Active supervisor — 1.52V threshold on a 1.8V rail
The TPS3839E16DQNT: That 1.52V threshold sits right for a 1.8V nominal rail — it trips before the downstream logic enters an undefined state, then holds the reset long enough for the core supply to stabilise before the processor starts fetching code. The output is push-pull, totem pole, so no external pull-up resistor is needed — it drives the reset line directly.
Package and rework — 4-X2SON 1x1mm
That is a tiny land pattern — the exposed pad underneath is the main thermal path, and the four peripheral pads are small. On a rework station you will want a fine-tip iron and a hot-air pencil set around 300°C; the pad pitch is tight enough that solder bridges between adjacent pins are easy to make if the flux is heavy. The package is surface-mount and ships in tape and reel or cut tape.
Active production — no LTB, no successor on record
Sourced to order against an RFQ; availability confirmed at quote time.