Abstract: A wideband fully differential programmable gain amplifier (PGA) was designed for RF chip with high accuracy which was implemented in SMIC 180 nm 1.8 V CMOS process.The PGA was composed of four serial stages with DC offset cancellation circuit and super-source-sollower.Measurement results showed that the PGA performed properly.It was controlled by a digital signal of six bits to realize a dynamic gain of 0 to 50 dB by 1dB step with a gain error less than 0.2 dB,the 1dB bandwith up to 75 M Hz and the 3 dB bandwith up to 110 M Hz. The amplifiers consumed less than 9 mA of power and the super-source-sollower consumed less than 8mA of power, which the circuit occupied a chip area of 518 μm×406 μm.