一种深低温环境LVDS驱动电路

A LVDS Driver Circuit for Deep Low Working Temperature

研究了深低温环境下MOS管与LVDS驱动电路的工作特性。与常温环境相比,LVDS电路在77K环境下的输出电流更大,导致输出差分信号幅值增大。MOS管在77K低温环境下的载流子迁移率为常温下的3倍,导致器件电流增大。根据低温条件下器件变化特性的数据分析结果,调节电路结构与器件参数,设置多档可调参考电流,并调节LVDS输出信号于标准范围内。采用标准0.35μm CMOS工艺进行流片验证。结果表明,LVDS驱动电路在77K环境下工作时,共模电平为1.2V,电压摆幅为400mV。

The characteristics of MOS devices and a LVDS drive circuit at deep low working temperatures was studied.LVDS driver’s output current at the working environment of 77K was higher than that ones at typical temperature,which had increased the amplitude of the LVDS driver’s differential signal.It showed that the current of the MOS transistor became larger as the carrier mobility increased by 2times at 77Kworking temperature.The structure and parameters of the circuit were adjusted according to the analysis data of the changes in characteristics of the MOS devices under low temperature conditions,and the referred currents were adjustable for multi-levels, the LVDS output signal was adjusted within the standard range.The circuit was taped out and verified in a 0.35μm standard CMOS process.The verification results showed that the LVDS driver’s common mode voltage was 1.2V, and the voltage swing was 400mV at 77Kworking temperature.