3.5 ns propagation delay — timing margin for high-speed threshold detection
The AD96687BRZ is a dual, high-speed comparator from Analog Devices with a latch function, designed for applications where propagation delay and setup/hold timing are critical. Its 3.5 ns max propagation delay places it in the class of comparators used for line receivers, pulse discriminators, window detectors, and ATE pin electronics, where every nanosecond of timing margin matters. The latch input allows the comparator to capture and hold the comparison result on a strobe signal, eliminating the need for an external flip-flop in sampled-data systems.
Complementary ECL outputs — logic-family and termination requirements
The complementary open-emitter ECL outputs are a defining feature: they provide both true and inverted outputs simultaneously, but they require external pull-down resistors to a negative supply (typically -5.2 V or -2 V) to set the logic levels. The 30 mA typical output current is enough to drive 50 Ω transmission lines terminated to -2 V, a common configuration in high-speed backplanes and test heads.
90 dB CMRR and 70 dB PSRR — noise rejection in mixed-signal environments
With 90 dB typical CMRR and 70 dB typical PSRR, the AD96687BRZ rejects common-mode noise and power-supply ripple well enough to maintain threshold accuracy in electrically noisy environments like industrial motor drives, switching power supplies, and telecom line cards. The 2 mV max input offset voltage at the rated supply voltages (-5.2 V and 5 V) is the static error budget the designer must account for; the 10 µA max input bias current is low enough that it does not dominate in most divider-network designs, but it should be checked against the source impedance of the input signal.
Lifecycle and supply posture
For dual-sourcing or a single-channel alternative, the AD96685BRZ is the same die in a single-comparator variant, sharing the 3.5 ns propagation delay, ECL outputs, and SOIC footprint — useful if a design only needs one comparator channel or if the second channel on the AD96687BRZ is unused and the BOM cost can be reduced.