Comparators compare two input voltages and output a digital-level signal, commonly used for threshold detection, over/under-voltage protection and signal-shaping circuits.
How to read the key parameters:
- Propagation delay (tpd): The lineup spans a wide 73ns to 5600ns. Low-tpd parts respond fast, suiting delay-sensitive uses like fast overcurrent protection and signal shaping; high-tpd parts trade response speed for very low power, suiting slow-changing detection like battery-voltage monitoring.
- Quiescent current (Iq, per channel): The lineup covers roughly 0.418μA to 900μA per channel, trading off clearly against tpd — the 0.418μA tier corresponds to a slow 5600ns response, while the 160μA tier already reaches a fast 73ns response; balance power budget against speed need, and for multi-channel parts scale this per-channel figure by channel count to get total device current.
- Hysteresis: Some parts build in roughly 3~3.5mV of hysteresis; others list none. Parts with hysteresis resist repeated toggling when the signal crosses the threshold slowly or in noisy conditions, suiting noisy environments; parts without hysteresis respond more "cleanly" but need an external hysteresis network.
- Offset voltage (VOS): The lineup covers 3.5mV to 5mV, setting the floor on threshold-decision accuracy — precision threshold detection should use a low-VOS tier.
- Supply voltage: Wide-voltage parts at 2~36V connect directly to industrial supplies; low-voltage parts at 2.5~5.5V suit battery/low-voltage systems.
Three steps to select:
- Set the tpd ceiling by required response speed, then check whether per-channel Iq times channel count fits the power budget.
- Judge whether the signal environment has noise or slow transition edges to decide if built-in hysteresis is needed.
- Finalize the part and channel count by supply-voltage range; separately verify the output stage type (e.g. push-pull vs. open-drain) against the downstream circuit — this isn't among this category's filterable fields, so check the specific part's datasheet.
Common pitfalls:
- Using a no-hysteresis part in a noisy environment without adding an external hysteresis network, causing repeated toggling and false triggers near the threshold.
- Looking only at tpd without checking the matching Iq, over-speccing a low-power always-on monitoring use case into a fast, high-power part.
- Overlooking output-stage type against the downstream circuit (e.g. an open-drain output left without a pull-up resistor won't work) — this isn't covered by this category's filterable fields, so confirm it on the specific part's datasheet.
Filter and compare part numbers by tpd, Iq, hysteresis and supply voltage in our online selector; contact us for support on a specific application.