Differential quantizer reference resistor ladder for use with an analog-to-digital converter

摘要

An analog-to-digital converter employing a reference resistor ladder is disclosed for quantizing a differential analog input signal into quantization levels and converting each level into binary output code and requiring comparators having only two inputs. The converter receives positive and negative portions of a differential analog input signal. A first resistive network having a plurality of resistors of equal resistance spreads the negative input portion of the signal to thereby provide a plurality of comparison signals. A second resistive network, likewise having a plurality of resistors of equal resistance being coupled in series spreads the positive input portion of the signal to thereby provide a second plurality of comparison signals. A plurality of two-input comparators are provided to compare the comparison signals provided by the first resistive network with the comparison signals of the second resistive network. The comparator outputs are then encoded to thereby provide an N-bit binary output code response.