Dual comparator with 210 ns propagation delay
The MAX991EUA+: The 210 ns max propagation delay suits medium-speed threshold detection, zero-crossing, and window-comparator circuits where the signal rate stays below a few megahertz.
The dual-supply option (±1.25 V to ±2.75 V) allows direct interfacing with bipolar analog front-ends without level shifting.
Output flexibility and noise immunity
The output stage supports CMOS, push-pull, rail-to-rail, and TTL logic levels, so the same comparator can drive a microcontroller GPIO, a logic gate input, or a relay driver without an external pull-up resistor. The ±2.5 mV internal hysteresis prevents oscillation on slow-moving input signals — no external positive feedback network is needed for clean switching. Common-mode rejection ratio (CMRR) and power-supply rejection ratio (PSRR) are both 80 dB typical, meaning supply ripple and common-mode shifts couple weakly to the output decision. In a noisy industrial 24 V backplane stepped down to 3.3 V, the comparator's decision threshold stays stable within a few millivolts.