A radiation-hardened bandgap reference circuit

Abstract

The application provides a kind of anti-radiation band gap reference circuit, including starting module, band gap reference core module and radiation compensation module, starting module generates starting current, prevent band gap reference module in zero state;Band gap reference core module, generate small reference voltage and PTAP current with temperature variation;Radiation compensation module, automatically compensate the change of reference voltage caused by radiation, so that the total dose ability is strong.When the overall circuit is in radiation environment, the base current of triode will increase, resulting in reference voltage V REF rise, cause other modules can not work normally.The application increases radiation compensation module, when the base current of Q2, Q3 increases due to radiation, resulting in the value of V REF increase, through the adjustment of radiation compensation module, V REF restore normal value.Radiation compensation module can be divided into fine adjustment and coarse adjustment, when V REF little change, radiation compensation module uses fine adjustment function, when V REF change, use coarse adjustment function, make V REF restore to original value.

Description

Technical Field

[0001] This invention relates to the field of electrical components technology, and more specifically to a radiation-resistant bandgap reference circuit. Background Technology

[0002] Because the reference voltage generated by a bandgap reference circuit is minimally affected by power supply voltage and temperature, it is widely used in various analog circuits, such as LDOs and DC-DC power management chips. With the development of the aerospace industry, the stability of aerospace equipment operating in radiation environments has become even more critical. This places higher demands on bandgap reference modules, requiring them not only to have a stable output voltage but also to ensure that their output characteristics do not change with radiation dose.

[0003] In a radiated environment, the threshold voltage of MOS devices degrades, leakage current increases, and the gain β of transistor devices decreases. For MOS devices, the total dose immunity is typically improved through layout design and material optimization, such as gate-around-the-ring transistors and dual-guard-ring structures. However, radiation still affects the characteristics of transistors, causing changes in the output voltage of the bandgap reference module.

[0004] Commonly used hardening methods for radiation-hardened reference circuits are too complex, and the hardened circuit is highly susceptible to damage, which may introduce new problems and cause instability in the reference voltage, such as... Figure 1 As shown, in addition to the problems mentioned above, it also results in a large layout area and high power consumption.

[0005] Therefore, a radiation-resistant bandgap reference circuit with high radiation dose resistance and low power consumption is needed. Summary of the Invention

[0006] This invention addresses the problems of radiation resistance in bandgap reference circuits and the instability of reference voltage, large layout area, and high power consumption caused by hardened circuits. It provides a radiation-resistant bandgap reference circuit, comprising a startup module, a bandgap reference core module, and a radiation compensation module. The startup module generates a startup current, providing a continuous current to the bandgap reference core module during circuit startup to prevent it from being in a zero-state. Upon power-up, the voltage across R7 increases, causing M5 to shut down, at which point the startup module's operation ends, and the bandgap reference core module operates normally. When the entire circuit is exposed to radiation, the base current of the transistor increases, causing the reference voltage V to rise. REF The increase in voltage causes other modules to malfunction. This invention adds a radiation compensation module; when the base currents of Q2 and Q3 increase due to radiation, causing V... REF When the value increases, V is adjusted by the radiation compensation module. REF Return to normal value. The radiation compensation module can be divided into fine-tuning and coarse-tuning. When V REF When the changes are minor, the radiation compensation module uses a fine-tuning function; when VREF When there are large changes, use the coarse adjustment function to restore the original value.

