Low Voltage Digitally Programmable Band-Pass Filter with Independent Control

A digitally programmable second-order band-pass filter (BPF) with independently programmable characteristics is presented in this paper. The proposed BPF is based on a new ±0.75V second-generation current conveyor (CCII) with digital current gain control. The input stage of the CCII is realized using two complementary MOS differential pairs connected in parallel to ensure rail-to-rail operation. The output stage consists of a class-AB push-pull network, which guarantees high current driving capability and a 47.2 ¿A standby current. The programmability of the CCII, based on transistor arrays and MOS switches, provides variable current gain using an n-bits code-word. The proposed circuits are simulated using PSPICE with CMOS TSMC 0.25 ¿m technology.