AD261AND-2

Overview

The AD261AND-2 is a high-speed digital isolator designed to isolate five digital control signals between a microcontroller and field I/O components. It features a 20 MHz minimum logic signal bandwidth and a propagation delay of 14 ns. The device provides an isolation test voltage up to 3.5 kV rms and a common-mode transient immunity (CMTI) of 10 kV/µs min. It operates within a supply voltage range of 4 V to 5.75 V and supports output enable/three-state functions via two dedicated pins. The component is housed in a 22-DIP package.

Feature Summary

• Provides galvanic isolation for five digital logic lines with high-speed data transmission capabilities.
• Maintains waveform edge transmission symmetry to accurately isolate time-based PWM signals.
• Includes dual enable pins allowing field and system outputs to be set to a high-resistance three-state level.

Applications

• PLC and DCS analog input/output cards
• IGBT motor drive controls
• High-speed digital I/O ports

Procurement Notes

Verify the specific suffix against official Analog Devices documentation to confirm pinout and electrical characteristics, as variations exist within the family. Confirm that the 22-DIP package matches the target PCB footprint requirements. Ensure the design accounts for the specified 4 V to 5.75 V supply range and thermal dissipation limits during operation.

Selection Notes

Select this component when replacing multiple opto-isolators to reduce board space and improve switching speed. It is suitable for applications requiring precise timing isolation, such as PWM control, due to its low propagation delay and edge symmetry. Consider the 3.5 kV rms isolation rating for safety compliance in industrial environments.

Part Context

The AD261 series replaces discrete opto-isolator solutions by integrating five isolated channels into a single module. This consolidation simplifies circuit design and improves reliability. The AD261AND-2 variant specifically utilizes a 22-pin DIP configuration, offering a legacy-compatible form factor for retrofitting or maintaining existing industrial control architectures.

Replacement Considerations

Direct substitutes include other models from the AD261 family, such as the AD261AN, which offer different I/O configurations. Verify that any replacement maintains the required 20 MHz bandwidth and 3.5 kVrms isolation voltage to ensure functional equivalence in high-speed isolation applications.

FAQ

How does the AD261AND-2 handle PWM signal isolation?

It maintains output waveform symmetry within ±1 ns of the input, allowing it to accurately isolate time-based PWM signals without distortion.

What is the purpose of the two enable pins on the AD261AND-2?

The two enable pins allow all field or system output pins to be set to a high-resistance three-state level, facilitating easy multiplexing and presetting logic levels at power-up.