[0007] This invention provides a radiation-resistant bandgap reference circuit, comprising a bandgap reference core module and a startup module and a radiation compensation module respectively connected to the bandgap reference core module; The startup module generates a startup current and outputs it to the bandgap reference module when the bandgap reference circuit starts up. The core module of the bandgap reference generates a reference voltage V. REF The radiation compensation module automatically compensates for the reference voltage V caused by radiation. REF Change; The core module of the bandgap reference includes NPN transistors Q2, Q3, Q4, M6, M7, and M8, resistors R2, R6, R7, and R11. Resistor R2 is connected between the bases of transistors Q2 and Q3. The source of transistor M6 is connected to VCC, and its gate and drain are connected to the gate of transistor M7 and the collector of transistor Q2, respectively. The source of transistor M7 is connected to VCC, and its drain is connected to the gate of transistor M8 and the collector of transistor Q3, respectively. The emitter of transistor Q2 is grounded, and the emitter of transistor Q3 is connected to resistor R11 and then grounded. The source of transistor M8 is connected to VCC, and its drain is connected to resistors R6 and R7 in sequence. The lower end of resistor R7 is connected to the collector of transistor Q4. The base and collector of transistor Q4 are both connected to the base of transistor Q2, and the emitter of transistor Q4 is grounded. The upper end of resistor R6 outputs V. REF The starting current is input at the upper end of resistor R7; The radiation compensation module includes a fine-tuning compensation module and a coarse-tuning compensation module. Both modules include an inverter, a resistor, and a PMOS transistor. The inverter threshold voltage of the fine-tuning compensation module is lower than that of the coarse-tuning compensation module, but both are greater than V when there is no radiation. REF In the fine-tuning compensation module, two inverters connected in series form a group; When there is no radiation, the inverter group of the fine-tuning compensation module outputs a low level, causing the resistor of the fine-tuning compensation module to be connected in parallel with resistor R2, and the inverter group of the coarse-tuning compensation module outputs a high level, and the PMOS transistor is not turned on. When the total dose of radiation causes an increase in the base currents of tubes Q2 and Q3, V REF When the voltage increases, the inverter section of the fine-tuning compensation module is not conducting. The resistance in parallel with resistor R2 is reduced, and the resistance between transistors Q2 and Q3 is increased to lower V. REF ; When the total radiation dose causes the base currents of tubes Q2 and Q3 to continue increasing until they exceed the adjustment range of the fine-tuning compensation module, the inverter of the coarse-tuning compensation module turns on, connecting the resistor of the coarse-tuning compensation module in parallel with resistor R7 to reduce the resistance value at the lower end of resistor R6 and lower V. REF .

[0008] The radiation-resistant bandgap reference circuit described in this invention, as a preferred embodiment, ; Among them, V T Let be the thermoelectric constant, n be the ratio of the number of parallel tubes Q3 to the number of parallel tubes Q2, and ln be the logarithmic sign. B I is the current flowing into resistor R2. BF V represents the increase in base current of tubes Q2 and Q3 under radiation conditions. BE4 This is the voltage between the base and emitter of transistor Q4.

[0009] In a preferred embodiment of the radiation-resistant bandgap reference circuit described in this invention, the collector current I of transistor Q3... PTPA for: ; The core module of the bandgap reference also includes PMOS transistor M9 and capacitor C1; The lower end of capacitor C1 and the gate of transistor M9 are connected to the drain of transistor M7. The upper end of capacitor C1 is connected to VCC. The source of transistor M9 is connected to VCC, and the drain provides current I. PTPA ; Reference voltage V REF The inverters connected to the fine-tuning compensation module and the coarse-tuning compensation module respectively have collector currents of I and drain currents of I0 and M9 respectively. PTPA .

[0010] In the radiation-resistant bandgap reference circuit described in this invention, as a preferred embodiment, the resistance values ​​of resistors R6 and R7 are both greater than the resistance values ​​of resistors R2 and R11.

[0011] The radiation-resistant bandgap reference circuit of the present invention, in a preferred embodiment, includes a fine-tuning compensation module comprising a first fine-tuning compensation module, a second fine-tuning compensation module, and a third fine-tuning compensation module connected in parallel. The first fine-tuning compensation module includes inverters INV4 and INV7 with hysteresis function, resistor R3, and PMOS transistor M10; the upper end of inverter INV4 is connected to the reference voltage V. REF The lower end is connected in sequence to inverter INV7, gate of transistor M10, drain of transistor M10 connected between resistor R2 and base of transistor Q3, source connected to one end of resistor R3, and the other end of resistor R3 connected between resistor R2 and base of transistor Q2. The second fine-tuning compensation module includes inverters INV5 and INV8 with hysteresis, resistor R4, and PMOS transistor M11; the upper end of inverter INV5 is connected to the reference voltage V. REFThe lower end is connected in sequence to inverter INV8, gate of transistor M11, drain of transistor M11 connected between resistor R2 and base of transistor Q3, source connected to one end of resistor R4, and the other end of resistor R4 connected between resistor R2 and base of transistor Q2. The third fine-tuning compensation module includes inverters INV6 and INV9 with hysteresis, resistor R5, and PMOS transistor M12; the upper end of inverter INV6 is connected to the reference voltage V. REF The lower end is connected in sequence to inverter INV9, gate of transistor M12, drain of transistor M12 connected between resistor R2 and base of transistor Q3, source connected to one end of resistor R5, and the other end of resistor R5 connected between resistor R2 and base of transistor Q2. The threshold voltages of inverters INV4, INV5, and INV6 increase sequentially, while the threshold voltages of inverters INV7, INV8, and INV9 are the same.

