Low-temperature-resistant DCDC power supply control circuit and low-temperature-resistant power supply equipment

Abstract

The embodiment of the utility model provides a low-temperature-resistant DCDC power supply control circuit and low-temperature-resistant power supply equipment. The low-temperature-resistant DCDC power supply control circuit comprises a surge limiting sub-circuit, a low-temperature standby path sub-circuit and a switch control sub-circuit, the surge limiting sub-circuit is arranged between the positive input end of the power supply and the DCDC power supply; the switch control sub-circuit is arranged between the negative input end of the power supply and the DCDC power supply; and the low-temperature standby pass sub-circuit is connected in parallel with the surge limiting sub-circuit. A second current path can be provided under a low-temperature condition, so that the power supply module can be smoothly started, and the limitation of adopting a heating device, a pre-charging circuit and other methods in the prior art is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic circuit, in particular to a low-temperature-resistant DCDC power supply control circuit and a low-temperature-resistant power supply device. BACKGROUND

[0002] With the wide application of electronic devices in low-temperature environments, especially in the fields of automobiles, aerospace, military and outdoor equipment, the requirements for power supply systems are also increasing. Especially for DCDC power modules, the characteristics of NTC thermistors often affect the normal start of the power supply, causing the circuit to not work as expected. Therefore, how to improve the start-up performance of DCDC power modules in low-temperature environments has become a key problem in current power supply control technology.

[0003] At present, in the prior art, NTC resistors are widely used in power supply control circuits, and their main function is to limit the inrush current during startup. The resistance value of the NTC resistor will gradually decrease as the temperature rises, so during normal operation, the NTC resistor has little effect on the current. However, in a low-temperature environment, the resistance value of the NTC resistor will increase significantly, resulting in a large voltage drop during startup, so that the DCDC power module cannot provide enough starting current, which may cause the power module to fail to start and affect the normal operation of the system. CONTENT OF THE INVENTION

[0004] Therefore, the purpose of the present application is to provide a low-temperature-resistant DCDC power supply control circuit and a low-temperature-resistant power supply device that can provide a second current path under low-temperature conditions, thereby ensuring that the power module can start smoothly and avoiding the limitations of the prior art methods such as using heating devices and pre-charge circuits.

[0005] In a first aspect, the embodiments of the present application provide a low-temperature-resistant DCDC power supply control circuit, which comprises a surge limiting sub-circuit, a low-temperature standby path sub-circuit and a switch control sub-circuit.

[0006] The surge limiting sub-circuit is arranged between the positive input end of the power supply and the DCDC power supply.

[0007] The switch control sub-circuit is arranged between the negative input end of the power supply and the DCDC power supply.

[0008] The low-temperature standby path sub-circuit is connected in parallel with the surge limiting sub-circuit.

[0009] In combination with the first aspect, the embodiments of the present application provide a first possible implementation manner of the first aspect, wherein the surge limiting sub-circuit comprises a thermistor.

[0010] One end of the thermistor is connected to the positive input terminal of the power supply;

[0011] The other end of the thermistor is connected to the DC-DC power supply.

[0012] In conjunction with the first aspect, this application provides a second possible implementation of the first aspect, wherein the surge limiting sub-circuit further includes an energy storage capacitor;

[0013] The energy storage capacitor is connected in parallel with the negative temperature coefficient thermistor.

[0014] In conjunction with the first aspect, this application provides a third possible implementation of the first aspect, wherein the cryogenic backup circuit includes a Zener diode and a first resistor;

[0015] The anode of the Zener diode is connected to the connection point between the negative temperature coefficient thermistor and the DC-DC power supply.

[0016] The cathode of the Zener diode is connected to one end of the first resistor, and the other end of the first resistor is connected to the connection point between the negative temperature coefficient thermistor and the positive input terminal of the power supply.

[0017] In conjunction with the first aspect, this application provides a fourth possible implementation of the first aspect, wherein the switch control sub-circuit includes a MOS transistor;

[0018] The source of the MOSFET is connected to the negative input terminal of the power supply;

[0019] The drain of the MOS transistor is connected to the DC-DC power supply.

[0020] In conjunction with the first aspect, this application provides a fifth possible implementation of the first aspect, wherein the gate of the MOS transistor is connected to a power control signal.

[0021] In conjunction with the first aspect, this application provides a sixth possible implementation of the first aspect, wherein the switch control sub-circuit further includes a reverse protection diode;

[0022] The anode of the anti-reverse diode is connected to the source of the MOS transistor;

[0023] The cathode of the anti-reverse diode is connected to the negative input terminal of the power supply.

[0024] In conjunction with the first aspect, this application provides a seventh possible implementation of the first aspect, wherein the low-temperature resistant DC-DC power control circuit further includes a filter capacitor;

[0025] The filter capacitor is connected between the positive output terminal and the negative output terminal of the DC-DC power supply.

