What the 1.62V threshold means for your 1.8V rail
The TPS3124J18DBVT monitors a single voltage rail and asserts reset when the supply drops below 1.62V. For a nominal 1.8V core supply, that threshold trips at roughly 90% of nominal — early enough to catch a brownout before the processor logic corrupts, but not so early that normal ripple triggers false resets. The reset output is both Active High and Active Low, driven by a push-pull totem-pole stage. That means one chip can drive a microcontroller's active-low reset pin and simultaneously enable a peripheral that needs a high level during reset, without an external inverter or pull-up resistor.
Reset timeout and temperature range
That 100ms floor is a datasheet minimum; actual timeout may be longer, but the processor sees a clean release. The SOT-23-5 package keeps the footprint small, but the 0.95mm pitch means standard FR-4 with 0.5mm traces routes comfortably.
The base product number is TPS3124, and the J18 suffix denotes the 1.62V threshold variant. ROHS3 compliant.