A Multi-Channel MCP-PMT Based Readout Integrated Circuit for LiDAR Applications

Photon counting techniques are becoming more critical in fields such as LiDAR, high energy physics (HEP), and positron emission tomography (PET). For space-based aerosol-cloud-ocean (ACO) LiDAR, the total aggregate photon flux signal has a very high dynamic range, from a single-photon up to giga-photons per second for a single channel. This dissertation focuses on the design of a multichannel, photon counting readout circuit that can interface with MCP-PMTs for high dynamic range, space-based LiDAR applications. Chapter 2 presents the conventional current mode approach that has been employed to realize a photon counting circuit. A transimpedance amplifier, a 6-bit delay line based time to digital converter (TDC), and an 8-bit ring oscillator based time to digital converter were designed and implemented in AMS’ 350nm SiGe BiCMOS process. Measurement results showed that the transimpedance amplifier has a gain of 14 KΩ and a bandwidth of 96 MHz. Similarly, the delay line based TDC and ring oscillator based TDC have a timing resolution of 530 ps and 534 ps respectively. The resolution of the ring oscillator based TDC can be tuned between 534 ps to 691 ps, thus making it useful for various applications. The performance of the photon counting circuits were improved using the proposed circuits that are presented in Chapter 3. A multi-channel current mode photon counting circuit and a high speed current mode summing circuit were designed, simulated, and fabricated in a TowerJazz’s 180 nm SiGe BiCMOS process. The measurement results convey that the proposed photon counting circuit can detect current pulses of 5 ns FWHM pulse width at amplitudes of 24 µA to 1.3 mA. The photon counting circuit was also tested for high speed and was able to detect signals with a 2 ns pulse width. A high speed current mode summing circuit also detects the pulse width of 5 ns, but with a lower input current range of 100 uA. The proposed photon counting circuit can be used as the front end readout for long range LiDAR applications. The key contributions in this dissertation includes: 1) Design of a wide input range, high speed, current mode readout circuit; 2) Design of a high speed current mode summing circuit; 3) Development of radiation hard circuits and layouts; 4) Investigation and improvement of existing TDC architectures with variable timing resolution; 5) Implementation of extensive testing techniques to validate the results