[0012] The radiation-resistant bandgap reference circuit of the present invention, in a preferred embodiment, includes a coarse adjustment compensation module comprising a first coarse adjustment compensation submodule, a second coarse adjustment compensation submodule, and a third coarse adjustment compensation submodule connected in parallel. The first coarse adjustment compensation submodule includes an inverter INV1 with hysteresis function, a resistor R10, and a PMOS transistor M15. The upper end of the inverter INV1 is connected to the reference voltage V. REF The lower end is connected to the gate of transistor M15. The drain of transistor M15 is connected between resistor R7 and collector of transistor Q4. The source is connected to one end of resistor R10. The other end of resistor R10 is connected between resistor R6 and resistor R7. The second coarse adjustment compensation submodule includes an inverter INV2 with hysteresis function, a resistor R9, and a PMOS transistor M14. The upper end of the inverter INV2 is connected to the reference voltage V. REF The lower end is connected to the gate of transistor M14. The drain of transistor M14 is connected between resistor R7 and the collector of transistor Q4. The source is connected to one end of resistor R9. The other end of resistor R9 is connected between resistor R6 and resistor R7. The third coarse adjustment compensation submodule includes an inverter INV3 with hysteresis function, a resistor R8, and a PMOS transistor M13. The upper end of the inverter INV3 is connected to the reference voltage V. REF The lower end is connected to the gate of transistor M13. The drain of transistor M13 is connected between resistor R7 and collector of transistor Q4. The source is connected to one end of resistor R8. The other end of resistor R8 is connected between resistor R6 and resistor R7. The threshold voltages of inverters INV1, INV2, and INV3 increase sequentially.

[0013] In a preferred embodiment of the radiation-resistant bandgap reference circuit described in this invention, the threshold voltages of inverters INV4, INV5, and INV6 are all lower than the threshold voltages of inverters INV1, INV2, and INV3, and are all greater than V when there is no radiation. REF ; The threshold voltage increments of inverters INV4, INV5, and INV6 are all smaller than the threshold voltage increments of inverters INV1, INV2, and INV3. Adjustment V of the fine-tuning compensation module REF The capability is on the order of nA, and the coarse adjustment compensation module adjusts V. REF Its capabilities exceed those of the fine-tuning compensation module; The resistance values ​​of resistors R6 and R7 are both greater than the resistance values ​​of resistors R3, R4, and R5.

[0014] In the radiation-resistant bandgap reference circuit described in this invention, as a preferred embodiment, the number of both the fine-tuning compensation submodule and the coarse-tuning compensation submodule can be greater than or equal to 3.

[0015] The radiation-resistant bandgap reference circuit described in this invention, as a preferred embodiment, when the total dose effect causes V REF When the voltage rises to a level greater than the threshold voltage of inverter INV4 but less than the threshold voltages of inverters INV5 and INV6, the output voltage of inverter INV7 becomes high, transistor M10 is not conducting, resistor R2 is connected in parallel only with resistors R4 and R5, and the resistance between transistors Q2 and Q3 increases. REF Decrease; as the total dose continues to increase, V REF It rises again, when V REF When the voltage is greater than the threshold voltage of inverter INV5 but less than the threshold voltage of inverter INV6, the output of inverter INV8 also becomes high, transistor M11 is not conducting, and resistors R2 and R5 are connected in parallel. REF Decrease; as the total dose continues to increase, V REF It rises again, when V REF When the voltage exceeds the threshold voltage of inverter INV6, the output of inverter INV9 becomes high, transistor M12 is not conducting, resistor R2 is connected in parallel without resistance, and V REF reduce; When the total dose effect leads to V REF When the voltage rises and exceeds the threshold voltage of inverter INV1, transistor M15 turns on, resistors R7 and R10 are connected in parallel, the resistance at the lower end of resistor R6 decreases, and V... REF Voltage decreases; as the total dose increases, V REF Continue to increase, when V REFWhen the voltage exceeds the threshold voltage of inverter INV2, transistor M14 conducts, resistors R9, R10, and R7 are connected in parallel, and the resistance value at the lower end of resistor R6 continues to decrease. REF The voltage decreased again; as the total dose increased, V REF Increase again, when V REF When the voltage exceeds the threshold voltage of inverter INV3, transistor M13 conducts, and resistors R8, R9, R10, and R7 are connected in parallel. The resistance value at the lower end of resistor R6 continues to decrease. REF The voltage dropped again.

