A low power auto-reconfigurable pipelined ADC for implantable biomedical applications

This paper demonstrates a reconfigurable, pipelined analog-to-digital converter (ADC) that is designed for ultra-low power consumption through the use of weak inversion region-biased transistors. In addition, the converter is able to reconfigure itself into three different modes of operation based on the input signal or a third party signal such as body motion. An adaptation unit is presented which automatically distinguishes high frequency biosignals from low frequency ones and configures the ADC in the appropriate mode of operation. The adaptation unit gives two-bits of control selecting between 8-bit or 10-bit resolution and 73.7 KS/s or 737 KS/s sampling rate. The power consumption of the pipelined ADC and adaptation unit are 680 μW and 180 μW, respectively, with a 1.8 V supply voltage. The core circuit occupies only 0.425 mm2 area.