A fast quenching and reset circuit
The SPAD is quenched simultaneously by high-side and low-side quencher circuits, and a rapid reset is achieved using radio frequency transistors, which solves the contradiction between detection efficiency and dead time in lidar ranging, improves detection efficiency and reduces dead time.
Patent Information
- Application Number
- CN202211586119.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-09
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2042-12-09
AI Technical Summary
In long-distance lidar ranging applications, there is a contradiction between the detection efficiency and death time of a single photon avalanche diode (SPAD), which is difficult to simultaneously improve detection efficiency and reduce death time.
The cathode and anode of the avalanche diode are quenched simultaneously by using high-side and low-side quenching sub-circuits, and quickly reset through the high-low-side reset sub-circuits. The radio frequency transistor is used as a high-speed control switch to design and control timing to achieve rapid quenching and reset.
It improves the detection efficiency of SPAD by more than 25%, reduces the dead time by about 16%, and meets the efficient detection needs of lidar ranging applications.
Smart Images
Figure CN116026456B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a fast quenching and reset circuit, which can be used to improve the detection efficiency of single-photon avalanche diodes, and is mainly applied to the fast quenching and reset of single-photon avalanche diodes in lidar ranging applications, belonging to the field of single-photon detection. Background Art
[0002] With the continuous progress of science and technology, people have higher and higher requirements for the sensitivity of detectors in the fields of quantum communication, lidar ranging, three-dimensional imaging, biomedicine, etc. From the original low-light imaging of hundreds of photons to dozens of photons, it has developed to the current ultra-high sensitivity and fast-response detection requirements for single-photon detection. Under this strong demand background, the single-photon avalanche diode (Single Photo Avalanche Diode, SPAD) came into being. Its working principle is that signal photons form signal electrons in the photosensitive area under the action of the photoelectric effect. The signal electrons are accelerated in the reverse-biased high-voltage electric field and then collide with the silicon lattice to generate more electron-hole pairs. The excited electrons will be excited again under the action of the high-voltage electric field to generate more excited electrons. This self-sustaining excitation process can obtain a signal gain of a million times magnitude, forming a detectable avalanche current pulse, thereby realizing single-photon detection. This self-sustaining avalanche process is called Geiger mode.
[0003] The avalanche process of the single-photon avalanche diode will not stop automatically until the generated avalanche current damages the diode. To avoid the unlimited increase of the avalanche current leading to the damage of the avalanche diode, in actual use, it is necessary to quickly reduce the reverse bias voltage of the avalanche diode below the avalanche voltage point after detecting the avalanche current to prevent the continuous generation of avalanche current and protect the avalanche diode. This process of quickly reducing the bias voltage of the avalanche diode is called quenching. After the avalanche current stops, it is necessary to quickly raise the bias voltage of the avalanche diode above the avalanche voltage so that the avalanche diode returns to the normal working state to be ready to respond to the arrival of the next photon signal. This process of quickly preparing the avalanche diode to meet the next generation of avalanche current is called reset.
[0004] The quenching methods of avalanche diodes can be divided into three types: passive quenching, active quenching, and gated quenching. The passive quenching structure is simple, and the quenching principle is as Figure 1 shown. When the avalanche current flows through the current-limiting resistor R L and the current-sensing resistor R S , it will cause the voltage difference across the two resistors to increase, thereby reducing the voltage across the avalanche diode SPAD below the avalanche voltage point to complete quenching. Due to R L and R SThe resistance value is relatively large. Due to reasons such as parasitic capacitance of the resistor and SPAD junction capacitance, both the quenching and reset processes are relatively slow. The single-photon detection period is about in the microsecond order of magnitude, which limits the application of this method in high-speed photon detection.
[0005] The principle of gated quenching is as Figure 2 shown. Compared with passive quenching, a high-speed gated clock signal with AC coupling is introduced at the cathode of the SPAD, controlling the bias voltage across the SPAD to be periodically above and below the avalanche voltage point, so as to periodically receive single-photon signals. Gated quenching is suitable for applications where the arrival time of single photons is known, such as in the field of quantum communication, but not suitable for situations where the arrival time of photons is unknown, such as in the field of lidar ranging applications.
