Supervising a single 2.5V rail with a fixed threshold
The TPS3840PL25DBVR is a Texas Instruments single-channel power supply monitor that asserts a reset output when the monitored voltage drops below 2.5V. Its push-pull, totem-pole output drives the reset line high or low without an external pull-up resistor, simplifying the BOM on a processor or FPGA power-good chain. The 619 ms typical reset timeout holds the system in reset long enough for the supply to stabilise after a brown-out or power-up, matching the startup sequencing needs of many Cortex-M and low-power MCUs.
Sizing the timeout and temperature envelope
The 2.5V threshold is fixed, so the BOM must match the exact rail being monitored — no resistor-divider adjustment. Compared to the TLV803EA29VDBZR (active-low, open-drain output, 130 ms min timeout), this part offers a push-pull output and a longer, fixed 619 ms timeout. The open-drain sibling requires an external pull-up; the TPS3840PL25DBVR does not, saving one resistor per channel.
Active production with ROHS3 compliance
The SOT-23-5 package (SC-74A) is a common footprint with broad second-source potential. The base product number TPS3840 covers multiple threshold voltages; confirm the 2.5V variant when ordering.
