The MAX9646EBS+TG45 is a single general-purpose comparator from Maxim Integrated, built for low-power threshold detection in battery-operated or portable gear. It draws a maximum quiescent current of 1.1µA, so it won't drain the cell in always-on sensing roles like overvoltage lockout or battery monitor. Supply range runs from 1V up to 5.5V, covering single-cell Li-Ion through 3.3V and 5V rails without a secondary regulator. With a 15µs maximum propagation delay, this part is fast enough for power-good sequencing and window comparators but not for high-speed ADC front ends.
Package reality — the 4-UCSP footprint
This part comes in a 4-WFBGA, CSPBGA package — a 4-bump wafer-level chip-scale package measuring 1.05mm x 1.05mm (supplier device package 4-UCSP).