A +10 dBm BLE Transmitter With Sub-400 pW Leakage for Ultra-Low Duty Cycles

A 2.4 GHz transmitter in 65 nm CMOS is optimized for extremely low duty-cycle regimes. Negative gate biasing of the main PA transistor in sleep mode achieves a 30× reduction in sleep-mode power without incurring on-performance degradation. The PA achieves a peak output power of +10.9 dBm and a total TX efficiency of 43.7%. A phase-locked loop is integrated, with direct modulation capability for the 1 Mbps GFSK modulation of Bluetooth Low Energy (BLE). The transmitter also includes a digital baseband with BLE support. Low voltage operation down to 0.68 V results in savings of both active switching power and leakage. Extensive power gating of all the blocks results in a total leakage of 370 pW for an on/off power ratio of 7.4×10 7 .