A Low-Power Programmable Bandpass Filter Section for Higher Order Filter Applications

We present a programmable, continuous-time bandpass filter that is extremely compact, power efficient, and can cover a wide range of frequencies (10 Hz-10 MHz). This capacitively coupled current conveyor (
C

⁴
) has a second-order bandpass transfer function and is capable of being used as a basic bandpass-filter element to create high-order filters. The use of floating-gate transistors helps to ease the difficulties of effectively utilizing
G

_m
-
C
filters by providing precise, programmable current sources that set the filter's time constants. Additionally, we provide an algorithmic design approach for constructing these bandpass filters to meet any given specifications. This bandpass filter is ideally suited to large filter-bank applications because of its small size and low-power demands.