Charge scaling 10-bit successive approximation A/D converter with reduced input capacitance

A low power 10-bit successive approximation A/D converter which is designed for implantable bioelectronics is presented. The converter has a charge scaling digital-to-analog converter which also samples the input signal. The charge scaling capacitance is in a split-capacitor configuration that has a total input capacitance which is 95.5 % smaller compared to a conventional design and 25%smaller compared to a conventional split-capacitor design. The converter operates at 308 kS/s and has a single-ended structure. The circuit is simulated with a 0.35 μm 4M2P CMOS process. Simulation results for the proposed A/D converter are presented.