Area-efficient low-power bandpass Gm-C filter for epileptic seizure detection in 130nm CMOS
A low-power 6th-order Butterworth bandpass filter has been designed for the front-end of an integrated neural recording system. The passband has been set to 250-500Hz to allow recording the fast ripple (FR) associated with epileptic seizure onset and filter out all other undesired components of the neural signals. The filter is composed of 3 Gm-C biquad stages. Low-power operation is achieved by biasing the MOS devices in the sub-threshold region, and using a dual power supply of ±0.5V.