The MAX520/MAX521 are quad/octal, 8-bit voltage-output digital-to-analog converters (DACs) with simple 2-wire serial interfaces that allow communication between multiple devices. They operate from a single +5V supply and their reference input range includes both supply rails. The MAX521 includes rail-to-rail output buffer amplifiers for reduced system size and component count when driving loads. The MAX520's unbuffered voltage outputs reduce the device's total supply current to 4µA and provide increased accuracy at low output currents. The MAX520/MAX521 feature a serial interface and internal software protocol, allowing communication at data rates up to 400kbps. The interface, combined with the double-buffered input configuration, allows the DAC registers to be updated individually or simultaneously. In addition, the devices can be put into a low-power shutdown mode that reduces supply current to 4µA. Power-on reset ensures the DAC outputs are at 0V when power is initially applied. The MAX520 is available in 16-pin DIP and wide SO packages, as well as a space-saving 20-pin SSOP. The MAX521 comes in 20-pin DIP and 24-pin SO packages, as well as a space-saving 24-pin SSOP.