A dual redundant power supply DC / DC circuit with safety protection function

Abstract

The present invention discloses a dual redundant power supply DC / DC circuit with a safety protection function, including: a power gating and short circuit prevention sub-circuit and a DC / DC sub-circuit; in the power gating and short circuit prevention sub-circuit, two power input sensing ports of a field effect tube gating controller are respectively connected to two voltage sources, two power output sensing ports are respectively connected to parallel output terminals, two driving ports are correspondingly connected to the control terminals of two power field effect tubes, the input terminals of the two power field effect tubes are correspondingly connected to two voltage sources, the output terminals are connected to the parallel output terminals, and the parallel output terminals are connected to the input terminals of the DC / D sub-circuit; the switching of dual redundant power supply is realized by the field effect tube gating controller. The technical solution of the present invention solves the problem that the power supply switching mode of the existing gating diode is very large because the voltage and power loss on the diode are very large, which leads to the risk of burning of the entire circuit due to the short circuit of the diode.

Description

Technical Field

[0001] The present invention relates to the field of, but is not limited to, electromechanical control technology for airborne computers, and in particular to a dual redundant power supply DC / DC circuit with a safety protection function. Background Art

[0002] With the improvement of the safety requirements of aircraft onboard equipment, the reliability requirements for onboard computers are getting higher and higher, and the technical requirements for dual redundant power supply are put forward for its component modules to ensure that the onboard computers can still work normally in the event of partial power loss.

[0003] The traditional method of switching the power supply by the gate diode results in very large voltage and power loss on the diode, and there is a risk of the diode being short-circuited and burned out. Summary of the invention

[0004] Purpose of the invention: In order to solve the problems in the background technology, the present invention proposes a dual redundant power supply DC / DC circuit with a safety protection function to solve the problem of the existing power supply switching method of the selection diode. Since the voltage and power loss on the diode are very large, the entire circuit is at risk of burning due to a diode short circuit.

[0005] The technical solution of the present invention: The embodiment of the present invention proposes a dual redundant power supply DC / DC circuit with a safety protection function, including: a power supply gating and short circuit prevention subcircuit and a DC / DC subcircuit;

[0006] The power supply gating and short circuit prevention subcircuit includes: a field effect tube gating controller, two power field effect tubes, and two fuses;

[0007] Wherein, the two power input sensing ports of the field effect tube gating controller are connected to two voltage sources one by one, the two power output sensing ports are connected to the parallel output terminals respectively, the two driving ports are connected to the control terminals of the two power field effect tubes one by one, the input terminals of the two power field effect tubes are connected to the two voltage sources one by one, the output terminals are connected to the parallel output terminals through a fuse respectively, and the parallel output terminals are connected to the input terminals of the DC / D sub-circuit;

[0008] The field effect transistor gating controller is used to monitor the voltage difference between two power input sensing ports and their corresponding power output sensing ports to determine whether to enable one of the power field effect transistors and simultaneously disable the other power field effect transistor, thereby realizing the switching of dual redundant power supply.

[0009] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above,

[0010] The field effect transistor gating controller is specifically used to monitor the voltage difference between the two power input sensing ports and their corresponding power output sensing ports, shut down the power field effect transistor on the input voltage source side that is lower than the parallel output terminal voltage Vout, and turn on the power field effect transistor on the input voltage source side that is higher than the parallel output terminal voltage Vout, thereby realizing automatic switching judgment and gating of dual redundant power supplies.

[0011] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above, the connection ports of the field effect transistor gating controller include: two power input sensing ports, VIN1 and VIN2; two power output sensing ports, VOUT1 and VOUT2; two drive ports, GATE1 and GATE2; input enable ports EN1 and EN2, both of which are grounded;

[0012] Among them, the first voltage source 5V1 is connected to VIN1 and the source S1 and VIN1 of the power field effect tube 1 respectively, the second voltage source 5V2 is connected to VIN2 and the source S2 of the power field effect tube 2 respectively, VOUT1 and VOUT2 are connected to the parallel output ends respectively, the gate G1 of the power field effect tube 1 is connected to GATE1, the drain D1 is connected to the front end of the fuse 1, the gate G2 of the power field effect tube 2 is connected to GATE2, the drain D2 is connected to the front end of the fuse 2, and the rear ends of the fuse 1 and the fuse 2 are respectively connected to the parallel output ends.

