Other Parts Discussed in Thread: TPS61291
Three separate questions:
1) Is there any time delay from the time the EN pin is taken low to the time the bypass switch is engaged? I am concerned about the energy from the output capacitors back-feeding into the coin-cell battery that I am feeding this system with.
2) Is there a way to implement a soft-start on this part? My load is only 10mA, and I want to run from a lithium coin-cell. I don't want to add huge capactiors as their leakage current at high temperatures actually surpasses the shut-down current of the switcher.
3) The VIH rating on the datasheet seems incorrect. Normally the active-high voltage levels for a digital pin are specified as a minimum and maximum required voltage where the maximum voltage would be the absolute worst case required to turn the part on. For this part the max is listed as VIN+1 volt. So this tells me that with a 2.5 volt battery feeding a 3.3V system, I can't actually guarantee that the EN pin can be activated high (it would require a worst case of 3.5V). I hope this is just a typo? Since I am running an MSP430 processor from a coin-cell with this part, the voltage available to enable the switcher is only equal to the coin cell (which could be as low as 2 volts).
Thanks!