Quad comparator with a built-in voltage reference — one chip replaces four
The Maxim Integrated MAX934CSE+ packs four independent comparators and a precision 1.182V voltage reference into a single 16-SOIC package. That reference is the differentiator versus a plain quad comparator like the LM339 — it saves you an external reference IC, two bypass caps, and the PCB real estate they'd occupy. Typical applications include battery-powered threshold detectors, window comparators, and 0°C to 70°C commercial-grade supervisory circuits where board space and quiescent current are the constraints.
12 µs propagation delay — slow by modern standards, deliberate by design
The 12 µs max propagation delay is not a speed demon — you wouldn't use this for switching-regulator feedback or high-speed zero-crossing detection. But that delay is the direct result of the 8.5 µA max quiescent current across all four comparators plus the reference. For line-frequency (50/60 Hz) monitoring, over-temperature sensing with a thermistor, or battery undervoltage lockout, 12 µs is plenty fast, and the sub-10 µA total draw is what makes it viable for always-on monitoring in portable gear.
2.5V to 11V supply — fits 3.3V and 5V rails without a regulator
The supply range spans 2.5V to 11V single supply, or ±1.25V to ±5.5V dual supply. That means it runs directly off a 3.3V or 5V logic rail without an extra LDO. The CMOS/TTL output stage swings rail-to-rail, so it drives logic inputs cleanly at either voltage. Input offset voltage is specified at 10 mV max at 5V — adequate for threshold detection where the trip point has several hundred millivolts of hysteresis.
80 dB CMRR and PSRR — noise rejection for dirty environments
Typical common-mode and power-supply rejection ratios are both 80 dB. That matters when the comparator shares a board with a switching regulator or motor driver: the 80 dB PSRR means supply ripple at 100 mV peak-to-peak translates to roughly 10 µV of input-referred error — negligible for a 10 mV offset comparator. The 80 dB CMRR keeps the threshold accurate even when the input signal rides on a noisy ground plane.
Active production — no end-of-life concern for new builds
The MAX934CSE+ carries an Active product status and is ROHS3 compliant.