2.9 V threshold supervisor for automotive power rails
The TPS3840DL29DBVRQ1 is a Texas Instruments simple reset/power-on reset IC from the TPS3840 family, designed to monitor a single voltage rail at a 2.9 V threshold with an active-low, open-drain output.
619 ms timeout — power-up sequencing margin
The typical 619 ms reset timeout period holds the microprocessor in reset long enough for the supply rail to stabilise and the oscillator to start, preventing premature code execution during power-up or brown-out recovery. With an open-drain output, the reset signal can be pulled up to a different voltage rail than the monitored supply, which simplifies level-shifting in multi-voltage automotive designs.
SOT-23-5 package and supply monitoring
Housed in a SOT-23-5 package (SC-74A), the device monitors a single voltage rail — the 2.9 V threshold targets 3.3 V or 3.0 V nominal rails with enough margin to catch a brown-out before the downstream logic fails.