What the 2.7V threshold means for your rail
The ADM6320CZ27ARJZ-R7: The 2.7V threshold is a common trip point for monitoring 3.0V or 3.3V rails — it catches a brownout before the downstream logic (MCU, FPGA, or memory) enters an undefined state. The 140ms timeout gives the core supply time to stabilize before the processor is released from reset, which is long enough for most bulk-capacitor charge times on a typical board.
The open-drain output means the reset line requires an external pull-up resistor to the logic supply voltage; the pinout is standard for this family, so a layout already using an ADM6320CX29ARJZ-R7 or similar will accept this part without a board spin.