Other Parts Discussed in Thread: TPS25810-Q1
In the datasheet for the TPS25810-Q1 is says to connect REF to REF_RTN with a 100k 1% resistor. In the layout guidelines it even lists some specifics:
The resistor attached to the REF pin of the device has several requirements:
- It is recommended to use a 1% 100-kΩ low-temperature-cocoefficient resistor.
- It should be connected to the REF and REF_RTN pins (pins 9 and pin 10, respectively).
- The REF_RTN pin should be isolated from the GND plane. See Figure 29.
- The trace routing between the REF and REF_RTN pins of the device should be as short as possible to reduce parasitic effects on current-limit and current-advertisement accuracy. These traces should not have any coupling to switching signals on the board
In the reference design schematic they list pin 9 as a ground pin and appear to treat it as just another pin. Further reading of the datasheet does state that REF_RTN is internally connected to ground but I think this schematic is not correct and could be overlooked by people reviewing it.
