A new generation of uncooled passive infrared (PIR) security sensors based on a suspended transistor (TMOS) fabricated in standard CMOS-SOI process and released by post-etching, has been developed at the Technion, patented and is under development for commercial exploitation. This study focuses on the design of monolithically integrated readout for the electronic system, formed by the PIR sensor, its front-end analog interface and the processing circuitry.