-A 0.18μm CMOS MICS-band transceiver with a reconfigurable RF front-end is presented, reusing the same circuit core for super-regenerative wake-up receiver, receivemode LNA, and transmit power amplifier, eliminating the need for an external T/R switch. The transceiver uses an All Digital Frequency Locked-Loop (ADFLL) for LO signal generation and transmitter's modulation. The OOK wake-up receiver sensitivity is -80dBm @ 50kbps, while the BFSK receiver's sensitivity is -97dBm for a 75kbps signal and 2mW power consumption. The nominal output power of the transmitter is -5dBm.Index Terms -Medical Implantable Communication Services (MICS), implanted wireless sensor, ultra low power transceiver.