Tool/software:
Hi,
I designed a custom project using the TPS65400 and based the schematic on the EVM.
At startup, only LP_3V3 is enabled, powering low-power 3.3V circuits, which draw around 100mA-200mA.
Here are my measurements:
- VSYS_9V-15V : 15V
- VDDD : 3.3V
- VDDG = VDDA = 6.3V -> It seems high since it is supposed to be 6.1V according to the datasheet.
- CB1 = CB2 = CB3 = CB4 = 6V
- SW1 = LP_3V3 = 100mV
- SW2 = SW3 = SW3 = 0V
- CE = RST_N = EMSW1 = VDDD = 3.3V
- COMP1 = COMP2 = COMP3 = COMP4 = 0V
I tried removing the 4.7k pull-ups on SDA and SCL to ensure they weren’t pulled down since the LP_3V3 is not enabled. I also tried adding a 47µF capacitor near the VIN pin. My layout seems clean overall, although the capacitors on PVIN are on the bottom layer with signals routed through vias. These are directly under the PVIN pins of the TPS65400. I understand that at high current this might not be ideal, but we're only drawing 100mA-200mA.
I can't find any specific reason for LP_3V3 not starting. I've ordered the EVM for further testing, but I would appreciate any feedback or suggestions regarding my design.
sch : Schematic
Layout : 
