Design of filter tuning circuit to compensate band width change of band pass filter by process and temperature

摘要

In this paper, we design a filter tuning circuit that uses the 55 nm CMOS process. When current is applied to the capacitor, the specific voltage charge time and the capacitance are proportional. By using this principle, capacitor is the same value and complex BPF can keep the same bandwidth automatically not being affected by the temperature and process. Complex BPF has center frequency of 1 MHz, bandwidth of 1.2 MHz and ac response of 12 dB.