Isolation Amplifiers

Drop-in. Pinout and package match the original part, so an AD202KNATI goes into a board laid out for an AD202KN with no changes to the layout or the supporting components. What changes is performance: the replacement is faster and, in most grades, more linear. If your circuit was designed around the original part's bandwidth limit — using it as a filter, for instance — that is worth a look before you swap, because the new part will pass signals the old one attenuated.

In a three-port design the input, the output and the power supply are all isolated from one another, rather than the power sharing a common with one side. The practical consequence is flexibility: the module can be used as an input isolator or an output isolator without redesign, and in a multichannel system each channel can sit at a different potential while sharing one supply. The AD210ATI is the three-port family here. If you have one signal going one direction and a single ground reference, you do not need it.

Multiply the rms figure by about 1.4 to get the equivalent peak, or divide a peak figure by 1.4 to approximate rms. We quote rms on this page because that is the value tested on every unit, and each datasheet gives the paired peak rating alongside it: 750 V rms with ±1000 V peak, 1500 V rms with ±2000 V peak, 2500 V rms with ±3500 V peak. Check which convention a competing datasheet uses before you compare — a part quoted at 2500 V rms is not weaker than one quoted at ±3000 V peak, it is stronger.

No. Every family here generates its isolated supplies internally from a single input supply, which is the main reason these modules replace a subcircuit rather than a component. Some of them go further and make that isolated rail available to you: the AD215ATI provides ±15 V at ±10 mA at its input port for a front-end amplifier, signal conditioning or transducer excitation.

There is a design change in the AD202ATI's history marked by serial number. In the DIP parts, units numbered up to 25156 have an output that is not isolated from the power supply and a 20 kHz bandwidth; above that number the output is isolated and the bandwidth is 800 kHz. For the SIP parts the boundary is 25290. The earlier version is out of production. If you are comparing two units or matching a board built around an early part, check the serial number before assuming a fault, and tell us if you need help identifying what you have. The same applies to our older ATIA202KN and ATIA202KY, which are discontinued and replaced identically by the AD202KNATI and AD202KYATI.

Isolation voltage is what the barrier survives; common-mode rejection is how well the amplifier ignores voltage that appears on both inputs at once. A part can have a very high isolation rating and still let common-mode noise contaminate your measurement, or excellent rejection and an inadequate barrier for your fault case. You need both specified for your application: the barrier sized for the worst voltage the input side can reach, and the rejection sized against the interference you are trying to keep out of the reading.

Analog Devices retired its modular product line, and the AD202, AD210 and AD215 went with it — announced in October 2022, last orders in 2023, last shipments in October 2024. These were never ordinary chips: each is a potted module with transformers and discrete components inside, assembled rather than fabricated, which is why an aging line of them was retired together rather than individually. The discontinuance notice named no replacement and no pin-compatible alternative, and the manufacturer's modern digital isolators are a different kind of device that would mean redesigning your board. That leaves three options: buy remaining stock from brokers at broker prices and hope it lasts, redesign the circuit, or fit a drop-in replacement. We build the third one.

Yes, and this is one place where the replacement is not merely equivalent to the original. The parts these supersede were sold as non-RoHS, so anyone shipping into a market with compliance requirements had a problem with them independently of the obsolescence. Ask us and we will send the documentation.

Our datasheets carry a stated guarantee of production for at least ten years. We build these because the original manufacturer stopped, and the customers who buy them are typically maintaining equipment with a long service life, so continuity is the point of the product rather than a nice extra. If you are planning a build or a lifetime buy, tell us the quantity and the horizon and we will confirm against the schedule.

If you are replacing an existing part, the answer is already decided — add ATI to the number on the module. For a new design, take it in this order. Isolation first: pick a rating that exceeds the worst-case voltage across the barrier including faults, not just normal operation. Then accuracy: if you need better than ±0.02 %, the AD215ATI is the only family here that offers it, and within it the BY grade reaches ±0.005 %. Then bandwidth, which is generous across all three and rarely the constraint. Within the AD202 and AD210 families the grade letter buys isolation voltage rather than accuracy, so paying up for a higher grade you do not need gains you nothing.