[0016] The radiation-resistant bandgap reference circuit of the present invention, in a preferred embodiment, includes a startup module comprising PMOS transistors M1, M2, M3, M4, and M5, a resistor R1, and an NPN transistor Q1. The sources of transistors M1, M2, and M3 are all connected to VCC. The gates of transistors M1 and M2 are connected, and then connected to the drains of transistors M1 and M3. The drain of transistor M1 is connected to ground via resistor R1. The drain of transistor M2 outputs a bias current I. bias The drain of transistor M3 is connected to the drain of transistor M4. The drain of M4 is connected to the gate of transistor M5. The source of transistor M4 is connected to the collector and base of transistor Q1. The emitter of transistor Q1 is grounded. The drain of transistor M5 is connected to VCC, and the source is connected to the upper end of resistor R7 in the bandgap reference core module. When the bandgap reference circuit is powered on, transistor M3 replicates the current generated by transistor M1 and resistor R1 and outputs it to transistors M4 and Q1, causing transistor M5 to conduct. The source current of transistor M5 flows into the upper end of resistor R7 to prevent the bandgap reference core module from being in a zero state. When the bandgap reference core module generates a reference voltage, the voltage at the upper end of resistor R7 increases, causing transistor M5 to turn off, and the module operation is completed.

[0017] The present invention has the following advantages: This invention provides a bandgap reference circuit with a small radiation-resistant structural layout area and high total radiation dose resistance. It consists of a startup module, a bandgap reference core module, and a radiation compensation module. The startup module generates a startup current to prevent the bandgap reference module from being in a zero state. The bandgap reference core module generates a reference voltage and PTAP current that change little with temperature. The radiation compensation module uses an inverter group with hysteresis function to fine-tune and coarsely adjust the reference voltage, automatically compensating for changes in the reference voltage caused by radiation, thus making it highly resistant to total radiation dose. Attached Figure Description

[0018] Figure 1 The circuit diagram for an existing radiation-resistant bandgap reference circuit; Figure 2 A circuit block diagram of a radiation-resistant bandgap reference circuit; Figure 3 A circuit diagram of a radiation-resistant bandgap reference circuit; Figure 4 The total dose and V of a radiation-resistant bandgap reference circuit REF A schematic diagram showing the relationship between voltage changes. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example 1

[0020] A radiation-resistant bandgap reference circuit includes a startup module, a bandgap reference core module, and a radiation compensation module. Figure 2 This is a circuit block diagram of the present invention. Figure 3 This is a specific circuit of the present invention.

[0021] The startup module generates a startup current to prevent the bandgap reference module from being in a zero state; the bandgap reference core module generates a reference voltage and PTAP current that change little with temperature; the radiation compensation module automatically compensates for changes in the reference voltage caused by radiation, resulting in strong resistance to total dose.

[0022] The startup module generates a startup current, providing a continuous current to the bandgap reference core module during circuit startup to prevent it from being in a zero-state. As power-on completes, the voltage across R7 increases, causing M5 to shut down, at which point the startup module's operation ends. The bandgap reference core module then operates normally.

[0023] When the entire circuit is exposed to radiation, the base current of the transistor will increase, causing the reference voltage V to rise. REF The increase in voltage causes other modules to malfunction. This invention adds a radiation compensation module; when the base currents of Q2 and Q3 increase due to radiation, causing V... REF When the value increases, V is adjusted by the radiation compensation module. REF Return to normal value. The radiation compensation module can be divided into fine-tuning and coarse-tuning. When V REF When the changes are minor, the radiation compensation module uses a fine-tuning function; when V REF When the changes are large, the coarse adjustment function is used to restore the base current of Q2 and Q3 to their original values.

[0024] The circuit diagram of this invention is as follows: Figure 3 As shown, this invention provides a low-power bandgap reference circuit with high total radiation dose resistance. It consists of a startup module, a bandgap reference core module, and a radiation compensation module. Figure 3As shown, when the circuit is powered on, M1 and R1 generate a current, M3 replicates this current, and this current flows into M4 and Q1, generating a voltage at the drain and gate of M4, causing M5 to conduct. The source current of M5 flows into R7 of the bandgap reference core module to prevent the bandgap reference from being in a zero state. When the bandgap reference core module generates a reference voltage, the voltage at the upper end of R7 increases, causing M5 to turn off, and the startup module completes its operation.

