激光脉冲测距专用CMOS高速高增益读出芯片设计

Design of high speed and high gain CMOS readout chip for laser pulse ranging

摘要:

高增益、高带宽是激光回波脉冲处理电路基本要求。为此，本文对高速激光回波信号的CMOS集成电路结构设计进行了深入研究：设计了一种新型的RGC跨阻放大器作为前置放大器、采用改进型的自动增益控制的Cherry-Hooper级联作为电压宽带放大器，构成激光脉冲信号的接收通路，并在前置放大器中设计加入MOS_L技术来实现并联电感峰化以拓展电路带宽。基于0.5um的CMOS工艺，对其电路性能进行了仿真。结果表明：该信号处理电路的信号带宽为100MHz，相应于短脉冲信号的响应为3ns；直流增益达到141dB。另外，作为缓冲输入级的新型的RGC结构的输入阻抗仅117Ω，且输出电压的响应幅度为1V等，并对其电路的整体版图提出了具体设计方案及仿真结果的测试比较。

Abstract:

The requirements of precision, speed and range of laser ranging put forward the performance indexes of high gain and high bandwidth for the processing circuit of laser echo pulse. Therefore, the CMOS integrated circuit structure design of high-speed laser echo signal is deeply studied in this paper. A new RGC transresistance amplifier was designed as the preamplifier, and an improved cherry-Hooper cascade was used as the voltage broadband amplifier to form the receiving path of the laser pulse signal. MOS_L technology was designed and added into the preamplifier to realize the parallel inductance peakization to expand the circuit bandwidth.In terms of bias voltage, the off chip power supply is used to provide voltage in order to make the chip have more advantages in speed and noise control. Based on 0.5um CMOS process, the performance of the designed circuit is simulated. The results show that the performance parameters of the improved signal processing circuit have been further improved on the basis of predecessors: The signal bandwidth of the signal processing circuit is 100MHz, and the response of the short pulse signal is 3ns. The DC gain reaches 141dB. In addition, the input impedance of the new RGC structure as the buffer input stage is only 117Ω, and the response amplitude of the output voltage is 1V. The design scheme of the whole circuit layout and the test and comparison of the simulation results are presented.