Ultra-low-power comparator with onboard reference in 1 mm²
The MAX9063EBS+TG45 from Analog Devices integrates a single comparator with a voltage reference in a 4-UCSP package measuring just 1.05 mm x 1.05 mm — the reference and comparator share one die, so the threshold is set without external resistors or a separate reference IC.
Built-in hysteresis kills the chatter
±12 mV of internal hysteresis means the comparator does not oscillate near the threshold — an op-amp pressed into comparator service would need external positive feedback to match this, and the MAX9063 already has it on-chip. Propagation delay is 15 µs maximum — fast enough to catch a 33 kHz signal edge cleanly, but not a high-speed pulse train. The open-drain output lets the user pull up to any voltage up to the supply rail, making it straightforward to interface a 1.8 V sensor threshold to a 3.3 V logic input. Input bias current is 60 pA maximum at 3.3 V — negligible for a 10 MΩ sensor divider, where the bias-induced offset stays under 600 µV. Power-supply rejection ratio is 53 dB typical, so a 100 mV ripple on the supply rail shifts the threshold by roughly 0.2 mV — the internal reference tracks supply changes well enough that the trip point stays stable without a separate LDO.