[0013] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above, the field effect transistor gating controller performs voltage difference monitoring, including:

[0014] respectively monitoring the voltage difference between the first voltage source 5V1 and the power output sensing port VOUT1, and the voltage difference between the second voltage source 5V2 and the power output sensing port VOUT2;

[0015] The field effect tube gating controller performs judgment and gating, including:

[0016] When the voltage Vout at the parallel output terminal is higher than the first voltage source 5V1 and lower than the second voltage source 5V2, the voltage of GATE2 is pulled up and the voltage of GATE1 is pulled down, thereby driving the power field effect transistor 2 to be turned on and the power field effect transistor 1 to be turned off, so that the second voltage source 5V2 is used as the power supply;

[0017] When the parallel output voltage Vout is higher than the second voltage source 5V2 and lower than the first voltage source 5V1, the GATE1 voltage will be pulled up and the GATE2 voltage will be pulled down, thereby driving the power field effect transistor 1 to be turned on and the power field effect transistor 2 to be turned off, so that the first voltage source 5V1 is used as the power supply.

[0018] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above,

[0019] The power field effect tube should be an N-channel field effect tube, and the impedance of the N-channel field effect tube when it is turned on is 0.8mΩ to 1.5mΩ, the maximum voltage drop when it is turned on when the voltage source is 5V and the load is 2A is 0.003V, and the maximum drain-source voltage is 25V.

[0020] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above,

[0021] The field effect transistor gating controller is also used for controlling the GATE1 voltage to be lowered and the field effect transistor 1 to be turned off when the first voltage source 5V1 is short-circuited to the ground and the parallel output terminal voltage Vout is higher than the voltage of the first voltage source 5V1; and for controlling the GATE2 voltage to be lowered and the field effect transistor 2 to be turned off when the second voltage source 5V2 is short-circuited to the ground and the parallel output terminal voltage Vout is higher than the voltage of the second voltage source 5V2.

[0022] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above,

[0023] Each of the fuses is connected between the drain of the corresponding power field effect tube and the subsequent DC / DC sub-circuit, and is used to cut off the path to which it is connected for protection when a short circuit occurs between the source and drain of the power field effect tube connected to the fuse.

[0024] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above,

[0025] The DC / DC subcircuit is configured as an output configurable DC / DC subcircuit, having multiple output paths, and each output path is provided with a corresponding configuration resistor, and the output voltage of the corresponding output path is configured by the configuration resistor; wherein the output voltage of each output path is configured to be the same voltage value or different voltage values.

[0026] Optionally, in the dual redundant power supply DC / DC circuit with safety protection function as described above, the DC / DC subcircuit specifically includes two output paths, the two output paths having two groups of input ports, Vin1 and Vin2; two groups of output ports, Vout1 and Vout2; two startup control ports, RUN1 and RUN2; two configuration ports, FB1 and FB2;

[0027] Wherein, each group of input ports is respectively connected to the parallel output terminals of the power gating and short circuit prevention sub-circuit, and each group of input ports is respectively connected to two parallel capacitors, for decoupling the output voltage Vout of the parallel output terminals and reducing jitter;

[0028] Each group of output ports is connected to three parallel capacitors to ensure the stability of power supply to the back-end power-consuming chips;

[0029] Each start control port is connected to the parallel output terminal of the power supply gating and short circuit prevention sub-circuit through a pull-up resistor, so as to enable the corresponding output path inside the DC / DC sub-circuit;

[0030] Each configuration port is grounded via a configuration resistor, and is used to configure the output voltage of the output path where the configuration port is located by configuring the resistance value of the configuration resistor.

[0031] Beneficial effects of the present invention: The embodiment of the present invention proposes a dual redundant power supply DC / DC circuit with a safety protection function. By reasonably designing the structure of the power gating and anti-short circuit sub-circuit, the field effect tube gating controller in the sub-circuit can monitor the voltage difference between the two power input sensing ports and the corresponding power output sensing ports, judge to select one of the power field effect tubes and turn off the other power field effect tube at the same time, so as to realize the switching of dual redundant power supply; in the sub-circuit, the on-resistance is reduced by using the power field effect tube, and the on-voltage drop is reduced; in addition, a fuse is arranged between the drain of the power field effect tube and the rear-stage DC / DC sub-circuit. When a short circuit occurs between the source and drain of the power field effect tube, especially when the power field effect tube is burned or short-circuited, and needs to be turned off but the field effect gating controller cannot turn off the power field effect tube, the fuse can cut off the path for protection to avoid the spread of the fault; furthermore, in the circuit, the output configurable DC / DC sub-circuit provides a configurable power output for the back-end power-consuming chip.

