A 400µW differential FBAR sensor interface IC with digital readout

A low-power sensor interface IC suitable for a differential frequency measurement application is demonstrated. The circuit is used in a FBAR sensor system which includes a sensor and a reference FBAR. The sensor signal is processed and a digital output representing the sensor input is transmitted using a two wire serial interface. The architecture is entirely digital and benefits from scaling to advanced nodes. The IC is implemented in a 130nm CMOS process and consumes 400μW from a 0.75V supply.