[0025] In the core module of the bandgap reference, Q2, Q3, R2, and R11 generate a positive temperature coefficient current, i.e., the PTAT current, and the collector current I of transistor Q3. PTPA It can be derived from the following formula: (1) Among them, V T Let I be the thermoelectric constant, a constant; n is the ratio of Q2 to Q3 in transistors; ln is the logarithmic sign; I B The current flowing into R2 is due to the fact that M7 replicates the current of M6. To ensure the accuracy of the current replicated by M7, transistor M8 is added, with its gate connected to the drain of M7. Since M6, M7, and M8 are all the same type of MOSFET, the source, drain, and gate voltages of M6 and M7 are almost equal. Therefore, M8 replicates the current of M7, and the drain current of M8 is also a positive temperature coefficient current. Thus, the reference voltage can be obtained from the following formula: (2) V BE4 This is the voltage between the base and emitter of transistor Q4; When the total radiation dose causes an increase in the base current of the transistor, the current flowing through R6 and R7 increases, leading to V REF By increasing the voltage, we obtain the formula for the reference voltage under radiation conditions. (3) I BF I represents the increase in base current of the transistor under radiation conditions, which increases with the increase of the total radiation dose. BF It also gradually increased; Therefore, it can be seen from the above formula that V can be adjusted by changing the ratio of resistor R2 to R11. REF Keeping it unchanged, you can also change the values ​​of R6 and R7 to make V REF It remains unchanged.

[0026] In this embodiment, Q2 and Q3 are transistors of the same type, with their emitter areas in a certain ratio, typically 1:8. The sum of the resistances of R6 and R7 is several hundred kΩ. R2, R3, R4, R5, and R11 are all tens of kΩ.

[0027] When the total radiation dose increases, I BFIncrease, leading to V REF Also increased. Among them, INV1~INV9 are inverters with different thresholds and hysteresis functions.

[0028] R8, R9, R10, M13, M14, M15, and INV1~INV3 constitute coarse adjustment compensation, while R3, R4, R5, and M10~M12 constitute fine adjustment compensation. When V REF When the change caused by radiation is small, the fine-tuning operation is activated, turning off M10~M12. This increases the resistance between the bases of Q2 and Q3, so V... REF Decrease. Depending on the radiation level, tubes M10 through M12 are closed sequentially. When V REF When the changes caused by radiation are large, and the fine adjustment is ineffective, the coarse adjustment begins to work, turning on M13~M15 and causing V to... REF As the radiation level decreases, tubes M13 through M15 sequentially conduct. The resistances of R8, R9, and R10 are several hundred kΩ.

[0029] The fine-tuning function adjusts the current flowing through the drain of M8, in the order of nA. The resistance values ​​of R3, R4, and R5 can be set to determine the overall dose rejection capability. The fine-tuning range is determined by the inverter's flip-flop voltage, which can be a few millivolts. The inverter's hysteresis range is typically tens of millivolts to prevent the bandgap reference from oscillating at the flip-flop point.

[0030] The coarse adjustment is used when the total dose exceeds the adjustment capability of the fine-tuning circuit. REF As the total dose continues to increase, when it reaches a certain value and exceeds the switching voltage of the hysteresis inverter, it causes V to... REF As the voltage decreases, the fine-tuning range is determined by the inverter's flip-flop voltage, which can be set to tens of millivolts. The inverter's hysteresis range is typically tens of millivolts to prevent the bandgap reference from oscillating at the flip-flop point.

[0031] For fine-tuning, the threshold voltages of the inverters, INV4, INV5, and INV6, are gradually increased, in increments of 13mV.

[0032] For coarse adjustment, the threshold voltages of the inverters, INV1, INV2, and INV3, are gradually increased, and can be increased in increments of 67mV.

[0033] The threshold voltage of INV6 is less than that of INV1, while the threshold voltages of the three inverters INV7, INV8, and INV9 are all VCC / 2.

[0034] Fine-tuning working principle: When there is no radiation, V REF The voltage remains constant, and V REFThe voltage is less than the threshold voltage of inverters INV4, INV5, and INV6. At this time, the three inverters output a high level, so the three inverters INV7, INV8, and INV9 output a low level, which makes M10, M11, and M12 conduct. At this time, the resistance value of R2 in equation (2) is R2 connected in parallel with R3, R4, and R5.

