LT685CN

Overview

The LT685CN is a high-speed comparator manufactured by Analog Devices Inc. It features ultrafast propagation delay and complementary ECL-compatible outputs capable of driving 50Ω transmission lines. The device includes an output latch function for sample-hold mode operation and external hysteresis control to improve switching stability with slow input signals. Designed for low offset voltage and high resolution, it supports applications in high-speed analog-to-digital conversion and sampling circuits.

Feature Summary

• Ultrafast propagation speed with complementary ECL logic level outputs
• Integrated output latch capability for sample-hold functionality
• External hysteresis control via a dedicated pin to minimize oscillation
• Low input offset voltage ensuring high resolution performance

Applications

• High-speed analog-to-digital converters
• High-speed sampling circuits
• Oscillators

Procurement Notes

Verify the specific package configuration required for the LT685CN variant, as datasheet documentation indicates obsolete packages such as the N16 CERDIP. Confirm current availability status directly with the manufacturer or authorized distributors, as legacy components may have limited supply chains or require alternative sourcing strategies.

Selection Notes

Select the LT685CN when ECL compatibility and sub-10ns response times are critical. Ensure the design accommodates the specified dual power supply requirements and accounts for the latch enable timing constraints. Verify that the operating temperature range aligns with the C-grade specification limits provided in the electrical characteristics table.

Part Context

The LT685 series represents a family of ultrafast comparators designed for demanding signal processing tasks. The LT685CN specifically denotes the commercial grade version housed in a standard plastic package. This component serves as a direct replacement for legacy Am685 devices, maintaining pin compatibility while offering modernized performance metrics for industrial and communication systems.

Replacement Considerations

Datasheet notes indicate the N16 package is obsolete; consider the H Package (TO-5 Metal Can) as an alternate source. Verify pinout compatibility if substituting with other Am685 derivatives.