Pulse Research Lab (PRL) has launched the PRL-444, a four-channel TTL line driver. The compact, self-contained buffer pod drives four TTL/CMOS signals into 50-ohm loads. With a 10k (omega) input impedance, it can receive signals from devices with low drive current, such as sensors, PC-based digital I/O cards, satellite receivers and camera triggers. Each input has a 10k (omega) impedance pulled up to 2.5 V so that it also can be driven by open-collector devices. With 50-ohm load terminations, all outputs can drive 100 ft of 50-ohm cables at clock rates of more than 60 MHz.