The design note introduces a solution for multiple power supplies to ramp up simultaneously to avoid damaging sensitive components. The solution uses N-channel MOSFETs to turn on the power supplies at the same time.
Modern circuits often require multiple power supplies to turn on in a specific order to prevent damage to sensitive components. This document presents a solution for ramping up to five supplies simultaneously using an N-channel MOSFET between the supply output and the load, monitored by the LTC1728-1.8 Hot Swap controller.
The solution is designed for up to five supplies ramping up at the same time.
The device directly monitors three supply outputs: 5V, 1.8V and 1.5V.
The open-drain pull-down turns off after a 200ms delay.