1.8V threshold supervisor for a single-rail watchdog
The TPS389018DSET is a Texas Instruments Simple Reset/Power-On Reset IC that monitors a single 1.8V supply rail and asserts an active-low reset when the voltage drops below threshold.
6-WSON 1.5x1.5 mm — footprint reality for dense layouts
The 6-WSON package with a 1.5x1.5 mm body is the smallest supervisor package in this threshold class. Without that, the junction-to-board thermal resistance rises and the 125°C limit becomes harder to hold under continuous operation. Surface-mount only, supplied on tape and reel. The 6-WFDFN package variant is the same footprint as the WSON — confirm the exact supplier device package code 6-WSON (1.5x1.5) when ordering the land pattern.
Cross-shop note vs TLV803 family
The TLV803EA29VDBZR and TLV803ED29DBZR are the closest functional peers — both are active-low, open-drain supervisors with a single monitored rail. If your system needs a known delay before the reset de-asserts, the TLV803 variants guarantee that window; the TPS389018DSET is chosen when the timeout is handled elsewhere or when the 1.8V threshold is the hard requirement.