AEC-Q100 grade-1 supervisor for 3.3V ECU rails
It monitors a single 3.3V supply rail and asserts an active-low reset when the voltage drops below the 2.93V threshold, holding the reset for a minimum of 120ms after the supply recovers. The push-pull totem-pole output drives the reset line directly without an external pull-up resistor, saving one component per ECU.
2.93V threshold — the brown-out line for 3.3V logic
The 2.93V threshold is set for nominal 3.3V rails. When the supply sags below this level — during a crank pulse, load dump transient, or regulator dropout — the reset output goes low and stays low until the rail has been above the threshold for the full 120ms timeout. This prevents the MCU from executing on a marginal supply. The 120ms minimum reset timeout gives the main supply regulator and the MCU oscillator sufficient settling time before the processor begins code execution. In designs with a slow-start regulator or a crystal oscillator with a long start-up time, this timeout avoids spurious early-release resets.
SOT-23-5 footprint and supply current
Housed in a SOT-23-5 package (SC-74A, SOT-753), the device occupies minimal board area and routes easily on two-layer automotive PCBs.
For new ECU designs or ongoing production, this eliminates the last-time-buy risk that obsolete supervisors introduce.