[0032] The dual redundant power supply DC / DC circuit provided by the embodiment of the present invention can not only judge, select and quickly switch the two external power supplies, and has short-circuit protection capability, but also can flexibly configure the output power supply according to the back-end power consumption chip, realize the single-board dual redundant power supply, reduce the use of additional circuits, effectively reduce voltage and power loss, and improve task reliability. In addition, the dual redundant power supply DC / DC circuit uses fewer components, occupies a small board area, has a simple hardware structure, and has good versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of a dual redundant power supply DC / DC circuit with a safety protection function in an embodiment of the present invention;

[0034] Figure 2 for Figure 1 A schematic diagram of the structure of a power supply gating and short circuit prevention subcircuit in a dual redundant power supply DC / DC circuit with safety protection function provided by the illustrated embodiment;

[0035] Figure 3 for Figure 1 The illustrated embodiment is a schematic structural diagram of a DC / DC sub-circuit in a dual redundant power supply DC / DC circuit with a safety protection function. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0037] As described in the above background technology, the existing power supply switching method of the gate diode has a risk of burning out the entire circuit due to a diode short circuit, because the voltage and power loss on the diode are very large.

[0038] In view of the technical problems existing in the power supply switching mode of the existing gate diode, it is urgent to provide a more reliable, efficient and fault-proof dual redundant power supply mode. In addition, with the development of integrated circuits, the different power supply voltages and interface voltages of DSP, FPGA and memory chips require flexibly configurable power supply outputs.

[0039] In order to realize the above-mentioned dual redundant power supply mode with high reliability, high efficiency and the ability to prevent fault propagation, the present invention proposes a dual redundant power supply DC / DC circuit with a safety protection function.

[0040] The present invention provides the following specific embodiments which can be combined with each other. The same or similar concepts or processes may not be described in detail in some embodiments.

[0041] Figure 1 The schematic diagram of the structure of a dual redundant power supply DC / DC circuit with safety protection function in an embodiment of the present invention is shown in FIG. The dual redundant power supply DC / DC circuit provided in an embodiment of the present invention may include: a power supply gating and short circuit prevention subcircuit and a DC / DC subcircuit.

[0042] like Figure 1 In the structure of the dual redundant power supply DC / DC circuit shown, the power supply gating and short circuit prevention subcircuit includes: a field effect transistor gating controller, two power field effect transistors and two fuses.

[0043] like Figure 1 In the circuit structure of the power gating and short-circuit prevention subcircuit, the two power input sensing ports of the field effect transistor gating controller are connected to two voltage sources one by one, such as Figure 1 In 5V1 and 5V2, the two power output sensing ports are connected to the parallel output terminals respectively, such as Figure 1In VOUT1 / VOUT2, the two driving ports are connected to the control ends of the two power field effect tubes one by one, the input ends of the two power field effect tubes are connected to the two voltage sources one by one, the output ends are connected to the above-mentioned parallel output ends through a fuse respectively, and the parallel output ends are connected to the input ends of the DC / D sub-circuit.

[0044] Based on the structure of the dual redundant power supply DC / DC circuit provided by the embodiment of the present invention, the field effect transistor selection controller is specifically responsible for the comparative monitoring of the two power input sensing ports and their corresponding power output sensing ports. For example, by monitoring the voltage difference between the two power input sensing ports and their corresponding power output sensing ports, it is determined to select one of the power field effect transistors and turn off the other power field effect transistor at the same time, thereby realizing the switching of dual redundant power supply.

[0045] It should be noted that the power field effect tube is used in the embodiment of the present invention because of its small on-resistance, small on-voltage drop, and reverse voltage protection characteristics; therefore, the on-resistance can be reduced and the on-voltage drop can be reduced by using the power field effect tube.

[0046] In the specific implementation of the embodiment of the present invention, the specific method of the field effect transistor gating controller to realize dual redundant power supply switching is: monitoring the voltage difference between the two power input sensing ports and their corresponding power output sensing ports, shutting down the power field effect transistor on the input voltage source side lower than the parallel output terminal voltage Vout, and turning on the power field effect transistor on the input voltage source side higher than the parallel output terminal voltage Vout, thereby realizing automatic switching judgment and gating of the dual redundant power supplies.

