The part features a simple 2-wire serial interface compatible with I2C that allows communication between many devices. The internal data registers are double buffered to allow for simultaneous update of several devices at once. The DAC can be put in low current power-down mode for use in power conscious systems. Power-on reset ensures the DAC output is at 0V when power is initially applied, and all internal registers are cleared. The LTC1669 is pin-for-pin compatible with the LTC1663.