AD8611ARZ-REEL7

Overview

The AD8611ARZ-REEL7 is a single-channel ultrafast comparator from Analog Devices, housed in an 8-lead narrow body SOIC package. It operates on a single supply voltage ranging from 3 V to 5 V. The device features a typical propagation delay of 4 ns and a maximum of 5.5 ns at 5 V. It includes a latch function that requires VCC greater than 4.3 V to operate. Key electrical parameters include a maximum input offset voltage of 7 mV, a common-mode rejection ratio of 85 dB, and a power supply rejection ratio of 73 dB. The input bias current is typically -4 μA, with a maximum of -7 μA across the industrial temperature range of -40°C to +85°C.

Feature Summary

• Features complementary digital outputs for direct interface with logic circuits.
• Includes a latch function to maintain output state independent of subsequent input changes.
• Offers closely matched propagation delays for rising and falling signals to preserve duty cycle accuracy.
• Provides a wide common-mode input range extending down to the negative supply rail.

Applications

• High speed timing circuits
• Clock recovery and clock distribution systems
• Line receivers
• Digital communications phase detectors
• High speed analog-to-digital converter (ADC) read channel detection

Procurement Notes

Verify the specific suffix REEL7 corresponds to reel packaging when sourcing. Confirm the manufacturer part number matches Analog Devices specifications. Ensure the component meets RoHS compliance requirements for your assembly process. Check datasheet revisions for any updates to absolute maximum ratings or thermal resistance values before finalizing design integration.

Selection Notes

Select this component for applications requiring sub-5 ns response times within a single-supply environment. It serves as a pin-compatible upgrade for LT1016 and LT1394 designs, offering lower power consumption and wider input ranges. Consider the latch functionality if holding signal states is required. Ensure source impedance remains below 1 kΩ to optimize high-speed performance and minimize delay variations caused by input capacitance.

Part Context

This device belongs to the AD8611/AD8612 family of ultrafast comparators. While the AD8611 provides a single channel, the AD8612 offers dual channels in a 14-lead TSSOP package. Both share identical electrical characteristics and pinouts for their respective channels. The AD8611 is available in both 8-lead MSOP and narrow 8-lead SOIC packages, providing flexibility for different board space constraints.

Replacement Considerations

The AD8611 is pin-for-pin compatible with the LT1016 and LT1394. When replacing these legacy parts, account for differences in input voltage range, bias current direction, and propagation delay. The AD8611 draws less supply current but has a different input common-mode specification that may require signal shifting if original operating points are exceeded.

FAQ

Does the latch function work at all supply voltages?

No, the latch function is not functional if the supply voltage (VCC) is less than 4.3 V. For proper operation, the supply must exceed this threshold.

How does the AD8611 compare to the LT1016 regarding input bias current?

The AD8611 has a maximum input bias current of 7 μA, which is half of the maximum bias current specified for the LT1016. Additionally, the AD8611 bias currents flow out of the inputs, whereas the LT1016 currents flow into them.

What is the maximum recommended input frequency for accurate comparison?

The AD8611 can accurately compare input signals up to 100 MHz. Using frequencies significantly above this limit may cause excessive supply current draw and prevent outputs from settling properly.