[0035] As the amount of radiation increases, V REF Rise, when V REF When the threshold voltage greater than INV4 is less than the threshold voltages of INV5 and INV6, INV4 outputs a low level and INV7 outputs a high level. At this time, M10 is not conducting. In this case, the value of R2 in equation (2) is the parallel connection of R2, R4, and R5. The resistance value increases, and V REF Decrease. As the total dose increases, V REF It will rise further, causing INV5 and INV6 to flip to low level in sequence, and INV8 and INV9 to flip to high level in sequence, causing M11 and M12 to turn off in sequence, ultimately making R2 in the above formula not connected in parallel with any resistor.

[0036] Coarse adjustment working principle: When the circuit is not radiated, V REF The voltage remains constant, and the VREF voltage is less than the threshold voltages of inverters INV1, INV2, and INV3. At this time, the outputs of the three inverters are high, M13, M14, and M5 are not conducting, and R7 in the above equation is not connected in parallel with R8, R9, and R10. As the radiation increases, I in equation (2) BF Increase, leading to V REF Increase, when V REF When the voltage is greater than the threshold voltage of INV1 but less than the threshold voltages of INV2 and INV3, INV1 outputs a low level. At this time, M15 is turned on, and R7 and R10 are connected in parallel. The resistance value of R7 in the above formula decreases, thus making V... REF Decrease. As the total dose increases, V REF The voltage will continue to rise, and INV2 and INV3 will successively flip to low level, causing M14 and M13 to conduct in sequence. The resistance value of R7 will decrease sequentially, resulting in V... REF Voltage drop.

[0037] Figure 4 For total dose and V REF The relationship between voltage changes. In the fine-tuning A phase: as the total dose increases, V REF Gradually increase the dose, with INV4, INV5, and INV6 flipping sequentially. After INV6 flips, as the total dose increases, V... REF When the voltage is increased to the threshold voltage of INV1 in the coarse adjustment section, INV1 flips, as shown. Figure 4 Coarse adjustment area 1, VREF Drop to 1.2V, then start fine-tuning again. The other adjustments work on the same principle.

[0038] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A radiation-resistant bandgap reference circuit, characterized in that: It includes a bandgap reference core module and a startup module and a radiation compensation module respectively connected to the bandgap reference core module; The startup module generates a startup current and outputs it to the bandgap reference core module when the bandgap reference circuit starts up. The bandgap reference core module generates a reference voltage V. REF The radiation compensation module automatically compensates for the reference voltage V caused by radiation. REF Change; The bandgap reference core module includes NPN transistors Q2, Q3, Q4, M6, M7, and M8, resistors R2, R6, R7, and R11. Resistor R2 is connected between the bases of transistors Q2 and Q3. The source of transistor M6 is connected to VCC, and its gate and drain are connected to the gate of transistor M7 and the collector of transistor Q2, respectively. The source of transistor M7 is connected to VCC, and its drain is connected to the gate of transistor M8 and the collector of transistor Q3, respectively. The emitter of transistor Q2 is grounded, and the emitter of transistor Q3 is connected to resistor R11 and then grounded. The source of transistor M8 is connected to VCC, and its drain is connected to resistors R6 and R7 in sequence. The lower end of resistor R7 is connected to the collector of transistor Q4. The base and collector of transistor Q4 are both connected to the base of transistor Q2, and the emitter of transistor Q4 is grounded. The upper end of resistor R6 outputs V. REF The starting current is input to the upper end of resistor R7; The radiation compensation module includes a fine-tuning compensation module and a coarse-tuning compensation module. Both the fine-tuning and coarse-tuning modules include an inverter, a resistor, and a PMOS transistor. The inverter threshold voltage of the fine-tuning compensation module is lower than the inverter threshold voltage of the coarse-tuning compensation module, and both are greater than V when there is no radiation. REF In the fine-tuning compensation module, two inverters connected in series form a group; When there is no radiation, the inverter group of the fine-tuning compensation module outputs a low level, causing the resistor of the fine-tuning compensation module to be connected in parallel with the resistor R2, and the inverter group of the coarse-tuning compensation module outputs a high level, and the PMOS transistor is not turned on. When the total dose of radiation causes an increase in the base currents of tubes Q2 and Q3, V REF When the voltage increases, the inverter group of the fine-tuning compensation module is not turned on, reducing the resistance in parallel with resistor R2 and increasing the resistance between transistors Q2 and Q3 to reduce V. REF ; When the total radiation dose causes the base currents of tubes Q2 and Q3 to continue increasing until they exceed the adjustment range of the fine-tuning compensation module, the inverter of the coarse-tuning compensation module is turned on, connecting the resistor of the coarse-tuning compensation module in parallel with resistor R7, reducing the resistance value at the lower end of resistor R6 and lowering V. REF .

