Scope screenshot of a 1.8V power rail coming up from the off state, stabilizing, then turning off after 5ms

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   Andrew Zonenberg (azonenberg@ioc.exchange)'s status on Wednesday, 27-Mar-2024 03:36:10 JST Andrew Zonenberg

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   Starting to bring up power rails. As usual for my recent prototypes there's a microcontroller that has all of the EN/PGOOD signals and controls all of the rail sequencing.

   12V0 came up fine and measures 11.988V, perfectly normal.

   The (unswitched) 5V0 analog rail came up fine, measuring 5.0371V.

   The first switched rail was 1V0, measuring 0.99195V. Also fine.

   1V8 is where it gets interesting. The rail comes up just fine and seems to stabilize, but PGOOD never goes high (or at least, the supervisor doesn't think it does). So it panics, thinking that there's a short on the rail, and e-stops every power rail on the board.