Dual-rail supervisor with 70 ms reset timeout
The Texas Instruments TPS3306-15DR is a multi-voltage supervisor that monitors two independent supply rails with thresholds at 1.4 V and 2.93 V. It asserts a reset output (active low, open-drain) when either monitored voltage falls below its threshold, and holds reset low for a minimum of 70 ms after both rails return above threshold.
Reset behaviour and output type
The reset output is active low and open-drain, so it can be wire-ORed with other reset sources on the board. The 70 ms minimum reset timeout gives downstream logic and FPGAs enough time to stabilise after power-up before the reset is released.