[0006] The principle of active quenching is as Figure 3 shown. The avalanche current becomes a voltage signal after passing through the current-sensing resistor R S and is then shaped by a comparator to output a single-photon pulse signal, and controls the pulse generator to feedback to the anode of the SPAD to control the bias voltage of the SPAD to drop below the avalanche voltage to achieve the purpose of quenching the SPAD. Active quenching has the characteristics of fast quenching speed and short dead time of the SPAD. In lidar ranging applications, the arrival time of photons is unknown, and the SPAD needs to be in a long-term standby state. Once a single-photon signal arrives at the detector, it is required that the SPAD detects as many single photons as possible per unit time, that is, the dead time is required to be as short as possible. Therefore, active quenching is often used to quench the SPAD in lidar ranging applications.
[0007] In long-distance lidar ranging applications, due to the long detection distance, the number of photons reflected from the target to the receiving SPAD is very limited; at the same time, to avoid the influence of stray light, a special spectral narrow-band filter is usually selected to filter out stray light, which will further reduce the number of target-reflected photons that the SPAD can receive. This requires improving the detection efficiency of the SPAD (the probability of a single-photon signal generating an avalanche to form a single-photon electrical pulse signal) to obtain more single-photon pulse data samples. Improving the detection efficiency of the SPAD requires increasing the bias voltage, which means a greater quenching depth is required, which will increase the quenching time and reset time. At the same time, to obtain a larger saturation counting rate, it is necessary to minimize the dead time of the SPAD, and it is required that the quenching circuit of the SPAD has a faster quenching time and reset time. Therefore, improving the detection efficiency by increasing the bias voltage amplitude and reducing the dead time are a pair of contradictions. Summary of the Invention
[0008] (1) Technical problems to be solved
[0009] Aiming at the problem of mutual restriction between the high detection efficiency and low dead time requirements of SPAD in long-distance lidar ranging, a fast quenching and reset circuit is invented, which can improve the detection efficiency of single-photon avalanche diodes.
[0010] (II) Technical solution
[0011] The present invention provides a fast quenching and reset circuit that can improve the detection efficiency of single-photon avalanche diodes.
[0012] A fast quenching and reset circuit, the circuit includes a high-side quenching sub-circuit, a high-side reset sub-circuit, a low-side quenching sub-circuit, a low-side reset sub-circuit, an avalanche diode D1, a sampling resistor R1, and a high-voltage power supply;
[0013] The cathode of the avalanche diode D1 is introduced into the high-side quenching sub-circuit;
[0014] The high-side quenching sub-circuit includes: an AC coupling capacitor C2, protection diodes D2 and D3, current-limiting resistors R4, R5 and R6, push-pull output transistors Q2 and Q3, a pull-up resistor R7, and a level-shifting transistor Q4, and a first quenching power supply; the push-pull output transistor Q2 and the level-shifting transistor Q4 are NPN-type RF transistors, and the push-pull output transistor Q3 is a PNP-type RF transistor;
[0015] The anode of the avalanche diode D1 is introduced into the low-side quenching sub-circuit;
[0016] The low-side quenching sub-circuit includes: an AC coupling capacitor C3, a current-limiting resistor R8, a pull-up resistor R9, a transistor Q5, protection diodes D4 and D5, and a second quenching power supply; the transistor Q5 is a PNP-type RF transistor.
[0017] Further, the cathode of the avalanche diode D1 is introduced into the high-side reset sub-circuit;
[0018] The high-side reset sub-circuit includes: bias resistors R2 and R3, an AC coupling capacitor C1, and a transistor Q1; the transistor Q1 is a PNP-type RF transistor.
[0019] Further, the anode of the avalanche diode D1 is introduced into the low-side reset sub-circuit;
[0020] The low-side reset sub-circuit includes: the avalanche diode D1, the sampling resistor R1, and a transistor Q6; the transistor Q6 is an NPN-type RF transistor.
