control and signal magnetically isolated transmission circuits enable magnetically isolated transmission control of the drive signal. The secondary-side main control chip circuit enables overvoltage and current sampling detection functions. Radiation resistance is achieved through the selection of a radiation-resistant chip and a magnetically isolated power supply. The switching power supply exhibits fast response speed under various operating conditions, smooth waveform recovery, minimal ringing, and stable loop state. It eliminates the need for an additional radiation-resistant auxiliary power chip and a separate auxiliary power supply, resulting in a simple circuit structure that reduces costs and increases power density. It is suitable for various magnetically isolated switching power supplies.

[0084] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetically isolated and radiation-resistant DC-DC converter, characterized in that, include: Secondary-primary side control and signal magnetic isolation transmission circuit, RCC self-excited push-pull magnetic isolation power supply circuit, current sampling circuit and secondary-side main control chip circuit; The secondary-primary side control and signal magnetic isolation transmission circuit has a primary side isolation drive control circuit and a secondary side isolation drive control circuit. The RCC self-excited push-pull magnetic isolation power supply circuit supplies power to the primary side isolation drive control circuit, the secondary side isolation drive control circuit, and the secondary side main control chip circuit in the secondary-primary side control and signal magnetic isolation transmission circuit. The primary side isolation drive control circuit is connected to the primary side of the magnetic isolation power supply transformer, and the secondary side isolation drive control circuit is connected to the secondary side of the magnetic isolation power supply transformer. The secondary-primary side control and signal magnetic isolation transmission circuit is connected to the secondary-side main control chip circuit, and the secondary-side main control chip circuit is connected to the current sampling circuit. The RCC self-excited push-pull magnetically isolated power supply circuit includes: The primary winding of the magnetically isolated power supply transformer has a first winding X3-X4X5-X6 and a second winding X7-X8X9-X10. In the first winding X3-X4X5-X6, the X3 winding coil is connected with the X4X5 winding coil at the same end to the opposite end, the X4X5 winding coil is connected with the X6 winding coil at the same end to the opposite end, and the X4X5 winding coil is the center tap of the X3-X4 winding coil and the X5-X6 winding coil. In the second winding X7-X8X9-X10, the X7 winding coil is opposite to the X8X9 winding coil, the X8X9 winding coil is opposite to the X10 winding coil, and the X8X9 winding coil is the center tap of the X7-X8 winding coil and the X8-X9 winding coil. The secondary windings of the magnetically isolated power supply transformer are Y5-Y6Y7-Y8; In the secondary winding Y5-Y6Y7-Y8, the Y5 winding coil is connected with the Y6Y7 winding coil at the same end to the opposite end, and the Y6Y7 winding coil is connected with the Y8 winding coil at the same end to the opposite end. The Y6Y7 winding coil is the center tap of the Y5-Y6 winding coil and the Y6-Y7 winding coil.

2. The magnetically isolated and radiation-resistant DC-DC converter according to claim 1, characterized in that, The secondary main control chip is an RSS3802QRH model chip.

3. The magnetically isolated and radiation-resistant DC-DC converter according to claim 1, characterized in that, The primary-side isolation drive control chip is an RS1010BCD model chip.

4. The magnetically isolated and radiation-resistant DC-DC converter according to claim 1, characterized in that, The secondary isolation drive control chip is an RS1010ACD model chip.

5. The magnetically isolated and radiation-resistant DC-DC converter according to claim 1, characterized in that, The RCC self-excited push-pull magnetically isolated power supply circuit also includes: The fifth PNP transistor Q5, the sixth PNP transistor Q6, the tenth resistor R10, the eleventh resistor R11, the eighth resistor R8, the eleventh capacitor C11, the fourteenth capacitor C14, the seventh diode D7, and the eighth diode D8. The collector (C) of the fifth PNP transistor Q5 is connected to the X3 winding of the first winding X3-X4X5-X6, the emitter (E) is connected to the primary ground (PGND), the base (B) is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to the X10 winding of the second winding X7-X8X9-X10. The collector (C) of the fifth PNP transistor Q6 is connected to the X6 winding end of the first winding X3-X4X5-X6, the emitter (E) is connected to the PGND terminal, the base (B) is connected to one end of the tenth resistor R10, and the other end of the tenth resistor R10 is connected to the X7 winding end of the second winding X7-X8X9-X10. The eighth resistor R8 is connected to one end of the eleventh capacitor C11, and the connected end is connected to the X8X9 end of the primary winding X7-X8X9-X10 of the magnetic isolation power supply transformer. The other end of the eleventh capacitor C11 is connected to the primary ground PGND end, and the other end of the eighth resistor R8 is connected to the X4X5 winding end of the first winding X3-X4X5-X6. At the same time, the X4X5 winding end is connected to the primary power supply VCC end. The anode of the seventh diode D7 is connected to the Y5 winding of the secondary winding Y5-Y6Y7-Y8 of the magnetically isolated power supply transformer, and the cathode is connected to the eighth diode D8. The anode of the eighth diode D8 is connected to the Y8 winding of the secondary winding Y5-Y6Y7-Y8 of the magnetically isolated power supply transformer, and the cathode is connected to the cathode of the seventh diode D7. The Y6Y7 winding of the second winding Y5-Y6Y7-Y8 is connected to the secondary ground GND.

