Signal processing system and method of reducing switch error attributable to switch impedances

摘要

A system and method minimizing switching errors in voltages delivered to a resistive load. Switch impedances can be significant when small resistor values are utilized. A system relies on varying the resistance in the switches to compensate for the output voltage errors. The selection of a particular CMOS input transmission gate depends upon which outputs of a resistor divider are selected. In concept, a system is created which replaces each input transmission gate with a resistor and a zero impedance switch. The combination of properly selected CMOS input transmission gates results in output offset voltage errors which are greatly reduced due to the matching impedances of the individual switches.