[0021] Further, the high-side quenching sub-circuit and the low-side quenching sub-circuit are configured to be simultaneously effective and have the same duration, quenching the cathode and anode of the avalanche diode D1 simultaneously; after quenching ends, the low-side reset sub-circuit is immediately set to be effective to reset the anode of the avalanche diode D1; after the low-side reset ends, the high-side reset sub-circuit is immediately set to be effective, and the cathode of the avalanche diode D1 is reset to the high-voltage power supply voltage, and the avalanche diode D1 is ready for the next avalanche excitation.
[0022] Further, in the high-side quenching sub-circuit, the base of the level conversion transistor Q4 is the high-side quenching control port, the emitter is connected to the signal ground, and the collector is connected to the second end of the pull-up resistor R7; the first end of the pull-up resistor R7 is connected to the second end of the current limiting resistor R4, and the first end of the current limiting resistor R4 is connected to the output end of the first quenching power supply; the collector of the push-pull output transistor Q2 is connected to the second end of the current limiting resistor R4, the base is connected to the second end of the current limiting resistor R4, and the emitter is connected to the first end of the current limiting resistor R5; the emitter of the push-pull output transistor Q3 is connected to the second end of the current limiting resistor R6, the base is connected to the second end of the pull-up resistor R7, and the collector is connected to the signal ground; the second end of the current limiting resistor R5 is connected to the first end of the current limiting resistor R6; the anode of the protection diode D2 is connected to the cathode of the protection diode D3, the cathode of the protection diode D2 is connected to the second end of the current limiting resistor R4; the anode of the protection diode D3 is connected to the signal ground; the second end of the AC coupling capacitor C2 is connected to the anode of the protection diode D2; the first end of the AC coupling capacitor C2 is connected to the cathode of the avalanche diode D1.
[0023] Further, in the high-side reset sub-circuit, the first end of the AC coupling capacitor C1 is the control port of the high-side reset sub-circuit; the first end of the AC coupling capacitor C2 is connected to the second end of the bias resistor R2, and the first end of the bias resistor R2 is connected to the emitter of the transistor Q1; the first end of the bias resistor R3 is connected to the first end of the AC coupling capacitor, and the second end of the bias resistor R3 is connected to the collector of the transistor Q1; the emitter of the transistor Q1 is connected to the output end of the high-voltage power supply, the collector is connected to the cathode of the avalanche diode D1, and the base is connected to the second end of the AC coupling capacitor C1.
[0024] Further, in the low-side quenching sub-circuit, the first end of the AC coupling capacitor C3 is the control port of the low-side quenching sub-circuit; the second end of the AC coupling capacitor C3 is connected to the second end of the pull-up resistor R9; the first end of the pull-up resistor R9 is connected to the second end of the current-limiting resistor R8; the first end of the current-limiting resistor R8 is connected to the output end of the second quenching power supply; the base of the transistor Q5 is connected to the second end of the AC coupling capacitor C3, the emitter is connected to the second end of the current-limiting resistor R8, and the collector is connected to the anode of the avalanche diode D1; the anode of the protection diode D4 is connected to the anode of the avalanche diode D1, and the cathode of the protection diode D4 is connected to the second end of the current-limiting resistor R8; the cathode of the protection diode D5 is connected to the anode of the avalanche diode D1, and the anode of the protection diode D5 is connected to the signal ground.
[0025] Further, in the low-side reset sub-circuit, the base of the transistor Q6 is the low-side reset control port; the emitter of the transistor Q6 is connected to the signal ground, and the collector is connected to the anode of the avalanche diode D1; the first end of the sampling resistor R1 is connected to the anode of the avalanche diode D1, and the second end of the sampling resistor R1 is connected to the signal ground.
