The DAC121C081 is a 12-bit, single-channel, voltage-output digital-to-analog converter (DAC) that operates from a 2.7-V to 5.5-V supply. The output amplifier allows rail-to-rail output swing and has an 8.5-µs settling time. The DAC121C081 uses the supply voltage as the reference to provide the widest dynamic output range, and typically consumes 132 µA while operating at 5 V. It is available in 6-pin SOT and WSON packages, and provides three address options (pin selectable). As an alternative, the DAC121C085 provides nine I2C addressing options and uses an external reference. It has the same performance and settling time as the DAC121C081, and is available in an 8-lead VSSOP. The DAC121C081 and DAC121C085 use a 2-wire, I2C-compatible serial interface that operates in all three speed modes, including high-speed mode (3.4 MHz). An external address selection pin allows up to three DAC121C081 or nine DAC121C085 devices per 2-wire bus. Pin compatible alternatives to the DAC121C081 are available that provide additional address options. The DAC121C081 and DAC121C085 each have a 16-bit register that controls the mode of operation, the power-down condition, and the output voltage. A power-on reset circuit ensures that the DAC output powers up to 0 V. A power-down feature reduces power consumption to less than a microWatt. Their low power consumption and small packages make these DACs an excellent choice for use in battery-operated equipment. Each DAC operates over the extended industrial temperature range of −40°C to +125°C. The DAC121C081 and DAC121C085 are each part of a family of pin compatible DACs that also provide 8 and 10 bit resolution. For 8-bit DACs see the DAC081C081 and DAC081C085. For 10-bit DACs see the DAC101C081 and DAC101C085.