2.64V threshold — what it means for a 3.3V rail
The 2.64V threshold is set to detect an undervoltage condition on a nominal 3.3V supply before the downstream logic enters an indeterminate state. At 2.64V, the supervisor asserts reset with a guaranteed minimum 120ms timeout, giving the supply time to recover or the system time for an orderly shutdown. For a 3.3V rail with ±5% tolerance, the lowest valid voltage is 3.135V, so the 2.64V trip point provides roughly 0.5V of margin before the reset fires — adequate for most automotive ECU power designs.
For a tier-one ECU program, the AEC-Q100 cert is the minimum gate — this part clears it without a PPAP waiver.