[0047] In addition, the structure of the power supply gating and anti-short circuit sub-circuit adopted in the embodiment of the present invention also has the function of preventing the input voltage source side from being short-circuited and grounded. Since the input voltage source on one side is smaller than the parallel output terminal voltage Vout, it is disconnected after being turned off, i.e., not grounded.

[0048] Figure 2 for Figure 1 The embodiment shown is a schematic diagram of a power supply gating and short circuit prevention subcircuit in a dual redundant power supply DC / DC circuit with safety protection function. Figure 2 As shown, the connection ports of the field effect transistor gating controller in the embodiment of the present invention include: two power input sensing ports, such as Figure 2 VIN1 and VIN2; two power output sensing ports, such as Figure 2 In VOUT1 and VOUT2; two drive ports, such as Figure 2 GATE1 and GATE2 in the middle; input enable terminals EN1 and EN2 are both grounded.

[0049] like Figure 2In the structure of the power supply gating and short circuit prevention sub-circuit shown, the first voltage source 5V1 is connected to VIN1 and the source S1 and VIN1 of the power field effect tube 1 respectively, the second voltage source 5V2 is connected to VIN2 and the source S2 of the power field effect tube 2 respectively, VOUT1 and VOUT2 are respectively connected to the parallel output terminal Vout, the gate G1 of the power field effect tube 1 is connected to GATE1, the drain D1 is connected to the front end of the fuse 1, the gate G2 of the power field effect tube 2 is connected to GATE2, the drain D2 is connected to the front end of the fuse 2, and the rear ends of the fuse 1 and the fuse 2 are respectively connected to the parallel output terminals.

[0050] exist Figure 2 In the schematic diagram of the power supply gating and short circuit prevention sub-circuit structure shown in FIG. 1 , the specific implementation method of the field effect transistor gating controller for voltage difference monitoring may include:

[0051] The voltage difference between the first voltage source 5V1 and the power output sensing port VOUT1 and the voltage difference between the second voltage source 5V2 and the power output sensing port VOUT2 are monitored respectively.

[0052] Furthermore, in this specific implementation, the method for determining and gating the field effect transistor gating controller may include the following situations:

[0053] Case 1: When the voltage Vout at the parallel output terminal is higher than the first voltage source 5V1 and lower than the second voltage source 5V2, the voltage of GATE2 will be pulled up and the voltage of GATE1 will be pulled down, thereby driving the power field effect transistor 2 to be turned on and the power field effect transistor 1 to be turned off, so that the second voltage source 5V2 is used as the power supply;

[0054] Case 2: When the parallel output voltage Vout is higher than the second voltage source 5V2 and lower than the first voltage source 5V1, the GATE1 voltage will be pulled up and the GATE2 voltage will be pulled down, thereby driving the power field effect transistor 1 to be turned on and the power field effect transistor 2 to be turned off, so that the first voltage source 5V1 is used as the power supply.

[0055] In one implementation of the embodiment of the present invention, the power field effect tube should be an N-channel field effect tube, because the N-channel field effect tube has a small on-resistance and low voltage loss, and can withstand a large reverse voltage. The impedance of the selected N-channel field effect tube is 0.8mΩ to 1.5mΩ when it is turned on, and the maximum voltage drop when it is turned on when the voltage source is 5V and the voltage load is 2A is only 0.003V. The voltage drop of the N-channel field effect tube itself is much lower than the on-voltage drop of the diode voltage selection, so that the use efficiency of the voltage source is improved; in addition, the maximum drain-source voltage of the N-channel field effect tube is 25V, which can ensure that when the source is short-circuited to ground, the field effect tube can withstand the reverse voltage without damage.

[0056] Furthermore, in the structure of the power gating and short-circuit prevention subcircuit designed in the embodiment of the present invention, the function of the field effect transistor gating controller also includes: when the first voltage source 5V1 is short-circuited to the ground, the voltage Vout of the parallel output terminal is higher than the voltage of the first voltage source 5V1, the GATE1 voltage is controlled to be lowered and the field effect transistor 1 is turned off; and when the second voltage source 5V2 is short-circuited to the ground, the voltage Vout of the parallel output terminal is higher than the voltage of the second voltage source 5V2, the GATE2 voltage is controlled to be lowered and the field effect transistor 2 is turned off. It should be noted that since the drain-source voltage tolerance of the field effect transistor is 25V higher than Vout, it will not be broken down and turned on.

