I'm attempting to prototype a boosting power supply based on the TPS55340. The issue I'm having is that the whole system seems to have a voltage gain of one: the output voltage is not boosted beyond the input, i.e. the inductor is behaving like short. This leads me to believe that the chip is not switching as it should.
I've tried ramping up the feedback network to force greater gain in the error amplifier, but no change. I've moved caps around, swapped cap dielectrics and chemistries, used higher precision resistors, triple checked connections, and swapped ICs. All attempts had no effect.
I'm beginning to think that either I'm just missing something simple, or this chip simply an't be prototyped without fabricating a PCB first.
The circuit is built on a prototyping board (not a PCB). I'm aware that the layout of switching converters is quite important, and I've done my best to follow what I know to be best practices (components close to pins, small traces, etc.) however I do not know if this is enough. In the past I've been able to build buck-boost converters on a proto-board before ordering a PCB, but these were not TI chips.
I did the design calculations by hand, but they match almost exactly with the component values I get from the excel design helper:
So: can anybody think of what I might be doing wrong, based on my symptoms?