Resistor-capacitor (r-c) hybrid successive approximation register (sar) analog-to-digital converter (adc) with center-symmetric differential resistor string and other differential structures

Abstract

An analog-to-digital converter (ADC) includes a resistor network for generating multiple reference voltages. The resistor network includes multiple resistors connected in series to form a resistor string. A first portion of the resistors between either one of two end nodes and a central node of the string have substantially equal electrical resistances. A second portion of the resistors are refinements of at least part of the first portion resistors and are arranged further from the central node than the resistors of the first portion. Resistances of the second portion resistors are greater than resistances of the first portion resistors. When an electrical potential is applied between the two end nodes, the multiple reference voltages are produced between adjacent resistors. An ADC is also described including first and second capacitor arrays and a comparator. An apparatus and method are disclosed for generating a binary value corresponding to an analog input voltage.