The HFA5251 is a very high speed monolithic pin driver solution for high performance test systems. The device will switch at high data rates between two input voltage levels providing variable amplitude pulses. The output impedance is trimmed to achieve a precision 50 source for impedance matching. Two differential ECL/TTL compatible inputs control the operation of the HFA5251, one controlling the VHIGH /VLOW switching and the other controlling the output's high-impedance state. The HFA5251's 800MHz data rate makes it compatible with today's high-speed VLSI test systems and the +7V to -2V output swing allows testing of all common logic families.