Description

The AD5421 is a complete, loop-powered, 4 mA to 20 mAdigital-to-analog converter (DAC) designed to meet the needsof smart transmitter manufacturers in the industrial controlindustry. The DAC provides a high precision, fully integrated,low cost solution in compact TSSOP and LFCSP packages.The AD5421 includes a regulated voltage output that is used topower itself and other devices in the transmitter. This regulatorprovides a regulated 1.8 V to 12 V output voltage. The AD5421also contains 1.22 V and 2.5 V references, thus eliminating theneed for a discrete regulator and voltage reference.The AD5421 can be used with standard Highway AddressableRemote Transducer (HART®) FSK protocol communicationcircuitry without any degradation in specified performance. Thehigh speed serial interface is capable of operating at 30 MHz andallows for simple connection to commonly used microprocessorsand microcontrollers via a SPI-compatible, 3-wire interface.The AD5421 is guaranteed monotonic to 16 bits. It provides0.0015% integral nonlinearity, 0.0012% offset error, and0.0006% gain error under typical conditions.The AD5421 is available in a 28-lead TSSOP and a 32-lead LFCSPspecified over the extended industrial temperature range of−40°C to +105°C.Applications Industrial Process Control 4 mA to 20 mA loop-powered transmitters Smart transmitters HART network connectivity