METHOD AND APPARATUS FOR DIGITAL TO ANALOG CONVERTERS WITH IMPROVED SWITCHED R-2R LADDERS

摘要

Operating range of R-2R ladders for digital to analog converters (DACs) is improved by increasing resistance in series with a termination switch in a termination leg to avoid transistor saturation for increasing DAC resolution, increasing reference voltage range, or other application. The switched R-2R ladder circuit is modified to compensate for increasing resistance to maintain proper resistor matching for generation of the appropriate range of analog output voltages for a digital input signal.