2.9V threshold monitor with 40µs reset timeout
The TPS3899DL29DSER is a single-channel voltage monitor from Texas Instruments with a fixed 2.9V threshold — the trip point is set internally, no external resistor divider needed. When the monitored rail drops below 2.9V, the open-drain output pulls low and stays asserted for a typical 40µs after the rail recovers, then releases. That 40µs timeout is short enough to avoid holding a processor in reset through a brief brownout, but long enough to debounce a glitch on a noisy supply.
Open-drain output and temperature range
The open-drain output (active-low) lets you pull up the reset line to any voltage the downstream logic needs — 1.8V, 3.3V, or 5V — without a level shifter.
For BOM planning, this is a low-risk line — no imminent obsolescence to budget for.
