The DAC8740H and DAC8741H (DAC874xH) are HART®, FOUNDATION Fieldbus™, and PROFIBUS PA compatible low-power modems designed for industrial process control and industrial-automation applications. In HART mode, the DAC874xH integrates all of the required circuitry to operate as half-duplex HART physical layer modems, in either slave or master configurations with minimal external components for filtering. In FOUNDATION Fieldbus mode, the DAC874xH integrates all of the required circuitry to operate as half-duplex FOUNDATION Fieldbus compatible H1 controllers and MAUs. The HART, FOUNDATION Fieldbus, or PROFIBUS PA, data stream can be transferred from the microcontroller through either a UART interface or an integrated FIFO accessed by a SPI interface. The SPI interface includes an SDO pin for daisy-chain support, various interrupts, and other extended features.