Low-voltage and low-power design is the key issue for the portable electronics applications and has become the major concern for the system design. Integrated gas sensor array allows the monolithic realization of multi-species gas sensing systems. This paper reports the developments of Si-based micro-machined micro-heater array with extremely low-power consumption, low-voltage operation, and CMOS compatibility, and low-voltage and low-power CMOS drive circuitry for the micro-heaters that can provide large drive current and voltage swing, and heater temperature is continuously adjustable in the full temperature range.