[0057] Furthermore, if Figure 1 In the structure of the dual redundant power supply DC / DC circuit shown, each fuse is connected between the drain of the corresponding power field effect tube and the subsequent DC / DC sub-circuit, and its function is to cut off the path to which it is connected for protection when a short circuit occurs between the source and drain of the power field effect tube connected to the fuse due to failure or burning.

[0058] It should be noted that when a short circuit occurs between the source and drain of a power field effect tube, especially when the power field effect tube burns out or breaks down and short circuits occur, and needs to be turned off but the field effect gating controller cannot turn off the power field effect tube, the fuse can cut off the path for protection, thereby achieving short circuit protection for the back end of the circuit and preventing the fault from spreading. Therefore, the dual redundant power supply DC / DC circuit of the embodiment of the present invention is provided with a fuse. When the field effect tube fails or burns out and causes a short circuit, the fuse can cut off the circuit on that side, thereby improving the reliability of the overall circuit.

[0059] In one implementation of the embodiment of the present invention, the DC / DC subcircuit in the dual redundant power supply DC / DC circuit can be configured as an output configurable DC / DC subcircuit, which has multiple output paths, and each output path is provided with a corresponding configuration resistor, and the output voltage of the corresponding output path is configured by the configuration resistor; wherein the output voltage of each output path can be configured to the same voltage value or different voltage values. The output configurable DC / DC subcircuit can be configured with different setting resistors to provide different voltage source outputs according to the voltage requirements of the back-end power chip. Figure 1 As shown, an example with two output paths is shown.

[0060] Figure 3 for Figure 1 The structure diagram of a DC / DC subcircuit in a dual redundant power supply DC / DC circuit with safety protection function provided by the embodiment shown. The DC / DC subcircuit specifically includes two output paths, and the two output paths have two groups of input ports, such as Figure 3 Vin1 and Vin2; two groups of output ports, such as Figure 3 Vout1 and Vout2; two start control ports, such as Figure 3 RUN1 and RUN2; two configuration ports, such as Figure 3 FB1 and FB2; it should be noted that each group of input ports and each group of output ports can be implemented by multiple parallel ports.

[0061] like Figure 3 In the specific structure of the DC / DC sub-circuit, each group of input ports is respectively connected to the parallel output terminals OUT1 / OUT2 of the power supply gating and short-circuit protection sub-circuit, and each group of input ports is respectively connected to two parallel capacitors for decoupling the output voltage Vout of the parallel output terminals and reducing jitter.

[0062] Each group of output ports is connected to three parallel capacitors to ensure stable power supply to the back-end power-consuming chips.

[0063] Each start-up control port is connected to the parallel output terminal of the power supply gating and short-circuit protection sub-circuit through a pull-up resistor, so as to enable the corresponding output path inside the DC / DC sub-circuit.

[0064] Each configuration port is grounded via a configuration resistor, and is used to configure the output voltage of the output path where the configuration port is located by configuring the resistance value of the configuration resistor, that is, to configure the output voltage of the output ports Vout1 and Vout2.

[0065] The dual redundant power supply DC / DC circuit with safety protection function provided by the embodiment of the present invention reasonably designs the structure of the power supply gating and anti-short circuit sub-circuit, so that the field effect tube gating controller in the sub-circuit can judge to select one of the power field effect tubes and turn off the other power field effect tube at the same time by monitoring the voltage difference between the two power input sensing ports and the corresponding power output sensing ports, so as to realize the switching of dual redundant power supply; in the sub-circuit, the on-resistance is reduced by using the power field effect tube, and the on-voltage drop is reduced; in addition, a fuse is arranged between the drain of the power field effect tube and the rear-stage DC / DC sub-circuit, when a short circuit occurs between the source and drain of the power field effect tube, especially when the power field effect tube is burned or short-circuited and needs to be turned off but the field effect gating controller cannot turn off the power field effect tube, the fuse can cut off the path for protection to avoid the spread of the fault; furthermore, in the circuit, the output configurable DC / DC sub-circuit provides a configurable power output for the back-end power-consuming chip. The dual redundant power supply DC / DC circuit provided in the embodiment of the present invention can not only judge, select and quickly switch two external power supplies, and has short-circuit protection capability, but also can flexibly configure the output power supply according to the back-end power-consuming chip, thereby realizing single-board dual redundant power supply, reducing the use of additional circuits, effectively reducing voltage and power losses, and improving mission reliability.

