Chip Delivers Tightly Regulated Voltage For Use In VME64 Bus Systems

Providing current for up to 32 lines of active termination for a VME64 parallel bus, the UC563 bus regulator terminates both ends of the bus and offers all the functionality and performance necessary to bias terminate resistors for VMEbus industrial and communications computer systems. The device provides a 2.94V regulated output voltage with a 1% tolerance at 25°C, ensuring a high-accuracy pull-up current. With a 194 ohm resistor, it is able to provide a higher pull-up current for the bus than passive termination devices. To help prevent damage to the chip and system, the new IC is internally current limited for both sinking and sourcing current and offers a thermal shutdown protection feature. The 32-line VMEbus bias generator also delivers a -575 mA sourcing current for termination and a +475 mA sinking current for active negation drivers. Housed in an industry-standard 8-pin power SOIC package, the bus regulator is priced at $1.93 each/1,000.