CN-116466329-B - Analog front end receiving device based on linear laser radar

CN116466329BCN 116466329 BCN116466329 BCN 116466329BCN-116466329-B

Abstract

The application discloses an analog front end receiving device based on a linear laser radar, which comprises a transimpedance amplifier with a current signal input end, wherein the output end of the transimpedance amplifier is connected with the input end of a single-ended rotating differential circuit, the output end of the single-ended rotating differential circuit is sequentially connected with the input end of an equalizer after passing through a first direct current offset canceller, a post-amplifier and a second direct current offset canceller, the input end of an output buffer is connected with the output end of the equalizer, the equalizer is a two-stage source-stage degenerate equalizer and is constructed into a differential pair structure of source-stage parallel resistors and capacitors, the transimpedance amplifier is constructed into a resistor parallel structure, and the transimpedance amplifier comprises a common source feedforward resistor, a local negative feedback resistor RF1 and a resistor RF2. According to the front-end receiving device, the detection capability of the laser radar for long-distance weak signals can be improved, gain switching is supported to adapt to different ranging scenes, and the front-end receiving device has the advantages of being high in bandwidth, low in noise, large in ranging range, short in recovery time and high in reliability.

Inventors

ZHANG YIDAN
LIU LIYUAN
ZHANG ZHAO
LIU JIAN
WU NANJIAN

Assignees

中国科学院半导体研究所

Dates

Publication Date: 20260508
Application Date: 20230406

Claims (7)

1. An analog front end receiving device based on a linear lidar, comprising: A transimpedance amplifier (1), the transimpedance amplifier (1) having an input for a current signal; the output end of the transimpedance amplifier (1) is connected with the input end of the single-ended shunt differential circuit (2); The direct current offset canceller (3), the post-amplifier (4) and the equalizer (5), wherein the direct current offset canceller (3) comprises a first direct current offset canceller and a second direct current offset canceller, and the output end of the single-ended-to-differential circuit (2) is connected with the input end of the equalizer (5) after sequentially passing through the first direct current offset canceller, the post-amplifier (4) and the second direct current offset canceller; An output buffer (6), wherein the input end of the output buffer (6) is connected with the output end of the equalizer (5), the output of the output buffer (6) is negative voltage VON and positive voltage VOP in the differential voltage signal, The equalizer (5) is a two-stage source-stage degradation equalizer and is constructed to be a differential pair structure of source-stage parallel resistors and capacitors, the transimpedance amplifier (1) is constructed to be a resistor parallel structure, and the transimpedance amplifier (1) comprises a common source feedforward resistor, a local negative feedback resistor RF1 and a resistor RF2.
2. The analog front end receiving device according to claim 1, wherein the transimpedance amplifier (1) further comprises a core amplifier, the core amplifier is connected in parallel with the common source feedforward resistor and the resistor RF2, and the core amplifier is of a three-stage cascade inverter structure and comprises a first-stage inverter, a second-stage local negative feedback resistor RF1 and a third-stage inverter type voltage amplification electrode.
3. The analog front end receiving device according to claim 2, characterized in that the transimpedance amplifier (1) is dc-coupled with the single-ended-to-differential circuit (2), The single-ended to differential circuit (2) is composed of a differential voltage amplifier and a first low-pass network, wherein the input end of a differential pair in the differential voltage amplifier is connected with the output end of the transimpedance amplifier (1), and the output end of the differential pair in the differential voltage amplifier is connected with the first low-pass network.
4. An analog front end receiving device according to claim 3, characterized in that the source parallel resistance-capacitance of the equalizer (5) is an array of adjustable source degeneration resistance-capacitance.
5. Front-end receiving device according to claim 4, characterized in that the post-amplifier (4) has a differential pair structure of active stage degeneration resistors, both the local degeneration resistor RF1 and the source stage degeneration resistor being adjustable resistors.
6. The analog front end receiver according to claim 5, wherein the first DC offset canceller and the second DC offset canceller each have a second low pass network and cross-fed NMOS transistors, The first DC offset canceller is connected to the first low-pass network to cancel DC offset of the differential pair in the differential voltage amplifier, and the second DC offset canceller is connected to the differential pair in the post-amplifier (4) to cancel DC offset of the differential pair in the post-amplifier (4).
7. The analog front end receiving device according to claim 1, characterized in that the output buffer (6) is constructed as a three-stage connection structure, The first stage is a third direct current offset canceller (7), the third direct current offset canceller (7) is connected with the input end of the equalizer (5), the middle stage is a pre-buffer stage (8), the pre-buffer stage (8) is constructed into a differential pair structure with an active stage degradation resistor, the final stage is a buffer stage (9), and the buffer stage (9) is constructed into a source stage degradation type equalization structure.

