A 50-MHz dB-linear programmable-gain amplifier with 98-dB dynamic range and 2-dB gain steps for 3 V power supply

A programmable-gain amplifier (PGA) circuit introduced in this paper has a dynamic gain range of 98 dB with 2 dB gain steps and is controlled by 6-bit gain control bits for a 3 V power supply. It has been fabricated in a 0.5 (mu)m 15 GHz f/sub T/ Si BiCMOS process and draws 13 mA. The active die area taken up by the circuit is 400 (mu)m * 1170 (mu)m. A noise figure (NF) of 4.9 dB was measured at the maximum gain setting. In addition, an analysis of the bias current generation to provide dB-linear gain control is presented.