[0026] According to the above technical solution, a high-side quenching sub-circuit is introduced at the cathode of the SPAD to quench the cathode of the SPAD. The quenching power supply provides a quenching voltage for the high-side quenching sub-circuit. The high-side quenching control port controls the high-side quenching sub-circuit to generate a negative-polarity quenching pulse signal superimposed on the cathode of the SPAD to reduce the cathode voltage of the SPAD; a high-side reset sub-circuit is introduced at the cathode of the SPAD to reset the cathode voltage of the SPAD to the high-voltage power supply voltage and limit the avalanche current of the SPAD after the high-side quenching is completed. The high-side power supply provides a high voltage for the high-side reset sub-circuit. The high-side reset control port controls the high-side reset sub-circuit to provide a bias voltage for the SPAD cathode; the anode of the SPAD uses a current-sensing resistor R1 to convert the avalanche current signal into a voltage signal; a low-side quenching sub-circuit is introduced at the anode of the SPAD to quench the anode of the SPAD. The quenching power supply provides a quenching voltage for the low-side quenching sub-circuit. The low-side quenching control port controls the low-side quenching sub-circuit to generate a positive-polarity quenching pulse signal superimposed on the anode of the SPAD to raise the anode voltage of the SPAD; a low-side reset sub-circuit is introduced at the anode of the SPAD to reset the anode voltage of the SPAD after the low-side quenching is completed. The low-side reset control port controls the low-side reset sub-circuit to reset the cathode voltage of the SPAD to 0V.
[0027] The control timing of the high and low quenching sub-circuits and the high and low reset sub-circuits is as follows: First, the high and low quenching control ports are simultaneously effective and have the same duration to quench the SPAD cathode and anode simultaneously; after quenching, the low-side reset control port is immediately set to be effective to reset the anode of the SPAD; finally, after the low-side reset is completed, the high-side reset control port is immediately set to be effective to reset the SPAD cathode to the high-voltage power supply voltage.
[0028] (III) Beneficial effects
[0029] The present invention uses high and low-side quenching sub-circuits to quench the SPAD simultaneously and uses RF transistors as high-speed control switches, having the following advantages:
[0030] (1) By simultaneously quenching through the high-side quenching sub-circuit of the SPAD cathode and the low-side quenching sub-circuit of the anode, the quenching depth of the SPAD can be doubled, so that the bias voltage of the SPAD can be increased to nearly twice the quenching voltage, and the detection efficiency of the SPAD can be increased by more than 25%;
[0031] (2) Due to the method of simultaneously quenching the high and low ends respectively, while increasing the quenching depth to obtain higher detection efficiency, the quenching voltage of a single quenching sub-circuit is not increased, thus ensuring that the quenching speed is not reduced.
[0032] (3) Using NPN-type and PNP-type RF transistors as high-speed control switches for the quenching and reset sub-circuits, the switching speed is increased to further reduce the dead time of the SPAD. The dead time can be controlled within 33 ns, and a saturation counting rate of about 30 MHz can be obtained, reducing the dead time by about 16% compared with the traditional method. Brief description of the drawings
[0033] Figure 1 is the schematic diagram of the SPAD passive quenching circuit;
[0034] Figure 2 is the schematic diagram of the SPAD gated quenching circuit;
[0035] Figure 3 is the schematic diagram of the SPAD active quenching circuit;
[0036] Figure 4 is the timing relationship diagram of the SPAD active quenching and reset control;
[0037] Figure 5 is the structural diagram of the fast quenching and reset circuit that can improve the SPAD detection efficiency of the present invention;
[0038] Figure 6 is the schematic diagram of the fast quenching and reset circuit that can improve the SPAD detection efficiency of the present invention. Detailed implementation manners
[0039] The present invention will be further described below with reference to the accompanying drawings.
[0040] As Figures 5-6 shown, a fast quenching and reset circuit that can improve the detection efficiency of a single-photon avalanche diode includes a high-side quenching sub-circuit, a high-side reset sub-circuit, a low-side quenching sub-circuit, a low-side reset sub-circuit, an avalanche diode D1, a sampling resistor R1, and a high-voltage power supply.
[0041] A high-side quenching sub-circuit is introduced at the cathode of the avalanche diode D1. The high-side quenching sub-circuit includes: an AC coupling capacitor C2, protection diodes D2 and D3, current-limiting resistors R4, R5, and R6, push-pull output transistors Q2 and Q3, a pull-up resistor R7, and a level-shifting transistor Q4, the avalanche diode D1, and a first quenching power supply.