2. The radiation-resistant bandgap reference circuit according to claim 1, characterized in that: ； Among them, V T Let be the thermoelectric constant, n be the ratio of the number of parallel tubes Q3 to the number of parallel tubes Q2, and ln be the logarithmic sign. B I is the current flowing into resistor R2. BF V represents the increase in base current of tubes Q2 and Q3 under radiation conditions. BE4 This is the voltage between the base and emitter of transistor Q4.

3. The radiation-resistant bandgap reference circuit according to claim 2, characterized in that: The collector current I of transistor Q3 PTAT for: ； The bandgap reference core module also includes a PMOS transistor M9 and a capacitor C1; The lower end of capacitor C1 and the gate of transistor M9 are connected to the drain of transistor M7. The upper end of capacitor C1 is connected to VCC. The source of transistor M9 is connected to VCC, and the drain provides current I. PTAT ; Reference voltage V REF The inverters connected to the fine-tuning compensation module and the coarse-tuning compensation module respectively have collector currents of I and drain currents of It for both transistor Q3 and M9. PTAT .

4. The radiation-resistant bandgap reference circuit according to claim 1, characterized in that: The resistance values ​​of resistors R6 and R7 are both greater than the resistance values ​​of resistors R2 and R11.

5. The radiation-resistant bandgap reference circuit according to claim 1, characterized in that: The fine-tuning compensation module includes a first fine-tuning compensation module, a second fine-tuning compensation module and a third fine-tuning compensation module connected in parallel. The first fine-tuning compensation module includes inverters INV4 and INV7 with hysteresis function, resistor R3 and PMOS transistor M10; the upper end of inverter INV4 is connected to the reference voltage V. REF The lower end is connected in sequence to inverter INV7, gate of transistor M10, drain of transistor M10 connected between resistor R2 and base of transistor Q3, source connected to one end of resistor R3, and the other end of resistor R3 connected between resistor R2 and base of transistor Q2. The second fine-tuning compensation module includes inverters INV5 and INV8 with hysteresis, resistor R4, and PMOS transistor M11; the upper end of inverter INV5 is connected to the reference voltage V. REF The lower end is connected in sequence to inverter INV8, gate of transistor M11, drain of transistor M11 connected between resistor R2 and base of transistor Q3, source connected to one end of resistor R4, and the other end of resistor R4 connected between resistor R2 and base of transistor Q2. The third fine-tuning compensation module includes inverters INV6 and INV9 with hysteresis function, resistor R5, and PMOS transistor M12; the upper end of inverter INV6 is connected to the reference voltage V. REF The lower end is connected in sequence to inverter INV9, gate of transistor M12, drain of transistor M12 connected between resistor R2 and base of transistor Q3, source connected to one end of resistor R5, and the other end of resistor R5 connected between resistor R2 and base of transistor Q2. The threshold voltages of inverters INV4, INV5, and INV6 increase sequentially, while the threshold voltages of inverters INV7, INV8, and INV9 are the same.

6. The radiation-resistant bandgap reference circuit according to claim 5, characterized in that: The coarse adjustment compensation module includes a first coarse adjustment compensation submodule, a second coarse adjustment compensation submodule, and a third coarse adjustment compensation submodule connected in parallel; The first coarse adjustment compensation submodule includes an inverter INV1 with hysteresis function, a resistor R10, and a PMOS transistor M15. The upper end of the inverter INV1 is connected to the reference voltage V. REF The lower end is connected to the gate of transistor M15. The drain of transistor M15 is connected between resistor R7 and collector of transistor Q4. The source is connected to one end of resistor R10. The other end of resistor R10 is connected between resistor R6 and resistor R7. The second coarse adjustment compensation submodule includes an inverter INV2 with hysteresis, a resistor R9, and a PMOS transistor M14. The upper end of the inverter INV2 is connected to the reference voltage V. REF The lower end is connected to the gate of transistor M14. The drain of transistor M14 is connected between resistor R7 and the collector of transistor Q4. The source is connected to one end of resistor R9. The other end of resistor R9 is connected between resistor R6 and resistor R7. The third coarse adjustment compensation submodule includes an inverter INV3 with hysteresis function, a resistor R8, and a PMOS transistor M13. The upper end of the inverter INV3 is connected to the reference voltage V. REF The lower end is connected to the gate of transistor M13. The drain of transistor M13 is connected between resistor R7 and collector of transistor Q4. The source is connected to one end of resistor R8. The other end of resistor R8 is connected between resistor R6 and resistor R7. The threshold voltages of inverters INV1, INV2, and INV3 increase sequentially.

