A New Low-Power Non-uniform Sample and Hold Circuit for Biomedical Signal Processing Applications.

In this paper, a new non-uniform differential sample and hold circuit is proposed using low-distortion sampling switches for biomedical signal processing applications. The proposed design can be used in the biomedical low-frequency range with low-power consumption which makes the proposed design a good candidate for bio-signal sampling purposes. The body biasing technique is employed to reduce the distortion of the sampling switches. Moreover, to reduce the required sampled-data storage capacity, the signal slope rate detection is used to predict the input signal frequency and variations in order to adjust the proper sampling rate of the proposed non-uniform sampling circuit. To realize the proposed design, a capacitive digital-to-analog converter is used to sample the slope changes of signals at two sampling frequencies of 1000 and 100 Hz. The circuit simulation results using 0.18 μm CMOS technology parameters at 1 V supply voltage, indicate the saving in power consumption value up to 57.5% in comparison with other conventional designs. Additionally, the output signal of the proposed circuit can be reconstructed with a percentage root-mean-square difference factor of as low as 2.1%, a mean square error of 0.0025, and a signal-to-noise ratio value of 79.34 dB. [ABSTRACT FROM AUTHOR]