[0066] The specific implementation of the dual redundant power supply DC / DC circuit with safety protection function provided by the embodiment of the present invention is described below through a specific implementation example.

[0067] Reference Figures 1 to 3 As shown, the dual redundant power supply DC / DC circuit provided in this specific implementation example includes two parts: a power supply gating and short circuit prevention sub-circuit and a DC / DC sub-circuit.

[0068] 1. Functions of power gating and short circuit prevention sub-circuit and related electrical structures:

[0069] like Figure 1 and Figure 2 As shown, the power gating and short-circuit protection sub-circuit is the front-end circuit of the DC / DC sub-circuit, including a field effect transistor gating controller, two power field effect transistors, and two fuses; wherein the field effect transistor gating controller is, for example, LTC4370IMS#PBF, the power field effect transistor is, for example, CSD18501Q5A, and the fuse is, for example, R253 003.

[0070] In this specific embodiment, the field effect transistor gate controller has the following connection ports: two power input sensing ports, such as Figure 2 VIN1 and VIN2; two power output sensing ports, such as Figure 2 OUT1 and OUT2; two drive ports, such as Figure 2 Middle GATE1 and GATE2; input enable terminals EN1 and EN2.

[0071] EN1 and EN2 are both grounded, enabling the monitoring and control functions on both sides of the field effect tube gating controller at the same time; VIN1 is connected in parallel with the source S1 of the power field effect tube 1 and the external 5V input voltage source 5V1; VIN2 is connected in parallel with the source S2 of the field power effect tube 2 and the external 5V input voltage source 5V2; GATE1 and GATE2 are connected to the gates G1 and G2 of the two power field effect tubes in a one-to-one correspondence; the drain D1 of the power field effect tube 1 is connected to the front end of the fuse 1, and the rear end of the fuse 1 is connected in parallel with OUT1 and OUT2; the drain D2 of the power field effect tube 2 is connected to the front end of the fuse 2, and the rear end of the fuse 2 is connected in parallel with OUT1 and OUT2.

[0072] The FET gating controller circuit monitors the input 5V1, 5V2, and the parallel output voltage Vout of VOUT1 and OUT2 respectively. When Vout is higher than 5V1 and lower than 5V2, the controller will pull up the GATE2 voltage and lower the GATE1 voltage, thus driving the power FET 2 and turning off the power FET 1, so that 5V2 is used as the power supply, and vice versa, 5V1 is used as the power supply, thus realizing the judgment and gating between the dual redundant power supplies. When one of the power FETs is turned on, since the impedance of the power FET is only 0.8 to 1.5mΩ when it is turned on, the voltage drop when it is turned on is only 0.003V at most when the general single-board 5V power supply load is 2A, which greatly reduces the conduction voltage drop loss and improves efficiency.

[0073] When the 5V1 power supply is short-circuited to the ground, Vout is higher than the voltage at the 5V1 terminal, and the controller will pull down the GATE1 voltage to turn off the power field effect tube 1. Since the drain-source voltage tolerance of the power field effect tube is 25V higher than Vout, it will not be broken down and turned on. The circuit works in the same way when the 5V2 power supply is short-circuited to the ground, thus realizing the protection of the ground short circuit on the two voltage input sides.

[0074] When one side of the FET is aged or broken down, the FET gating controller needs to turn off the power FET but cannot turn it off, and a short circuit occurs at the rear end Vout, the presence of the fuse can cut off the side path, ensuring the protection of the rear end load from a ground short circuit.

[0075] 2. DC / DC sub-circuit:

[0076] like Figure 3 As shown, the DC / DC sub-circuit adopts a dual-output configurable DC / DC module circuit, such as LTM4616IV#PBF. The dual-output configurable DC / DC module circuit has the following link ports:

[0077] a, two groups of input ports, such as Figure 3 In Vin1 and Vin2, the two sets of input ports are connected to the parallel output terminals of the power selection and short-circuit protection sub-circuit to obtain a 5V power input with double redundancy; in addition, Vin1 and Vin2 terminals are respectively connected to a 10uF and a 1uF capacitor in parallel, totaling 11uF, which can decouple the output voltage of Vout and reduce jitter.