[0042] The push-pull output transistor Q2 and the level-shifting transistor Q4 are NPN-type RF transistors, and the push-pull output transistor Q3 is a PNP-type RF transistor.
[0043] The base of the level-shifting transistor Q4 is the high-side quenching control port, the emitter is connected to the signal ground, and the collector is connected to the second end of the pull-up resistor R7; the first end of the pull-up resistor R7 is connected to the second end of the current-limiting resistor R4, and the first end of the current-limiting resistor R4 is connected to the output end of the first quenching power supply; the collector of the push-pull output transistor Q2 is connected to the second end of the current-limiting resistor R4, the base is connected to the second end of the current-limiting resistor R4, and the emitter is connected to the first end of the current-limiting resistor R5; the emitter of the push-pull output transistor Q3 is connected to the second end of the current-limiting resistor R6, the base is connected to the second end of the pull-up resistor R7, and the collector is connected to the signal ground; the second end of the current-limiting resistor R5 is connected to the first end of the current-limiting resistor R6; the anode of the protection diode D2 is connected to the cathode of the protection diode D3, the cathode of the protection diode D2 is connected to the second end of the current-limiting resistor R4; the anode of the protection diode D3 is connected to the signal ground; the second end of the AC coupling capacitor C2 is connected to the anode of the protection diode D2; the first end of the AC coupling capacitor C2 is connected to the cathode of the avalanche diode D1.
[0044] A high-side reset sub-circuit is introduced at the cathode of the avalanche diode D1. The high-side reset sub-circuit includes: bias resistors R2 and R3, an AC coupling capacitor C1, a radio frequency PNP transistor Q1, and an avalanche diode D1; the first end of the AC coupling capacitor C1 is the control port of the high-side reset sub-circuit; the first end of the AC coupling capacitor C2 is connected to the second end of the bias resistor R2, and the first end of the bias resistor R2 is connected to the emitter of the radio frequency PNP transistor Q1; the first end of the bias resistor R3 is connected to the first end of the AC coupling capacitor C1, and the second end of the bias resistor R3 is connected to the collector of the radio frequency PNP transistor Q1; the emitter of the radio frequency PNP transistor Q1 is connected to the output end of the high-voltage power supply, the collector is connected to the cathode of the avalanche diode D1, and the base is connected to the second end of the AC coupling capacitor C1;
[0045] A low-side quenching sub-circuit is introduced at the anode of the avalanche diode D1. The low-side quenching sub-circuit includes: an AC coupling capacitor C3, a current-limiting resistor R8, a pull-up resistor R9, a radio frequency PNP transistor Q5, protection diodes D4 and D5, an avalanche diode D1, and a quenching power supply; the first end of the AC coupling capacitor C3 is the control port of the low-side quenching sub-circuit; the second end of the AC coupling capacitor C3 is connected to the second end of the pull-up resistor R9; the first end of the pull-up resistor R9 is connected to the second end of the current-limiting resistor R8; the first end of the current-limiting resistor R8 is connected to the output end of the quenching power supply; the base of the radio frequency PNP transistor Q5 is connected to the second end of the AC coupling capacitor C3, the emitter is connected to the second end of the current-limiting resistor R8, and the collector is connected to the anode of the avalanche diode D1; the anode of the protection diode D4 is connected to the anode of the avalanche diode D1, and the cathode of the protection diode D4 is connected to the second end of the current-limiting resistor R8; the cathode of the protection diode D5 is connected to the anode of the avalanche diode D1, and the anode of the protection diode D5 is connected to the signal ground;
[0046] A low-side reset sub-circuit is introduced at the anode of the avalanche diode D1. The low-side reset sub-circuit includes: an avalanche diode D1, a sampling resistor R1, and a radio frequency NPN transistor Q6; the base of the radio frequency NPN transistor Q6 is the low-side reset control port; the emitter of the radio frequency NPN transistor Q6 is connected to the signal ground; the collector of the radio frequency NPN transistor Q6 is connected to the anode of the avalanche diode D1; the first end of the sampling resistor R1 is connected to the anode of the avalanche diode D1, and the second end of the sampling resistor R1 is connected to the signal ground.
