5V, 3V3, & 1V2 rails down

sfuphantom / hardware

schematics and layout work

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5V, 3V3, & 1V2 rails down #46

Closed gabesoares closed 6 years ago

gabesoares commented 6 years ago

Fix the broken power rails on the VCU. Something looks like it is wrong with the 5V OR-ing controller as it is burning hot when on. Board now draws 140mA from power supply with 5V, 3V3, and 1V2 rails down. Previously drew 60-80mA under normal operation.

gabesoares commented 6 years ago

Seem to be related to CAN transceivers... both seemed to be drawing too much current on 5V rail. This is the second time the CAN transceiver has been the culprit for a 5V rail drop.

Double check schematic connections and IC.

gabesoares commented 6 years ago

Looks like the schematic connection is wrong, connected VSS to 5V and VDD to GND. Should be the other way around.. This explains why whenever the CAN transceivers are soldered the 5V rail gets messed up. Need to rework the board by cutting some traces and jumping them to switch VSS and VDD.

gabesoares commented 5 years ago

Fixed in rev1, in vcu-hw repo commit 7288ddc6