关键词: 电流源, 77K, 亚阈值

Abstract: This paper gives a programmable current source in Readout-Integrated Circuit (ROIC) that is working in liquid nitrogen (77 K) without outside component. The design adopts MOS transistor working at sub-threshold region to enhance robust of circuit. The design uses 0.5 μm standard CMOS process with supply voltage of 5 V. From measurement result, In room temperature, output current varies from 199 nA to 212 nA with supply voltage variation from 2.3 V to 6.4 V, the precision is about 1.4%/V; In liquid nitrogen circumstance, output current varies from 355 nA to 372 nA with supply voltage variation from 3 V to 6.8 V, the precision is about 1.3%/V. As working temperature is stable, the current source's stability over temperature is not of importance.

Key words: current source, 77 K, sub-threshold