The EL2021 is designed to drive programmed voltages into difficult loads. It has the required circuitry to be used as the pin driver electronics in board test systems. Capable of overpowering logic outputs, the part can accurately drive independently set high and low levels with programmed Slew Rates into reactive loads. It can also be placed into high impedance to monitor the load without having to disconnect. Previous board testers had multiplexing schemes to reduce the number of pin drivers required. With the small size and power consumption of the monolithic EL2021, a driver per node with little or no multiplexing becomes practical. Since only a few pins of "bed-of-nails" board testers need be active at any given time, the power-down feature saves substantial power in large systems.