45-nm CMOS Inverter Transimpedance Amplifier for LiDAR Applications

This paper presents the design of a low-power, high-gain inverter-based transimpedance amplifier (INV-TIA) tailored for Light Detection and Ranging (LiDAR) applications. LiDAR systems require TIAs that can efficiently convert optical signals into electrical signals, making it crucial to optimize both gain and bandwidth to handle the fast light pulses involved. The design proposed in this study addresses these needs by balancing high gain with wide bandwidth, ensuring robust performance across a range of operational conditions. A comprehensive review of similar designs led to the decision to implement the TIA using advanced 45 nm CMOS technology, which offers the advantages of compactness, energy efficiency, and high-speed performance. The circuit operates with a low 0.83 V DC power supply, consuming only 245 µW, which is ideal for portable and battery-powered LiDAR systems. Extensive SPICE simulations using the 45 nm CMOS library were conducted to validate the design. The TIA was evaluated under two scenarios: in high-gain mode, the circuit achieves a transimpedance gain of 91 dB and a bandwidth of 114 MHz, while in low-gain mode, the gain drops to 82 dB, but the bandwidth expands significantly to 297 MHz. These results demonstrate the potential of the proposed INV-TIA for efficient, high-performance LiDAR systems, offering both low power consumption and versatility.