[0078] b, two groups of output ports, such as Figure 3 In the middle, Vout1 and Vout2 are connected to three 10uF capacitors in parallel respectively to ensure the stability of power supply to the back-end power-consuming chips.

[0079] c, two start control ports, such as Figure 3 In RUN1 and RUN2, RUN1 and RUN2 are connected to the parallel output end of the power supply enable and short-circuit protection circuit through a 4.7K pull-up resistor respectively to enable the two output paths inside the DC / DC.

[0080] d, two configuration ports, such as Figure 3 In FB1 and FB2, the DC / DC sub-circuit configures the resistance values ​​of the corresponding configuration resistors (R36, R39) by configuring ports FB1 and FB2, thereby configuring the output port voltages Vout1 and Vout2. The relationship between the configuration resistor size and the output voltage in each output path is shown in Table 1, realizing dual-channel independently configurable output power supplies to meet the voltage requirements of different power-consuming chips.

[0081] Table 1 Relationship between resistance and output voltage

[0082] Vout1 / Vout2 0.596V 1.2V 1.5V 1.8V 2.5V 3.3V <![CDATA[R FB ]]> open circuit 10K 6.65K 4.87K 3.09K 2.21K

[0083] For example, by configuring the resistance values ​​of the above-mentioned configuration resistors (R36, R39), two identical or two arbitrary power supply outputs in 3.3V, 2.5V, 1.8V, 1.5V, and 1.2V gears can be achieved to adapt to the different power supply voltages and interface power supply voltages of the current DSP, FPGA, and memory chips.

[0084] The dual redundant power supply DC / DC circuit with safety protection function provided in this specific embodiment uses fewer components, occupies a small board area, has a simple hardware structure, has the characteristics of uninterrupted dual redundant power supply switching, small conduction voltage drop, short circuit protection, and configurable output voltage, and has high reliability and good versatility.

[0085] By adopting the dual redundant power supply DC / DC circuit provided in this specific embodiment, when two power supplies are provided inside the onboard computer, the single board can select and quickly switch the power supplies to achieve dual redundant power supply; take measures to prevent overcurrent and short circuit to avoid the spread of faults; provide a flexibly configurable power supply voltage for the back-end chip, reduce the use of additional circuits, effectively reduce voltage and power losses, and improve mission reliability.

[0086] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A dual redundant power supply DC / DC circuit with safety protection function, characterized in that: include: Power gating and short circuit prevention subcircuit and DC / DC subcircuit; The power supply gating and short circuit prevention subcircuit comprises: a field effect tube gating controller, two power field effect tubes and two fuses; Wherein, the two power input sensing ports of the field effect tube gating controller are connected to two voltage sources one by one, the two power output sensing ports of the field effect tube gating controller are connected to the parallel output ends respectively, the two driving ports of the field effect tube gating controller are connected to the control ends of the two power field effect tubes one by one, the input ends of the two power field effect tubes are connected to the two voltage sources one by one, the output ends of the two power field effect tubes are connected to the parallel output ends respectively through a fuse, and the parallel output ends are connected to the input ends of the DC / DC sub-circuit; The field effect transistor gating controller is used to monitor the voltage difference between the two power input sensing ports and their corresponding power output sensing ports, determine to select one of the power field effect transistors and simultaneously turn off the other power field effect transistor, so as to realize the switching of dual redundant power supply; The field effect transistor gating controller is specifically used to monitor the voltage difference between the two power input sensing ports and their corresponding power output sensing ports, shut down the power field effect transistor on the input voltage source side that is lower than the parallel output terminal voltage Vout, and turn on the power field effect transistor on the input voltage source side that is higher than the parallel output terminal voltage Vout, thereby realizing automatic switching judgment and gating of dual redundant power supplies.

2. The dual redundant power supply DC / DC circuit with safety protection function according to claim 1, characterized in that: The two voltage sources include a first voltage source 5V1 and a second voltage source 5V2, and the connection ports of the field effect transistor gate controller include: two power input sensing ports VIN1 and VIN2; two power output sensing ports VOUT1 and VOUT2; two drive ports GATE1 and GATE2; two input enable ports EN1 and EN2 are both grounded; Among them, the first voltage source 5V1 is respectively connected to the power input sensing port VIN1 and the source S1 of the power field effect tube 1, the second voltage source 5V2 is respectively connected to the power input sensing port VIN2 and the source S2 of the power field effect tube 2, the two power output sensing ports VOUT1 and VOUT2 are respectively connected to the parallel output terminals, the gate G1 of the power field effect tube 1 is connected to the driving port GATE1, the drain D1 of the power field effect tube 1 is connected to the front end of the fuse 1, the gate G2 of the power field effect tube 2 is connected to the driving port GATE2, the drain D2 of the power field effect tube 2 is connected to the front end of the fuse 2, and the rear ends of the fuse 1 and the fuse 2 are respectively connected to the parallel output terminals.