[0047] As Figure 4As shown, the high-side and low-side quenching control ports are both effective at time t1: the low-side quenching control signal becomes low level, and the high-side quenching control signal becomes high level. The high-side and low-side quenching sub-circuits of the SPAD quench the cathode and anode of the SPAD simultaneously; after a duration of Δt1, the high-side and low-side quenching control ports are both ineffective at time t2: the low-side quenching control signal becomes high level, and the high-side quenching control signal becomes low level, and the SPAD quenching ends; at the end time t2 of the SPAD quenching, the signal of the low-side reset control port becomes high level, and starts to reset the anode of the SPAD; after a duration of Δt2, the low-side reset control port becomes low level, and the low-side reset ends; at the end time t3 of the low-side reset, the signal of the high-side reset control port becomes low level, and starts to reset the cathode of the SPAD; after a duration of Δt3, the high-side reset control port becomes high level, and the high-side reset ends; thus, a single quenching and reset cycle ends, and the SPAD is ready to receive the next photon signal detection.
[0048] The fast quenching and reset circuit for improving the detection efficiency of single-photon avalanche diodes according to the present invention first uses a high-side quenching sub-circuit and a low-side quenching sub-circuit to quench the avalanche current of the avalanche diode simultaneously, then uses a low-side reset sub-circuit to reset the anode voltage of the avalanche diode, and finally uses a high-side reset circuit to reset the cathode voltage of the avalanche diode, so that the avalanche diode returns to the ready state for generating the next avalanche current and receives single-photon signals. The present invention solves the problem of mutual restriction between the high detection efficiency and low dead time requirements of the SPAD in long-distance lidar ranging. Compared with the traditional quenching method, the detection efficiency of the avalanche diode is increased by about 25%, and the dead time is reduced by about 16%; among them, by designing the high-side reset sub-circuit, the problem of avalanche diode damage caused by excessive avalanche current can be effectively avoided.
[0049] As described above, it is only the specific implementation manner in the present invention, but the protection scope of the present invention is not limited thereto. Any transformation or replacement that can be understood and conceived by those familiar with the technology within the technical scope disclosed by the present invention should be covered within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
Claims
1. A fast quenching and reset circuit, characterized in that: The circuit includes a high-side quenching sub-circuit, a high-side reset sub-circuit, a low-side quenching sub-circuit, a low-side reset sub-circuit, an avalanche diode D1, a sampling resistor R1, and a high-voltage power supply; The cathode of the avalanche diode D1 is introduced into the high-side quenching sub-circuit; The high-side quenching sub-circuit includes: an AC coupling capacitor C2, protection diodes D2 and D3, current-limiting resistors R4, R5 and R6, push-pull output transistors Q2 and Q3, a pull-up resistor R7, and a level conversion transistor Q4, and a first quenching power supply; The push-pull output transistor Q2 and the level conversion transistor Q4 are NPN-type RF transistors, and the push-pull output transistor Q3 is a PNP-type RF transistor; The anode of the avalanche diode D1 is introduced into the low-side quenching sub-circuit; The low-side quenching sub-circuit includes: an AC coupling capacitor C3, a current-limiting resistor R8, a pull-up resistor R9, a transistor Q5, protection diodes D4 and D5, and a second quenching power supply; The transistor Q5 is a PNP-type RF transistor; The cathode of the avalanche diode D1 is introduced into the high-side reset sub-circuit; The high-side reset sub-circuit includes: bias resistors R2 and R3, an AC coupling capacitor C1, and a transistor Q1; The transistor Q1 is a PNP-type RF transistor; The anode of the avalanche diode D1 is introduced into the low-side reset sub-circuit; The low-side reset sub-circuit includes: an avalanche diode D1, a sampling resistor R1, and a transistor Q6; The transistor Q6 is an NPN-type RF transistor; The high-side quenching sub-circuit and the low-side quenching sub-circuit are configured to be simultaneously effective and have the same duration to quench the cathode and anode of the avalanche diode D1 simultaneously; after quenching, the low-side reset sub-circuit is immediately set to be effective to reset the anode of the avalanche diode D1; after the low-side reset is completed, the high-side reset sub-circuit is immediately set to be effective, and the cathode of the avalanche diode D1 is reset to the high-voltage power supply voltage, and the avalanche diode D1 is ready for the next avalanche excitation.