7. The radiation-resistant bandgap reference circuit according to claim 6, characterized in that: The threshold voltages of inverters INV4, INV5, and INV6 are all lower than the threshold voltages of inverters INV1, INV2, and INV3, and are all greater than V when there is no radiation. REF ; The threshold voltage increments of inverters INV4, INV5, and INV6 are all smaller than the threshold voltage increments of inverters INV1, INV2, and INV3. The adjustment V of the fine-tuning compensation module REF The capability is on the order of nA, and the coarse adjustment compensation module adjusts V. REF Its capability is greater than that of the fine-tuning compensation module; The resistance values ​​of resistors R6 and R7 are both greater than the resistance values ​​of resistors R3, R4, and R5.

8. A radiation-resistant bandgap reference circuit according to claim 6, characterized in that: The number of both fine-tuning compensation submodules and coarse-tuning compensation submodules can be greater than or equal to 3.

9. A radiation-resistant bandgap reference circuit according to claim 7, characterized in that: When the total dose effect leads to V REF When the voltage rises to a level greater than the threshold voltage of inverter INV4 but less than the threshold voltages of inverters INV5 and INV6, the output voltage of inverter INV7 becomes high, transistor M10 is not conducting, resistor R2 is connected in parallel only with resistors R4 and R5, and the resistance between transistors Q2 and Q3 increases. REF Decrease; as the total dose continues to increase, V REF It rises again, when V REF When the voltage is greater than the threshold voltage of inverter INV5 but less than the threshold voltage of inverter INV6, the output of inverter INV8 also becomes high, transistor M11 is not conducting, and resistors R2 and R5 are connected in parallel. REF Decrease; as the total dose continues to increase, V REF It rises again, when V REF When the voltage exceeds the threshold voltage of inverter INV6, the output of inverter INV9 becomes high, transistor M12 is not conducting, resistor R2 is connected in parallel without resistance, and V REF reduce; When the total dose effect leads to V REF When the voltage rises and exceeds the threshold voltage of inverter INV1, transistor M15 turns on, resistors R7 and R10 are connected in parallel, the resistance at the lower end of resistor R6 decreases, and V... REF Voltage decreases; as the total dose increases, V REF Continue to increase, when V REF When the voltage exceeds the threshold voltage of inverter INV2, transistor M14 conducts, resistors R9, R10, and R7 are connected in parallel, and the resistance value at the lower end of resistor R6 continues to decrease. REF The voltage decreased again; as the total dose increased, V REF Increase again, when V REF When the voltage exceeds the threshold voltage of inverter INV3, transistor M13 conducts, and resistors R8, R9, R10, and R7 are connected in parallel. The resistance value at the lower end of resistor R6 continues to decrease. REF The voltage dropped again.

10. A radiation-resistant bandgap reference circuit according to claim 1, characterized in that: The startup module includes PMOS transistors M1, M2, M3, M4, and M5, resistor R1, and NPN transistor Q1; The sources of transistors M1, M2, and M3 are all connected to VCC. The gates of transistors M1 and M2 are connected, and then connected to the drains of transistors M1 and M3. The drain of transistor M1 is connected to ground via resistor R1. The drain of transistor M2 outputs a bias current I. bias The drain of transistor M3 is connected to the drain of transistor M4. The drain of M4 is connected to the gate of transistor M5. The source of transistor M4 is connected to the collector and base of transistor Q1. The emitter of transistor Q1 is grounded. The drain of transistor M5 is connected to VCC, and the source is connected to the upper end of resistor R7 of the bandgap reference core module. When the bandgap reference circuit is powered on, transistor M3 replicates the current generated by transistor M1 and resistor R1 and outputs it to transistors M4 and Q1, causing transistor M5 to conduct. The source current of transistor M5 flows into the upper end of resistor R7 to prevent the bandgap reference core module from being in a zero state. When the bandgap reference core module generates a reference voltage, the voltage at the upper end of resistor R7 increases, causing transistor M5 to turn off, and the startup module completes its operation.

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