MAX5120

19-1428; Rev 0; 2/99 +3V/+5V, 12-Bit, Serial Voltage-Output DACs with Internal Reference General Description The MAX5120/MAX5121 are low-power, 12-bit, voltageoutput digital-to-analog converters (DACs) with an internal precision bandgap reference and an output amplifier. The MAX5120 operates on a +5V supply with an internal amplifier reference of +2.5V and is capable of a +4.095V full-scale output range. The MAX5121, operating on +3V, delivers its +2.0475V full-scale output with an internal precision reference of +1.25V. If necessary, the user can override the internal, <10ppm/°C voltage reference with an external reference. Both devices draw only 500µA of supply current, which reduces to 3µA in power-down mode. In addition, their power-up reset feature allows for a user-selectable initial output state of either 0V or midscale and minimizes output voltage glitches during power-up. The serial interface is compatible with SPI™, QSPI™ and MICROWIRE™, which makes the MAX5120/ MAX5121 suitable for cascading multiple devices. Each DAC has a double-buffered input organized as an input register followed by a DAC register. A 16-bit shift register loads data into the input register. The DAC register may be updated independently or simultaneously with the input register. Both devices are available in a 16-pin QSOP package and are specified for the extended industrial (-40°C to +85°C) temperature range. For pin-compatible 14-bit upgrades, see the MAX5170/MAX5172 data sheet; for pin-comp...