This paper presents a active band-pass filter (BPF) for chopper frequency rejection. band pass filter consists of 2 Sallen-Key low-pass filter (LPF) and 3 feed forward high-pass filter (HPF). The LPF can adjust the cutoff freqeuncy through a 3 bit control, and the HPF can adjust the gain from 0 to 18 dB with 2 bit control. The BPF is designed and fabricated on CMOS 0.18 μm process.