Hi, folks,
1) ESD Ratings
I am considering using the TPS2557 to accept power from an external charger, so the TPS2557 IN pins will be exposed to ESD. The data sheet implies that the TPS2557 is used to deliver power to external devices, in which cases the OUT pins will be exposed to ESD. To which of the TPS2557's 8 pins + PAD do its ESD ratings apply?
2) Soft Start
I just want to apply power by plugging in a USB cable, no enable feature. So I want to simply tie the TPS2557's EN pin high. If simply tie the TPS2557 EN (enable) pin high, will the soft start feature activate when power is applied, or must EN input be toggled ON after power stabilizes?
3) Thermal Model
What PCB configuration is assumed for RΘJA (Junction-to-ambient thermal resistance) = 41.5 °C? The data sheet doesn't say. It refers to T.I.'s general app note, SPRA953C, which doens't list the TPS2557's DRB package.
- Bill
