This paper presents a SOI Hall sensor based microsystem for energy measurement. The mixed-mode signal circuitry has been entirely designed and integrated in the experimental 0.5 mu m fully depleted SOI 3 V technology. It consists of an integrated Hall element, chopper stabilized sensor bias system, analog front end and digital back end. Aiming at performing accurate measurements, we have implemented a high linearity analog front end, as well as a high-resolution analog-to-digital conversion technique. Two versions of the microsystem have been realized. The first test chip contains a classical instrumentation amplifier as sensor amplifier, whereas the second one contains a linearized differential-difference amplifier as sensor amplifier. Both microsystems are fully functional and permits one to perform the measurements with an overall system error that is less than 1.5%. (c) 2006 Elsevier Ltd. All rights reserved.