A Programmable Gain Amplifier With Temperature Compensation for Hall Sensor

This letter presents a novel programmable gain amplifier (PGA) for Hall sensors, integrating temperature compensation and fuse trimming to reduce temperature drift and achieve variable sensitivity. To maintain a consistent gain over a wide temperature range, a Hall device, matching the shape and material of the Hall plates, with a negative temperature coefficient is used as the load, compensating for the temperature variations in the input signal from the Hall plates. High-order temperature compensation is used to ensure consistent sensitivity of the Hall sensor. Additionally, to accommodate a wide input signal range, a fuse trimming circuit is introduced to adjust the gain of the PGA. Using the GF180-nm BiCMOS process, the measurement results show that, when used in a Hall sensor, the sensitivity ranges from 1.8 mV/G to 15.8 mV/G, with a linearity error of less than 0.4% and a temperature sensitivity drift of less than 0.3% over the operational temperature range of −40∼140°C.