Hi all
I have an odd issue with a design using a TI TPS63000 buck/boost controller; it is set up to give an output voltage of 3.6V.
When applying power (4.1V limited to 100mA in this case) with the enable pin low all is well, but when I enable the device with a 3.3V 'enable' signal the bench supply goes into CC mode as this part is trying to pull >100mA.
I'm a bit stumped as I've used the fixed voltage variant of this part in the past with no problems, and in this example have isolated all circuitry that is powered by this device.
The waveform is pretty ugly; the VBAT net is in yellow (i.e. the device's input, set to 4.1V and limited to 100mA from my bench supply), and the output is in blue. Note that for this test I tied the device's enable pin to the VINA and PS/SYNC pins as per the datasheet's example.
Have I missed something obvious?!
(By the way, the schematic shows the TPS63001, but the correct part (TPS63000) is indeed fitted)