AD202

The AD202 and AD204 are general purpose, two-port, transformer- coupled isolation amplifiers that may be used in a broad range of applications where input signals must be measured, processed, and/or transmitted without a galvanic connection.

These industry standard isolation amplifiers offer a complete isolation function, with both signal and power isolation provided for in a single compact plastic SIP or DIP style package. The primary distinction between the AD202 and the AD204 is that the AD202 is powered directly from a 15 V dc supply while the AD204 is powered by an externally supplied clock, such as the recommended AD246 Clock Driver.

The AD202 and AD204 provide total galvanic isolation between the input and output stages of the isolation amplifier through the use of internal transformer-coupling. The functionally complete AD202 and AD204 eliminate the need for an external, user-supplied dc-to-dc converter. This permits the designer to minimize the necessary circuit overhead and consequently reduce the overall design and component costs.

The design of the AD202 and AD204 emphasizes maximum flexibility and ease of use, including the availability of an uncommitted op amp on the input stage. They feature a bipolar ±5 V output range, an adjustable gain range of from 1V/V to 100 V/V, ± 0.025% max nonlinearity (K grade), 130 dB of CMR, and the AD204 consumes a low 35 mW of power.

The functional block diagrams can be seen in Figures 1a and 1b.