A Linear-Array Receiver Analog Front-End Circuit for Rotating Scanner LiDAR Application

A linear-array receiver analog front-end (AFE) circuit, which mainly consists of 16 transimpedance amplifiers (TIAs), is presented for pulsed time-of-flight (TOF) rotating scanner light detection and ranging (LiDAR) application. In particular, a single-channel TIA with a novel cascaded combination consists of a transimpedance preamplifier biased by a power supply of 1.8 V, a post amplifier (PA), and an output buffer (OB) with a 3.3-V power supply, aiming to lower the parasitic capacitance of the input stage and widen the output swing range, respectively. Meanwhile, the input-referred noise current is investigated to evaluate the detecting capability for the weak pulse current, and the crosstalk reduction schemes in circuit design and layout design are presented for the proposed AFE circuit. The proposed AFE circuit, which achieves a high gain of 100 dB Omega, a low gain of 60 dB Omega, a simulated transimpedance gain bandwidth of approximately 450 MHz, an equivalent input referred noise current of 2.59 pA/Hz(0.5), a signal-to-crosstalk ratio of 40.1 dB between adjacent channels, and a minimum detectable signal of 2.5 mu A at SNR = 5, was fabricated in a 0.18-mu m standard CMOS technology. The total area of AFE circuit, which includes the circuit core, bandgap and bias circuits, and I/O PAD, is approximately equal to 4.80 x 0.85 mm(2).