A 52 pJ/bit OOK transmitter with adaptable data rate

A 433-MHz OOK transmitter with adaptable data rate is presented. The proposed circuit completely turns off the transmitter during the transmission of ‘0’ and employs a speed-up scheme to obtain high data rates and low wake up time. The data rate can be adjusted and adapted to the need of applications. Realized in 0.35-μm CMOS technology, the OOK transmitter has a measured output power of −12.7dBm with a dc power consumption pf 560 μW under a 1-V power supply, and a data rate of 3 Mb/s, yielding an energy efficiency of 187 pJ/bit or 3.48 nJ/bit/mW if normalized to the transmitting power. When the proposed speed-up circuitry is enabled, data rate increases to 10 Mb/s, with a dc power consumption of 518 μW achieving a energy efficiency of 52 pJ/bit or 0.97 nJ/bit/mW when normalized.