Description

Analog front end receiving device based on linear laser radar Technical Field The application relates to the field of pulse laser radars based on a direct time-of-flight linear mode, in particular to an analog front end receiving device based on a linear laser radar. Background Pulsed laser detection and ranging is achieved by calculating the time of flight between the detector and the target, which is widely used in mapping, obstacle detection and unmanned fields. However, conventional TOF (time of flight) lidars cannot directly distinguish objects of the same distance but different reflectivities, and linear mode lidars can acquire amplitude information of laser echoes through linear mode biased Avalanche Photodiodes (APDs) while acquiring distance and intensity information of a detection target. In order to enlarge the detection distance and improve the detection precision, a narrow and wide pulse is generally adopted as a transmitting source of the linear laser radar, but the requirement on the bandwidth of a front-end device of a receiving circuit is also increased. Meanwhile, the requirements of the receiving circuit analog front-end device are different according to different ranging scenes. For long distance ranging, the receiving front-end device needs to keep high gain and low noise level in order to realize weak signal detection, and for short distance ranging, the receiving front-end device needs to keep low gain to prevent saturated output when the input current is large. Therefore, for bandwidth and ranging, it is highly desirable to provide a receiving circuit analog front-end device with high bandwidth, low noise, and switchable gain on the basis of a high-precision linear mode lidar. Disclosure of Invention In view of the above problems, the application provides an analog front end receiving device based on a linear laser radar, which improves the detection capability of a laser radar for long-distance weak signals, supports gain switching to adapt to different ranging scenes, and has the advantages of high bandwidth, low noise, large ranging range, short recovery time and high reliability. The application discloses an analog front end receiving device based on a linear laser radar, which comprises a transimpedance amplifier, a single-ended rotary differential circuit, a direct current offset canceller, a post-amplifier and an equalizer, wherein the transimpedance amplifier is provided with an input end of a current signal, the output end of the transimpedance amplifier is connected with the input end of the single-ended rotary differential circuit, the direct current offset canceller comprises a first direct current offset canceller and a second direct current offset canceller, the output end of the single-ended rotary differential circuit sequentially passes through the first direct current offset canceller, the post-amplifier and the second direct current offset canceller and then is connected with the input end of the equalizer, the input end of the output buffer is connected with the output end of the equalizer, the output of the output buffer is a negative voltage VON and a positive voltage VOP in differential voltage signals, the equalizer is a two-stage source-stage degradation equalizer and is constructed into a pair structure of source-stage parallel resistor capacitors, and the transimpedance amplifier is constructed into a resistor parallel structure, and the transimpedance amplifier comprises a common-source feedforward resistor, a local RF (RF) resistor (radio frequency) and a local RF (radio frequency) feedback resistor (radio frequency) 2). Further, the transimpedance amplifier also comprises a core amplifier, wherein the core amplifier is connected with the common source feedforward resistor and the resistor RF2 in parallel, and the core amplifier is of a three-stage cascade inverter structure and comprises a first-stage inverter, a second-stage local negative feedback resistor RF1 and a third-stage inverter type voltage amplification electrode. Further, the transimpedance amplifier and the single-ended differential circuit are in direct current coupling, the single-ended differential circuit is composed of a differential voltage amplifier and a first low-pass network, the input end of a differential pair in the differential voltage amplifier is connected to the output end of the transimpedance amplifier, and the output end of the differential pair in the differential voltage amplifier is connected to the first low-pass network. Further, the source parallel resistance-capacitance of the equalizer is an adjustable source degeneration resistance-capacitance array. Further, the post-amplifier has a differential pair structure with an active-stage degeneration resistor, and the local degeneration resistor RF1 and the active-stage degeneration resistor are both adjustable resistors 0 Further, the first DC offset canceller and the second DC offset canceller are provided with a se