[0026] In conjunction with the first aspect, this application provides an eighth possible implementation of the first aspect, wherein the thermistor is a negative temperature coefficient thermistor.

[0027] Secondly, embodiments of this application provide a low-temperature resistant power supply device, such as the low-temperature resistant DC-DC power control circuit described in any of the above embodiments.

[0028] This application provides a low-temperature resistant DC-DC power supply control circuit and a low-temperature resistant power supply device, including a surge limiting subcircuit, a low-temperature backup path subcircuit, and a switch control subcircuit. The surge limiting subcircuit is disposed between the positive input terminal of the power supply and the DC-DC power supply; the switch control subcircuit is disposed between the negative input terminal of the power supply and the DC-DC power supply; the low-temperature backup path subcircuit is connected in parallel with the surge limiting subcircuit. This provides a second current path under low-temperature conditions, thereby ensuring that the power module can start smoothly and avoiding the limitations of existing technologies that use heating devices and pre-charging circuits. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 One of the structural schematic diagrams of a low-temperature resistant DC-DC power supply control circuit provided in this embodiment of the present invention;

[0031] Figure 2 A second schematic diagram of a low-temperature resistant DC-DC power supply control circuit provided for an embodiment of this utility model;

[0032] Figure 3 A third schematic diagram of a low-temperature resistant DC-DC power supply control circuit provided for an embodiment of this utility model;

[0033] Figure 4 This is a structural schematic diagram of a low-temperature resistant power supply device provided for an embodiment of the present utility model.

[0034] Icons: 10-Surge limiting sub-circuit; 20-Low temperature backup path sub-circuit; 30-Switch control sub-circuit; 11-Thermistor; 12-Energy storage capacitor; 21-Zenith diode; 22-First resistor; 31-MOSFET; 32-Reverse protection diode; 40-Filter capacitor. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0038] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0039] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0040] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0041] In existing technologies, NTC resistors are widely used in power control circuits, primarily to limit inrush current during startup. The resistance of an NTC resistor gradually decreases with increasing temperature; therefore, under normal operating conditions, its impact on current is relatively small. However, at low temperatures, the resistance of an NTC resistor increases significantly, resulting in a large voltage drop during startup. This can prevent the DC-DC power module from receiving sufficient startup current, potentially causing it to fail to start and affecting the normal operation of the system.

[0042] This application provides a low-temperature resistant DC-DC power supply control circuit and a low-temperature resistant power supply device, including a surge limiting subcircuit, a low-temperature backup path subcircuit, and a switch control subcircuit. The surge limiting subcircuit is disposed between the positive input terminal of the power supply and the DC-DC power supply; the switch control subcircuit is disposed between the negative input terminal of the power supply and the DC-DC power supply; the low-temperature backup path subcircuit is connected in parallel with the surge limiting subcircuit. This provides a second current path under low-temperature conditions, thereby ensuring that the power module can start smoothly and avoiding the limitations of existing technologies that use heating devices and pre-charging circuits.

[0043] Please see Figure 1 , Figure 1 This is one of the structural schematic diagrams of a low-temperature resistant DC-DC power supply control circuit provided in this embodiment.

[0044] like Figure 1 As shown in the figure, the low-temperature resistant DC-DC power supply control circuit provided in this embodiment includes: a surge limiting sub-circuit 10, a low-temperature backup path sub-circuit 20, and a switch control sub-circuit 30.

[0045] Here, the surge limiting sub-circuit 10 is located between the positive input terminal VIN+ of the power supply and the DC-DC power supply; the switch control sub-circuit 30 is located between the negative input terminal VIN- of the power supply and the DC-DC power supply; and the low-temperature backup path sub-circuit 20 is connected in parallel with the surge limiting sub-circuit 10.

[0046] In practical implementation, the surge limiting sub-circuit 10 is mainly used to limit the surge current of the power module during startup, preventing large current surges from damaging the circuit. The low-temperature backup path sub-circuit 20 is mainly used to provide a backup current path when the resistance of the surge limiting sub-circuit 10 is too high at low temperatures, ensuring that the DC-DC power module can still be provided with startup current when the resistance of the surge limiting sub-circuit 10 is too high.

[0047] The DC-DC power module is responsible for converting the input voltage into a stable output voltage; the switch control sub-circuit 30 is responsible for controlling the power module's on and off states. When the power needs to be turned on, the switch control sub-circuit 30 conducts to allow current to flow into the circuit, thus starting the entire power module.

[0048] This application provides a low-temperature resistant DC-DC power supply control circuit, including a surge limiting subcircuit, a low-temperature backup path subcircuit, and a switch control subcircuit. The surge limiting subcircuit is located between the positive input terminal of the power supply and the DC-DC power supply. The switch control subcircuit is located between the negative input terminal of the power supply and the DC-DC power supply. The low-temperature backup path subcircuit is connected in parallel with the surge limiting subcircuit. This circuit provides a second current path under low-temperature conditions, ensuring the power module can start smoothly and avoiding the limitations of existing technologies that use heating devices and pre-charging circuits.

