A CMOS current mirroring integration readout structure for infrared focal plane arrays

This paper reports a new, high performance CMOS readout structure, called Current Mirroring Integration (CMI), for high-resolution infrared Focal Plane Array (FPA) applications. Using the integration capacitance outside the FPA, the unit cell area is decreased, making the circuit suitable for high-resolution applications. Moreover, the readout circuit offers high injection efficiency, perfect (almost-zero) detector bias, and large dynamic range in a small pixel area. The circuit provides a maximum charge storage capacity of 5.25×10⁷electrons and a maximum transimpedance of 6×10⁷Ω for a 2pF integration capacitance and 5V power supply. The unit-cell employs only nine MOS transistors and occupies an area of 20µm × 25µm in a 0.8µm CMOS process.