Sung Min Park

Bio: Sung Min Park is an academic researcher. The author has contributed to research in topics: Avalanche photodiode & Minimum detectable signal. The author has co-authored 1 publications.

A CMOS Optoelectronic Receiver IC with an On-Chip Avalanche Photodiode for Home-Monitoring LiDAR Sensors

Abstract: This paper presents an optoelectronic receiver (Rx) IC with an on-chip avalanche photodiode (APD) realized in a 0.18-μm CMOS process for the applications of home-monitoring light detection and ranging (LiDAR) sensors, where the on-chip CMOS P+/N-well APD was implemented to avoid the unwanted signal distortion from bondwires and electro-static discharge (ESD) protection diodes. Various circuit techniques are exploited in this work, such as the feedforward transimpedance amplifier for high gain, and a limiting amplifier with negative impedance compensation for wide bandwidth. Measured results demonstrate 93.4-dBΩ transimpedance gain, 790-MHz bandwidth, 12-pA/√Hz noise current spectral density, 6.74-μApp minimum detectable signal that corresponds to the maximum detection range of 10 m, and 56.5-mW power dissipation from a 1.8-V supply. This optoelectronic Rx IC provides a potential for a low-cost low-power solution in the applications of home-monitoring LiDAR sensors.

An Indoor-Monitoring LiDAR Sensor for Patients with Alzheimer Disease Residing in Long-Term Care Facilities

Abstract: This paper introduces an indoor-monitoring LiDAR sensor for patients with Alzheimer disease residing in long-term care facilities (LTCFs), and this sensor exploits an optoelectronic analog front-end (AFE) to detect light signals from targets by utilizing on-chip avalanche photodiodes (APDs) realized in a 180 nm CMOS process and a neural processing unit (NPU) used for motion detection and decisions, especially for incidents of falls occurring in LTCFs. The AFE consists of an on-chip CMOS P+/N-well APD, a linear-mode transimpedance amplifier, a post-amplifier, and a time-to-digital converter, whereas the NPU exploits network sparsity and approximate processing elements for low-power operation. This work provides a potential solution of low-cost, low-power, indoor-monitoring LiDAR sensors for patients with Alzheimer disease in LTCFs.

An Optoelectronic Detector with High Precision for Compact Grating Encoder Application

Abstract: This paper presents a novel optoelectronic detection array that adopts the research idea of optical, mechanical and electrical integration. Through the design of new detectors and ASIC, the mutual restriction between high accuracy and miniaturization of the grating encoder is solved. A simulation model of the “broken line” detector structure and process was established that only meets the needs of a compact array layout but also ensures a good photoelectric conversion rate. In addition, we used a professional design program to complete the layout of the ASIC, which maximized the recovery of the signal received by the detector. The simulation and noise analysis results show that the SNRs of the output signal are greater than 60 dB with a 400 kHz response frequency.

A CMOS Fully Differential Optoelectronic Receiver for Short-Range LiDAR Sensors

Abstract: This article presents an optoelectronic receiver IC with on-chip avalanche photodiode (APD) realized in a 180-nm CMOS process for the applications of indoor-monitoring light detection and ranging (LiDAR) sensors. As an on-chip optical detector, a CMOS $\text{p}^{+}$ /n-well APD is integrated, thereby enabling to avoid unwanted signal distortion from bond-wires and electrostatic discharge (ESD) protection diodes. Various circuit techniques are exploited in this work, including the dual-feedback folded-cascode differential transimpedance amplifier (DFD-TIA) to achieve fully differential signaling from the input stage, an active single-to-differential (ASD) converter to minimize the inherent mismatches of the preceding DFD-TIA, a cross-coupled inverter-based postamplifier (CI-PA) to improve the symmetry of the output voltage swings, and a two-stage differential amplifier with negative impedance compensation (TDA-NIC) to obtain gain-boosting and wide bandwidth characteristics. Measured results of the proposed optoelectronic receiver IC demonstrate 87-dB $\cdot \Omega $ transimpedance gain, 577-MHz bandwidth, 15.4-pA/ $\surd $ Hz noise current spectral density, 4.18- $\mu \text{A}_{{\mathrm {pp}}}$ minimum detectable signal that corresponds to the maximum detection range of 10 m, and 50.6-mW power dissipation from a 1.8-V supply. Optical measurements utilizing an 850-nm laser diode with the average power of 10 mW reveal that the proposed optoelectronic receiver IC successfully recovers narrow 1-ns light pulses with the full-width at half-maximum (FHWM) of 840 ps even at the short distance of 50 cm. Hence, this work provides a potential solution for low-cost, low-power short-range LiDAR sensors.

Area and Bandwidth Enhancement of an n+/p-Well Dot Avalanche Photodiode in 0.35 μm CMOS Technology

Abstract: This paper presents a CMOS-integrated dot avalanche photodiode (dot-APD) that features a small central n+/p-well hemispherical cathode/p-well structure circularly surrounded by an anode ring. The dot-APD enables wide hemispherical depletion, charge collection from a large volume, and a small multiplication region. These features result in a large light-sensitive area, high responsivity and bandwidth, and exceptionally low junction capacitance. The active area can be further expanded using a multi-dot structure, which is an array of several cathode/p-well dots with a shared anode. Experimental results show that a 5 × 5 multi-dot APD with an active area of 70 μm × 70 μm achieves a bandwidth of 1.8 GHz, a responsivity of 9.7 A/W, and a capacitance of 27 fF. The structure of the multi-dot APD allows for the design of APDs in various sizes that offer high bandwidth and responsivity as an optical detector for various applications while still maintaining a small capacitance.