??? 05/04/07 02:40 Read: times |
#138582 - Round 3 - Hopefully better Responding to: ???'s previous message |
Ok, so lots of changes here based on the information you guys provided.
1) (S-R) latch schematic symbol updated (and more importantly I understand why). 2) As Eric pointed out, power-up is sort of a race condition. Although it's not a big deal in my app, I'm hoping my method would result in an off condition. I'm relying on the RESET input charging up slower than the SET latch. Whatcha think? 3) I've flipped the ON logic to the SET side of the latch. The old circuit I posted was actually from a previous project that used negative on logic. 4) I've removed the option for the microcontroller to force a turn-on. This isn't a feature i want or need. However, I should still be able to drive the latch off by applying a logic zero to FORCEOFF. 5) Similarlly to Michael's circuit, I now have a on\off button press detection and as such should be able to react accordingly (special modes or powering the device off). