GENERAL DESCRIPTION
The AD421 is a complete, loop-powered, digital to 4 mA to 20 mA converter, designed to meet the needs of smart transmitter manufacturers in the Industrial Control industry. It provides a high precision, fully integrated, low cost solution in a compact 16-lead package. The AD421 is ideal for extending the resolution of smart 4 mA to 20 mA transmitters at very low cost.

FEATURES
    4 mA to 20 mA Current Output
    HART® Compatible
    16-Bit Resolution and Monotonicity
    0.01% Integral Nonlinearity
    5 V or 3 V Regulator Output
    2.5 V and 1.25 V Precision Reference
    750 A Quiescent Current max
    Programmable Alarm Current Capability
    Flexible High Speed Serial Interface
    16-Lead SOIC and PDIP Packages