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

摘要： 给出了一种应用于低温光敏探测器读出电路的可编程电流源，工作在液氮环境（77 K），无外加单元，与一般电流源设计不同，本设计将部分MOS管设计在亚阈值区工作来提高电路工作稳定性。此电流源设计采用0.5 μm标准CMOS工艺。工作电压为5 V。室温测试当工作电压从2.3 V到6.4 V变化时，输出电流从199 nA变化到212 nA，精度为1.4%/V。在液氮环境测试当工作电压从3V到6.8 V变化时，输出电流从355 nA变化到372 nA，精度为1.3%/V。由于电路工作温度稳定，所以不要求电流源有良好的对温度稳定性。

关键词: 电流源, 77K, 亚阈值