[0049] Please see Figure 2 , Figure 2 This is the second schematic diagram of a low-temperature resistant DC-DC power supply control circuit provided in this embodiment.

[0050] like Figure 2 As shown in the figure, another low-temperature resistant DC-DC power supply control circuit provided in this embodiment includes: a surge limiting sub-circuit 10, a low-temperature backup path sub-circuit 20, and a switch control sub-circuit 30. The surge limiting sub-circuit 10 includes a thermistor 11 and an energy storage capacitor 12; the low-temperature backup path sub-circuit 20 includes a Zener diode 21 and a first resistor 22.

[0051] Here, one end of the thermistor 11 is connected to the positive input terminal VIN+ of the power supply; the other end of the thermistor 11 is connected to the DC-DC power supply. The energy storage capacitor 12 is connected in parallel with the thermistor 11. The anode of the Zener diode 21 is connected to the connection point between the thermistor 11 and the DC-DC power supply; the cathode of the Zener diode 21 is connected to one end of the first resistor 22, and the other end of the first resistor 22 is connected to the connection point between the thermistor 11 and the positive input terminal VIN+ of the power supply.

[0052] It should be noted that the thermistor 11 is preferably a negative temperature coefficient thermistor.

[0053] In practical implementation, thermistor 11 is mainly used to limit the inrush current of the power module during startup. When the power supply is first started, the resistance of thermistor 11 is relatively high, thus absorbing the surge current generated when the internal capacitors of the power supply are charging, preventing damage to the circuit from large current surges. When the resistance of thermistor 11 is too high at low temperatures, the Zener diode 21 and the first resistor 22 provide a backup current path, ensuring that the DC-DC power module can still be supplied with startup current even when the resistance of thermistor 11 is too high.

[0054] Here, the Zener diode 21 will be reverse-broken down when the resistance of the thermistor 11 increases, resulting in an excessive voltage drop, thus forming a second current path.

[0055] Please see Figure 3 , Figure 3 This is the third schematic diagram of a low-temperature resistant DC-DC power supply control circuit provided in this embodiment.

[0056] like Figure 3 As shown in the diagram, another low-temperature resistant DC-DC power supply control circuit provided in this embodiment includes: a surge limiting sub-circuit 10, a low-temperature backup path sub-circuit 20, and a switch control sub-circuit 30. The surge limiting sub-circuit 10 includes a thermistor 11 and an energy storage capacitor 12; the low-temperature backup path sub-circuit 20 includes a Zener diode 21 and a first resistor 22. The switch control sub-circuit 30 includes a MOSFET 31 and a reverse-biased diode 32; the low-temperature resistant DC-DC power supply control circuit also includes a filter capacitor 40.

[0057] Here, the source of MOSFET 31 is connected to the negative input terminal VIN- of the power supply; the gate of MOSFET 31 is connected to the power control signal POWER_CTRL. The drain of MOSFET 31 is connected to the DC-DC power supply. The anode of the reverse protection diode 32 is connected to the source of MOSFET 31; the cathode of the reverse protection diode 32 is connected to the negative input terminal VIN- of the power supply. The filter capacitor 40 is connected between the positive output terminal VOUT+ and the negative output terminal VOUT- of the DC-DC power supply.

[0058] In practical implementation, the DC-DC power module is responsible for converting the input voltage into a stable output voltage. The filter capacitor 40 is used for filtering, removing noise and fluctuations from the output voltage, and providing a smooth DC voltage. The DC-DC power module receives current from the thermistor 11 or the cryogenic backup circuit 20 at its input terminal and outputs the converted voltage.

[0059] Furthermore, MOSFET 31 is responsible for controlling the power module's on and off states. When power needs to be turned on, MOSFET 31 conducts, allowing current to flow into the circuit and starting the entire power module. Anti-reverse diode 32 is used to prevent the circuit from being affected by reverse voltage, protecting the circuit from potential reverse voltage damage.

[0060] In practical applications, the working principle of the low-temperature resistant DC-DC power supply control circuit is as follows: When the power module needs to be turned on, the power control signal controls the MOSFET 31 to conduct, and current begins to flow into the circuit. At this time, the thermistor 11 has a high resistance, which is used to absorb the surge current generated when the capacitor inside the DC-DC power module is charging, limiting the current surge during startup and protecting the components in the circuit. In low-temperature environments, the resistance of the thermistor 11 becomes very large, resulting in an excessively high voltage drop, which may prevent the DC-DC power module from starting. To solve this problem, a Zener diode 21 and a first resistor 22 are added to the circuit. When the resistance of the thermistor 11 increases and the voltage drop becomes too high, the Zener diode 21 will be reverse-biased and broken down. The Zener diode 21 and the first resistor 22 form a low-temperature backup circuit sub-circuit 20 to provide the current required for power startup.

