A Subthreshold FoldedCascode Lowpass Biquad for Biopotential Acquisition This paper presents a subthreshold CMOS 2ndorder lowpass filter for lowfrequency biomedical signals discrimination. We modify the foldedcascode (FC) OTA to combine with two floating capacitors in a unitygain negative feedback configuration. Circuit simulation using 0.35 xcexbcm CMOS confirms that the proposed biquad, operated from a 1 V dc supply, consumes 15.15 nW to obtain a cutoff frequency of 152 Hz. With 52.5 pF total capacitance, the filter contributes an inputreferred noise of 31.6 xcexbcV rms . At cutoff frequency, when a 100 mV pp  sinusoidal input signal is applied, the filter produces 1.7% total harmonic distortion. This results in a filteru0027s dynamic range of 61 dB.

AreaEfficient LowPower Bandpass GmC Filter for Epileptic Seizure Detection in 130nm CMOS A lowpower 6thorder Butterworth bandpass filter has been designed for the frontend of an integrated neural recording system. The passband has been set to 250500Hz 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 GmC biquad stages. Lowpower operation is achieved by biasing the MOS devices in the subthreshold region, and using a dual power supply of xc2xb10.5V. The filter achieves a power consumption of  3.8 boldsymbolmumathbfW  with a load of 1pF, a bandwidth of 243Hz, and the estimated size of the layout is only 0.1mm2.