Readout Integrated Circuit (IC) Technology for Strained Layer Superlattice Photodetectors

The proposed program is a collaboration between Nu-Trek and Teledyne Imaging Sensors. In the proposed work we will develop a highly flexible ROIC designed for SLS detectors. The ROIC features include a state-of-the-art capacitive transimpedance amplifier (CTIA), snapshot integration, programmable gain, outstanding linearity, and in-cell correlated double sampling (CDS). Both n-on-p and p-on-n SLS devices will be accommodated, while a per-unit cell sample-and-hold (S/H) stage will enable high-efficiency imaging through integrate-while-read operation. A dual wavelength option will also be provided. An active-passive level shifting technique (APL) was invented to meet application requirements. It enables the CTIA to have low noise, high linearity, and low power consumption. The APLS will meet the challenging requirements of the SLS application while consuming 1/6th the power of conventional CTIA circuits. ROIC will also have on-chip data conversion using the ultra low power analog to digital converter under development at Nu-Trek. The reduced power consumption is enabling in field applications, such as unmanned vehicles and aircraft. In Phase I the unit cell will be designed, In Phase II the ROIC will be fabricated, hybridized to a Teledyne SLS detector and tested. BENEFIT: SLS detectors hold great promise, because of reduced Auger currents, which theoretically should lead to lower dark currents. Unfortunately, SLS has yet to live up to its potential. A key issue hampering progress is use of commercial ROICs designed for other (non-SLS) detectors. As a result, researchers have been struggling to accurately characterize SLS detector quantum efficiency and dark current – key parameters affecting FPA performance. The availability of a flexible, high end ROIC designed specifically for SLS detectors would facilitate progress. In the proposed work a highly flexible ROIC will be designed specifically for SLS detectors. With such a ROIC researchers are likely to make much faster progress. The ROIC is also very low power and has on-chip data conversion, make for a simpler FPA, which is enabling to applications such as unmanned vehicles and aircraft.