A 0.4-V, 500-MHz, ultra-low-power phase-locked loop for near-threshold voltage operation

摘要

We present a 500-MHz, ultra-low-power phase-locked loop (PLL) realized with the near-threshold supply voltage of 0.4 V in 65-nm CMOS technology. Our PLL employs a new charge pump (CP) circuit structure that can greatly reduce CP up/down current mismatch and their variation with voltage-controlled oscillator (VCO) control voltages. The PLL consumes only 127.8 μW, which corresponds to power efficiency of 0.256 mW/GHz.