Hello,
I am trying to use the TPS65150 to create 10V, -14V, and 18V all from one power supply using a 1.8V VIN. I have attached my schematic below. I followed the datasheet and SLVA794.pdf to create a double stage for the negative charge pump.
The power supplies come up, but not to the correct level. The boost converter comes up to 7.4V, and negative charge pump comes up to -11V, and the positive charge pump comes up to 14.5V.
I measured the part's internal Vref on pin 1 as 0.855 V, which should be around 1.2V according to the datasheet.
Do you have any suggestions for why Vref is not reaching the specified level? I suspect the low Vref is causing the rest of the supplies to be too low.
Thanks for the help!7752.TPS65150_schematic.pdf