Modeling of an integrated active feedback preamplifier in a 0.25 μm CMOS technology at cryogenic temperatures

This paper describes the modeling of a standard 0.25 μm CMOS technology at cryogenic temperatures. In the first step of the work, the parameters of the EKV v2.6 model were extracted at different temperatures (300 K, 150 K, 70 K). The extracted parameters were then used to optimize the performance of a room temperature designed active feedback front-end preamplifier (AFP) at 130 K. The results show that with a small adjustment of the extracted parameters it is possible to have a reasonable model at low temperatures. By optimizing the bias conditions at 130 K a fall time down to 1.5 ns and a double pulse resolution of 6.5 ns were measured. The proposed approach will also allow a low temperature design optimization for future projects, which will not be possible using only standard models provided by the foundry.