3. The dual redundant power supply DC / DC circuit with safety protection function according to claim 2, characterized in that: The field effect tube gating controller performs pressure difference monitoring, including: respectively monitoring the voltage difference between the first voltage source 5V1 and the power output sensing port VOUT1, and the voltage difference between the second voltage source 5V2 and the power output sensing port VOUT2; The field effect tube gating controller performs judgment and gating, including: When the voltage Vout at the parallel output terminal is higher than the first voltage source 5V1 and lower than the second voltage source 5V2, the voltage of the driving port GATE2 is pulled up and the voltage of the driving port GATE1 is pulled down, thereby driving the power field effect transistor 2 to be turned on and the power field effect transistor 1 to be turned off, so that the second voltage source 5V2 is used as the power supply; When the parallel output terminal voltage Vout is higher than the second voltage source 5V2 and lower than the first voltage source 5V1, the voltage of the driving port GATE1 will be pulled up and the voltage of the driving port GATE2 will be pulled down, thereby driving the power field effect transistor 1 to be turned on and the power field effect transistor 2 to be turned off, so that the first voltage source 5V1 is used as the power supply.

4. The dual redundant power supply DC / DC circuit with safety protection function according to claim 3, characterized in that: The power field effect tube adopts an N-channel field effect tube, and the impedance of the N-channel field effect tube when it is turned on is 0.8mΩ to 1.5mΩ. The maximum voltage drop when it is turned on when the voltage source is 5V and the load is 2A is 0.003V, and the maximum drain-source voltage is 25V.

5. The dual redundant power supply DC / DC circuit with safety protection function according to claim 4, characterized in that: The field effect transistor gating controller is also used for controlling the voltage of the driving port GATE1 to be pulled down and the power field effect transistor 1 to be turned off when the voltage Vout of the parallel output terminal is higher than the voltage of the first voltage source 5V1 when the first voltage source 5V1 is short-circuited to the ground; When the second voltage source 5V2 is short-circuited to the ground, the voltage Vout of the parallel output terminal is higher than the voltage of the second voltage source 5V2, so the voltage of the driving port GATE2 is controlled to be pulled down and the power field effect tube 2 is turned off.

6. The dual redundant power supply DC / DC circuit with safety protection function according to claim 5, characterized in that: Each of the fuses is connected between the drain of the corresponding power field effect tube and the subsequent DC / DC sub-circuit, and is used to cut off the path to which it is connected for protection when a short circuit occurs between the source and drain of the power field effect tube connected to the fuse.

7. The dual redundant power supply DC / DC circuit with safety protection function according to claim 6, characterized in that: The DC / DC subcircuit is configured as an output configurable DC / DC subcircuit, having multiple output paths and each output path is provided with a corresponding configuration resistor, and the output voltage of the corresponding output path is configured by the configuration resistor; wherein the output voltage of each output path is configured to be the same voltage value or different voltage values.

8. The dual redundant power supply DC / DC circuit with safety protection function according to claim 7, characterized in that: The DC / DC subcircuit specifically includes two output paths, the two output paths having two groups of input ports Vin1 and Vin2; two groups of output ports Vout1 and Vout2; two start control ports RUN1 and RUN2; and two configuration ports FB1 and FB2; Wherein, each group of input ports is respectively connected to the parallel output terminals of the power supply gating and short circuit prevention sub-circuit, and each group of input ports is respectively connected to two parallel capacitors, for decoupling the parallel output terminal voltage Vout and reducing jitter; Each group of output ports is connected to three parallel capacitors to ensure the stability of power supply to the back-end power-consuming chips; Each start control port is connected to the parallel output terminal of the power supply gating and short circuit prevention sub-circuit through a pull-up resistor, so as to enable the corresponding output path inside the DC / DC sub-circuit; Each configuration port is grounded via a configuration resistor, and is used to configure the output voltage of the output path where the configuration port is located by configuring the resistance value of the configuration resistor.

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