[0061] Furthermore, once the DC-DC power module starts up, the thermistor 11 gradually heats up due to the current flowing through it, and its resistance gradually decreases. As the thermistor 11 decreases, the voltage drop also decreases, eventually becoming insufficient to keep the Zener diode 21 in a reverse breakdown state. At this point, the low-temperature backup circuit 20 (through the Zener diode 21 and the first resistor 22) stops working, and the circuit returns to normal operation.

[0062] This circuit design ensures that even in low-temperature environments, the startup problem caused by the increased resistance of thermistor 11 can be resolved, and the power module can start normally. The current-carrying capacity of the low-temperature backup circuit 20 can be flexibly controlled by adjusting the resistance value of the first resistor 22 and the breakdown voltage of the Zener diode 21 to adapt to different operating conditions. The energy storage capacitor 12 can absorb the inrush current during startup, preventing the Zener diode 21 from being broken down by the inrush current at the moment of power-on, thus protecting the circuit.

[0063] Please see Figure 4 , Figure 4 This is a schematic diagram of a low-temperature power supply device provided in this embodiment.

[0064] like Figure 4 As shown, the cryogenic power supply equipment includes, for example... Figures 1-3 The low-temperature resistant DC-DC power supply control circuit shown in any of the examples.

[0065] This application provides a low-temperature resistant DC-DC power supply control circuit and a low-temperature resistant power supply device, including a surge limiting subcircuit, a low-temperature backup path subcircuit, and a switch control subcircuit. The surge limiting subcircuit is disposed between the positive input terminal of the power supply and the DC-DC power supply; the switch control subcircuit is disposed between the negative input terminal of the power supply and the DC-DC power supply; the low-temperature backup path subcircuit is connected in parallel with the surge limiting subcircuit. This provides a second current path under low-temperature conditions, thereby ensuring that the power module can start smoothly and avoiding the limitations of existing technologies that use heating devices and pre-charging circuits.

[0066] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A low temperature tolerant DC-DC power supply control circuit, characterized by, The surge limiting sub-circuit, the low-temperature backup path sub-circuit and the switch control sub-circuit are included. The surge limiting sub-circuit is arranged between the positive input end of the power supply and the DCDC power supply. The switch control sub-circuit is arranged between the negative input end of the power supply and the DCDC power supply. The low-temperature backup path sub-circuit is connected in parallel with the surge limiting sub-circuit.

2. The low temperature tolerant DC-DC power supply control circuit according to claim 1, characterized in that, The surge limiting sub-circuit includes a thermistor. One end of the thermistor is connected to the positive input end of the power supply. The other end of the thermistor is connected to the DCDC power supply.

3. The low temperature tolerant DC-DC power supply control circuit of claim 2, wherein, The surge limiting sub-circuit further includes an energy storage capacitor. The energy storage capacitor is connected in parallel with the thermistor.

4. The low temperature tolerant DC-DC power supply control circuit of claim 2, wherein, The low-temperature backup path sub-circuit includes a zener diode and a first resistor. The anode of the zener diode is connected to a connection point between the thermistor and the DCDC power supply. The cathode of the zener diode is connected to one end of the first resistor, and the other end of the first resistor is connected to a connection point between the thermistor and the positive input end of the power supply.

5. The low temperature tolerant DC-DC power supply control circuit of claim 1, wherein, The switch control sub-circuit includes a MOS tube. The source of the MOS tube is connected to the negative input end of the power supply. The drain of the MOS tube is connected to the DCDC power supply.

6. The low-temperature-resistant DCDC power supply control circuit according to claim 5, wherein: The gate of the MOS tube is connected to a power supply control signal.

7. The low temperature tolerant DC-DC power supply control circuit of claim 5, wherein, The switch control sub-circuit further includes an anti-reverse diode. The anode of the anti-reverse diode is connected to the source of the MOS tube. The cathode of the anti-reverse diode is connected to the negative input end of the power supply.

8. The low temperature tolerant DC-DC power supply control circuit of claim 1, wherein, The low-temperature-resistant DCDC power supply control circuit further includes a filter capacitor. The filter capacitor is connected between the positive output end of the DCDC power supply and the negative output end of the DCDC power supply.

9. The low-temperature-resistant DCDC power supply control circuit according to claim 2, wherein: The thermistor is a negative temperature coefficient thermistor.

10. A low temperature tolerant power supply device, characterized by, The low-temperature-resistant DCDC power supply control circuit includes the low-temperature-resistant DCDC power supply control circuit according to any one of claims 1-8.

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