The Texas Instruments TPS3305-25DR is a multi-voltage supervisor that monitors two supply rails with thresholds of 2.25V and 2.93V, covering common 2.5V and 3.3V logic and memory voltage domains. It asserts a reset signal — available in both active-high and active-low polarities — when either monitored voltage drops below its threshold, and holds reset for a minimum of 140ms after both rails recover.
Thresholds and reset timing for processor sequencing
The 2.93V threshold monitors a nominal 3.3V rail, while the 2.25V threshold monitors a 2.5V rail — together they cover the core and I/O supplies common on mixed-voltage boards with FPGAs, DSPs, or dual-supply MCUs. The 140ms minimum reset timeout gives the downstream processor time to stabilize its internal oscillators and PLLs before the reset de-asserts. Both push-pull outputs source and sink current directly, so no external pull-up resistor is needed on the active-low output, and the active-high output drives a logic high without a pull-up. The totem-pole stage handles capacitive loads on the reset line without extra buffering.