The single 8-/12-bit buffered voltage-output DACs that operate from a single 2.5 to 5.5V supply, consuming 120microA at 3V. The on-chip output amplifier allows rail-to-rail output swing with a slew rate of 0.7 V/micros. It uses a 2-wire (I2C-compatible) serial interface that operates at clock rates up to 400kHz. Multiple devices can share the same bus. The reference for the DAC is derived from the power supply inputs and thus gives the widest dynamic output range. These parts incorporate a power-on reset circuit, which ensures that the DAC output powers up to 0 V and remains there until a valid write takes place. The parts contain a power-down feature that reduces the current consumption of the device to 50nA at 3V and provides software-selectable output loads while in power-down mode.