A high-efficiency, low-noise power solution for a dual-channel GNSS RF receiver

A high-efficiency low-noise power solution for a dual-channel GNSS RF receiver is presented. The power solution involves a DC-DC buck converter and a followed low-dropout regulator （LDO）. The pulsewidth-modulation （PWM） control method is adopted for better noise performance. An improved low-power highfrequency PWM control circuit is proposed, which halves the average quiescent current of the buck converter to 80 μA by periodically shutting down the OTA. The size of the output stage has also been optimized to achieve high efficiency under a light load condition. In addition, a novel soft-start circuit based on a current limiter has been implemented to avoid inrush current. Fabricated with commercial 180-nm CMOS technology, the DC-DC converter achieves a peak efficiency of 93.1% under a 2 MHz working frequency. The whole receiver consumes only 20.2 mA from a 3.3 V power supply and has a noise figure of 2.5 dB.