7.1 Overview

The DAC8881 is a single-channel, 16-bit, serial-input, voltage-output digital-to-analog converter (DAC). The architecture is an R-2R ladder configuration with the four MSBs segmented, followed by an operational amplifier that serves as a buffer, as shown in Figure 66. The on-chip output buffer allows rail-to-rail output swings while providing a low output impedance to drive loads. The DAC8881 operates from a single analog power supply that ranges from 2.7 V to 5.5 V, and typically consumes 850 μA when operating with a 3-V supply. Data are written to the device in a 16-bit word format, via an SPI serial interface. To enable compatibility with 1.8 V, 3 V, or 5 V logic families, an IOV_DD supply pin is provided. This pin allows the DAC8881 input and output logic to be powered from the same logic supply used to interface signals to and from the device. Internal voltage translators are included in the DAC8881 to interface digital signals to the device core. Separate AV_DD and DV_DD supply pins are provided, but should be connected together. See Figure 67 for the basic configuration of the DAC8881.

To ensure a known power-up state, the DAC8881 is designed with a power-on reset function. Upon power-up, the DAC8881 is reset to either zero-scale or midscale depending on the state of the RSTSEL pin. The device can also be hardware reset by using the RST and RSTSEL pins.

Figure 66. DAC8881 Architecture

Figure 67. Basic Configuration