In the Rev C4 Schematics, R72 on Page 6, which is connected to Pin N11
of the TPS65950 is listed as a 12K ohm resistor which is should be.
However, the Beagleboard I have are populated with a 1.2K ohm
resistor. If I am reading the data sheet correctly ADCIN5 has a max
input voltage of 2.5v.
Because there is a 1.2K ohm resistor where there should be a 12K ohm
resistor it looks like you are putting about 4.5 volts on that pin.
What is this effecting?
R72 should be a 12K resistor. It is part of a voltage divider that is used to measure the current consumption of the board by reading the voltage on either side of the resistor. This feature is rarely used as far as I know. It should be a 12K, bu the current BOM calls out 1.2K, so I need to check into that. It will not affect normal operation of the board.
Gerald
The correct values are 1.2K R72 and R73. The correct values are 1K on R73 and R71. We changed the BOM several revisions back but it was missed on the schematic. We determined that we needed to get a little more current into the ADC for proper operation and that was the change. The divider ratio remained unchanged.
I will update the schematic and the SRM for the next round of documentation updates.
Gerald