A 56µW VGA with 5MHz bandwidth and 47dB gain-range in 90nm CMOS

This paper presents the design and implementation of a variable gain amplifier with an ultra low-power consumption of 56μW. This is achieved by using sub-threshold operation, 1V power supply and a minimum amount of current branches. After system-level optimization, a gain range of 47dB is implemented with 6dB per step programmability. The SNDR is better than 33dB for all gain settings, while the nominal signal bandwidth is 5MHz. The performance is measured on a test-chip in a 90nm CMOS technology.