6. The magnetically isolated and radiation-resistant DC-DC converter according to claim 5, characterized in that, The primary-side power supply VCC of the RCC self-excited push-pull magnetically isolated power supply circuit charges the X8X9 winding of the second winding X7-X8X9-X10 through the eighth resistor R8 and the eleventh capacitor C11. The X8X9 winding charges the base of the fifth transistor Q5 and the sixth transistor Q6 through the eleventh resistor R11 and the tenth resistor R10. Due to the inconsistency of the base injection current of Q5 and Q6, one of Q5 and Q6 turns on before the other. If Q5 turns on first, that is, X10 is high level first. Since the winding polarity of the primary winding of the magnetically isolated power supply transformer X10 and X3 are opposite, X3 is low level, that is, Q5 When the transistor Q5 is conducting, the transistor Q6 is not conducting because X7 is at a low level and X6 is at a high level. This is equivalent to the induced electromotive force generated when Q5 is conducting suppressing the conduction of Q6. When the rate of change of the conduction current of Q5 is 0, according to Lenz's law, the electromotive force will reverse, and Q6 will conduct, thus suppressing the conduction of Q5. This process repeats, achieving the alternating conduction of the two transistors and realizing the purpose of self-excited oscillation. This is equivalent to the primary side of the magnetically isolated power supply transformer providing an oscillating square wave signal, inducing two complementary square waves on the secondary side. These square waves are synthesized by D7 and D8 to form a stable secondary DC power supply level SVCC, which powers the secondary main control chip circuit.

7. The magnetically isolated and radiation-resistant DC-DC converter according to claim 2, characterized in that, The secondary-side main control chip uses the RSS3802QRH model chip, which integrates the disable function, overvoltage protection function, and current sampling and detection function. The secondary-side main control chip circuit includes: The forty-fifth resistor R45, the forty-fourth resistor R44; the fiftieth resistor R50, the fifty-first resistor R51, and the twenty-second resistor R22; The forty-fifth resistor R45 is connected to the secondary power supply SVCC level, and its other end is connected to the forty-fourth resistor R44. The other end of R44 is connected to the secondary side GND. The common connection terminal of R45 and R44 is connected to the disable pin EN of the RSS3802QRH chip. The disable / enable function of the RSS3802QRH chip is realized by setting the resistance values ​​of R45 and R44. The fiftieth resistor R50 is connected at one end to the output voltage VOUT terminal and at the other end to the fifty-first resistor R51. R51 is also connected to the other end of the output voltage VOUT terminal. One end of the resistor R50 is connected to the secondary ground (GND). The common connection of R50 and R51 is connected to the overvoltage protection pin (OVP) of the RSS3802QRH chip. The overvoltage protection function of the RSS3802QRH chip is achieved by setting the resistance values ​​of R50 and R51. One end of the 22nd resistor R22 is connected to the current sampling circuit, and the other end is connected to the CS pin of the RSS3802QRH chip. The signal transmitted from the CS pin is sampled and detected by the built-in circuit of the RSS3802QRH.

8. The magnetically isolated and radiation-resistant DC-DC converter according to claim 1, characterized in that, The current sampling circuit includes: The sixth diode D6, the twelfth resistor R12, the thirteenth resistor R13, the fifteenth resistor R15, and the transformer coil winding CT1; The fifteenth resistor R15 and the sixth diode D6 convert the primary circuit current collected by the transformer coil winding into a voltage signal through the twelfth resistor R12 and the thirteenth resistor R13, and transmit it to the current detection CS terminal of the RSS3802QRH chip. The RSS3802QRH chip controls the energy transfer according to the load power of the magnetically isolated and radiation-resistant DC-DC converter. When the power of the DC-DC converter increases, the voltage signal sampled by the current detection CS increases, and the RSS3802QRH chip adjusts the duty cycle of the drive signal accordingly to increase energy transfer. Conversely, it decreases the duty cycle to reduce energy transfer in order to maintain the stability of the DC-DC converter output voltage.

9. The magnetically isolated and radiation-resistant DC-DC converter according to claim 3 or 4, characterized in that, The secondary-primary side control and signal magnetic isolation transmission circuit includes an RS1010BCD chip and an RS1010ACD chip. The RS1010BCD and RS1010ACD chips have built-in magnetic isolation drive signal transmission functions. The RS1010BCD chip can transmit the drive signal of the secondary-side main control RSS3802QRH chip to the RS1010ACD chip, thereby controlling the operation of the power device. The RS1010BCD and RS1010ACD chips have built-in magnetic isolation drive signal transmission functions.

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