Other Parts Discussed in Thread: TPS61099
While testing the TPS61220EVM-319 I ran in the following issues:
1. When I pull the EN-Pin to GND, the board still puts out ~0.9V on VOUT. I'd espcet to see 0V. The Eval board went through some testing, I'm afraid that this is an indicator for a dmaged board. Before changing the device, I just want to be sure this is neither a feature nor a known bug.
2. When we drive our system (sourced by 1.2V Bat voltage) the inrush current causes a drop on the battery resistance and input voltage for the boost-converter drops below its specified values. Causing the regulator to draw high currents and therefor maintaining this "catastropic" state (bad efficiencies etc. included). This can be worked around with buffer capacitors and an additional switch for the output voltage. However I was wondering if there is a smarter solution, e.g. with a softer ramp up of the output voltage...
It seems like this is a rather common problem of converters: cutting their own voltage due to parasitc input resistance.
Any help is appreciated.