The UCC391 is a 5-bit, programmable-output precision voltage reference that’s a nice complement to any programmable-output dc-dc converter requiring precision low output voltages. The UCC391 device’s output voltage range can be set between 3.5V and 2.1V in 100-mV steps and from 2.05V to 1.3V in 50-mV steps with 1% dc system accuracy. Low input voltage (5V) operation eliminates need for a 12V rail.The device is compatible with Intel Pentium II microprocessor VID codes and is well suited for use by designers looking for additional control flexibility without taking up a lot of board space. Packaging options include 8-pin TSSOPs or mini-SO packages that occupy very little board area and height. The parts are specified for operation from 0°C to 70°C.