This letter introduces a method to optimize the temperature offset drift and noise efficiency factor (NEF) for chopper and auto-zero instrumentation amplifiers. In order to optimize offset drift and NEF, our proposed amplifier exploits a threshold voltage (Vth) tracking reference. A prototype of the proposed amplifier was fabricated using a standard 0.35μm complementary metal oxide semiconductor technology and occupies 0.174 mm2. Using the Vth tracking reference, an offset drift of 80 nV/℃ is achieved. The measured NEF was 2.45 with a supply current of 1.1 mA.
Park et al. (Thu,) studied this question.