2. The fast quenching and reset circuit according to claim 1, wherein: In the high-side quenching sub-circuit, the base of the level-shifting transistor Q4 is the high-side quenching control port, the emitter is connected to the signal ground, and the collector is connected to the second end of the pull-up resistor R7; the first end of the pull-up resistor R7 is connected to the second end of the current-limiting resistor R4, and the first end of the current-limiting resistor R4 is connected to the output terminal of the first quenching power supply; the collector of the push-pull output transistor Q2 is connected to the second end of the current-limiting resistor R4, the base is connected to the second end of the current-limiting resistor R4, and the emitter is connected to the first end of the current-limiting resistor R5; the emitter of the push-pull output transistor Q3 is connected to the second end of the current-limiting resistor R6, the base is connected to the second end of the pull-up resistor R7, and the collector is connected to the signal ground; the second end of the current-limiting resistor R5 is connected to the first end of the current-limiting resistor R6; the anode of the protection diode D2 is connected to the cathode of the protection diode D3, and the cathode of the protection diode D2 is connected to the second end of the current-limiting resistor R4; the anode of the protection diode D3 is connected to the signal ground; the second end of the AC coupling capacitor C2 is connected to the anode of the protection diode D2; the first end of the AC coupling capacitor C2 is connected to the cathode of the avalanche diode D1.
3. A fast quenching and reset circuit according to claim 1, characterized in that: In the high-side reset sub-circuit, the first end of the AC coupling capacitor C1 is the control port of the high-side reset sub-circuit; the first end of the AC coupling capacitor C2 is connected to the second end of the bias resistor R2, and the first end of the bias resistor R2 is connected to the emitter of the transistor Q1; the first end of the bias resistor R3 is connected to the first end of the AC coupling capacitor, and the second end of the bias resistor R3 is connected to the collector of the transistor Q1; the emitter of the transistor Q1 is connected to the output terminal of the high-voltage power supply, the collector is connected to the cathode of the avalanche diode D1, and the base is connected to the second end of the AC coupling capacitor C1.
4. A fast quenching and reset circuit according to claim 1, characterized in that: In the low-side quenching sub-circuit, the first end of the AC coupling capacitor C3 is the control port of the low-side quenching sub-circuit; the second end of the AC coupling capacitor C3 is connected to the second end of the pull-up resistor R9; the first end of the pull-up resistor R9 is connected to the second end of the current-limiting resistor R8; the first end of the current-limiting resistor R8 is connected to the output terminal of the second quenching power supply; the base of the transistor Q5 is connected to the second end of the AC coupling capacitor C3, the emitter is connected to the second end of the current-limiting resistor R8, and the collector is connected to the anode of the avalanche diode D1; the anode of the protection diode D4 is connected to the anode of the avalanche diode D1, and the cathode of the protection diode D4 is connected to the second end of the current-limiting resistor R8; the cathode of the protection diode D5 is connected to the anode of the avalanche diode D1, and the anode of the protection diode D5 is connected to the signal ground.
5. A fast quenching and reset circuit according to claim 1, characterized in that: In the low-side reset sub-circuit, the base of the transistor Q6 is the low-side reset control port; the emitter of the transistor Q6 is connected to the signal ground, and the collector is connected to the anode of the avalanche diode D1; the first end of the sampling resistor R1 is connected to the anode of the avalanche diode D1, and the second end of the sampling resistor R1 is connected to the signal ground.
Citation Information
Patent Citations
Quenching and signal reading circuit applied to single-photon detector
CN103780852A
Quick quenching / resetting circuit of single photon avalanche diode detector and method thereof
CN110061727A