An Optoelectronic Transimpedance Amplifier in 180-nm CMOS for Short-range LiDAR Sensors

A Current-Mode Optoelectronic Receiver IC for Short-Range LiDAR Sensors in 180 nm CMOS

“…This section describes three different types of CMOS APDs in detail, which include a P + /N-well (NW) APD, a P + /Deep N-well (DNW) APD, and a P + /NW/DNW APD. These three structures are suggested to compare their performance in terms of responsivity, bandwidth, and breakdown voltage [4][5][6].…”

“…Figure 2 illustrates the cross-sectional view of the on-chip CMOS P + /NW APD formed by a P + /NW junction and an NW/P-substrate junction. Here, the avalanche multiplication is initiated by a hole in the P + /NW junction [4,5]. The P + contacts shown in the mid-region are connected to the front-end TIA, thereby excluding the slow diffusion currents contributed from the P-substrate, and thus providing the characteristics of high responsivity and large bandwidth.…”

“…An optoelectronic optical receiver IC with the suggested on-chip APDs was realized in a TSMC 180 nm CMOS process to verify the feasibilities for the applications of shortrange LiDAR sensors. As a front-end transimpedance amplifier (TIA), a conventional voltage-mode feedforward input circuit (VFIC) is exploited in this work since it can provide low-noise high-gain performance [5]. Figure 8 shows the block diagram of the voltage-mode optoelectronic receiver (V-OER) which consists of an APD as an optical detector, a VFIC as a TIA to convert the generated photocurrents to electrical voltages, a single-to-differential (S2D) converter for differential signaling, a differential gain stage for gain boosting, and a cross-coupled inverter post-amplifier (CI-PA) for offset cancellation.…”

“…In addition, on-chip electro-static discharge (ESD) protection diodes are mostly necessary to avoid the chip damage from the ESD, which may yet shrink the receiver bandwidth considerably. Several research works have been conducted to develop on-chip optical detectors implemented in bulk CMOS processes [2][3][4][5][6][7][8]. Although they inherently suffer from low responsivity and narrow bandwidth [2], the on-chip CMOS APDs can be an effective solution to overcome the aforementioned shortcomings, particularly for the applications of short-range LiDAR sensors [3][4][5].…”

“…Several research works have been conducted to develop on-chip optical detectors implemented in bulk CMOS processes [2][3][4][5][6][7][8]. Although they inherently suffer from low responsivity and narrow bandwidth [2], the on-chip CMOS APDs can be an effective solution to overcome the aforementioned shortcomings, particularly for the applications of short-range LiDAR sensors [3][4][5].…”