A CMOS inductorless MedRadio OOK transceiver with a 42 μW event-driven supply-modulated RX and a 14% efficiency TX for medical implants

An inductorless MedRadio (413∼419 MHz) OOK transceiver for an implantable brain-machine interface (BMI) in 180 nm CMOS is presented. An event-driven supply modulation (EDSM) technique is introduced in the receiver to lower the power consumption to 42/92 μW at 1/10 kbps, achieving −79/−74 dBm sensitivity (at 0.1% BER). The transmitter employs a current-starved ring oscillator with an automatic frequency calibration loop, achieving 14% efficiency for random OOK data at −4 dBm output power. Wireless connection, benchtop, multi-user coexistence, and in-vitro phantom test results are demonstrated.