Replicating the Power LED?

userHead anlumo 2018-12-05 10:43:40 2653 Views3 Replies
Hi,

Can you explain the functionality of the S0/S3/S4/S5 pins? S0 seems always to be at 5V, while the others are at 0V when the device is powered down and at 5V otherwise.

I'd like to move the power LED signalling to the outside of my case, but I can't find any pin that does the same as this LED (with blinking etc). According to the documentation, the S0 pin should indicate the powered up state, but it seems that this is always high no matter what. I could use the S3 pin to at least indicate powered up/down state, but it feels weird to use the sleep indicator for this.

Further, what's the internal connection of these pins? Are they just connected via a highside MOSFET to the 5V regulator, so I can draw some current from them, or should I use a MOSFET of my own to drive an LED? Is there some current limiting happening?