A highly linear programmable gain amplifier with level shifter and class AB output stage for bluetooth low energy

A highly linear PGA with level shifter and class AB output stage for BLE receiver is reported in this paper. Both merits of degenerated PGA and operational amplifier based PGA are synthesized in proposed PGA. It is implemented in 0.18μm CMOS process and draws 290μA current from a supply of 1.8V when driving a capacitor load of 2p at the IF of 1MHz, while high SR up to 2. 2 × 10⁷V/s is obtained. OIP3 of 40dBm is achieved under all gain modes due to the constant loop bandwidth. Proposed PGA has a gain range from 0dB to 14dB at the step of 2dB. The THD reaches 72.7dB at the frequency of 1MHz when proposed PGA outputs a 1.3Vpp differential voltage signal.