kirk...@pdx.edu (I) writes: > 1) Aren't the N-FETs upside down?
ARGH! Yes. Thank you for spotting that. > 2) I haven't looked up the gate charge on the FETs About 2.2 nC at our operating point. > I like to use a resistor between the uC and the FET gate (keep > pulldown on uC side). It limits the current draw on the pin, controls > rise time, cuts ground bounce, yada yada. It may not be necessary > here, as I'm usually driving PWM, and you are (most likely) not; > however, it's cheap insurance to protect the uC output. I don't think it's necessary. But after talking to Keith, we'll add the footprints. We've got the space and I've got to rework that part of the board to fix the D/S swap anyway. > 4) Does anyone know what the LTC1682 or LP2980 does when it sees > reverse voltage on the input? A schottky diode or a PFET might save a > bunch of parts if someone connects the battery backward. I don't know what the regulators are going to do in that circumstance, but I hate to take the voltage drop hit on a 3.7 volt nominal battery system where run time in the post-landing search phase could be important. We mitigate the risk of mis-connection by using the JST standard polarized battery connector for the LiPo cell. Thanks for the feedback! Bdale _______________________________________________ psas-avionics mailing list firstname.lastname@example.org http://lists.psas.pdx.edu/mailman/listinfo/psas-avionics