I have a new design using the TPS65261 regulator and I am having issues getting the automatic power sequencing to work. Initially I have it setup for the automatic power sequence mode however the part fails to start switching in this setup. The EN pins are tied to VIN through resistor dividers setting them at 2V and GND respectively (EN1,3=high and EN2=low) and the mode pin is tied to V7V through a 0ohm resistor. VDIV is pulled high by a resistor divider from VIN to around 3V. I see the V7V output go high and the boot pins of the regulators turn on. However, the SS pins are all holding at 0V (each is just tied directly to a cap) and the LX outputs are all holding at ~0V (although it is a very noisy "GND" in this state).
Is there some special sequencing on the EN, DIV or MODE pins to enable the automatic power sequencing?
When I disable the automatic mode (MODE=GND) and just tie each EN pin to separate capacitors to GND, the regulators startup just fine. Any ideas? Thank you in advance!
