AD693AQ (ANALOG DEVICES)

The AD693AQ is a Loop-powered Sensor Transmitter which accepts low-level inputs from a variety of transducers to control a standard 4 to 20mA, Two-Wire current loop. An on-chip voltage reference and auxiliary amplifier are provided for transducer excitation, up to 3.5mA of excitation current is available when the device is operated in the loop-powered mode. Alternatively, the device may be locally powered for three-wire applications when 0 to 20mA operation is desired. Active laser trimming of the AD693's thin-film resistors result in high levels of accuracy without the need for additional adjustments and calibration. Total unadjusted error is tested on every device to be less than 0.5% of full scale at +25°C and less than 0.75% over the industrial temperature range. Residual nonlinearity is under 0.05%.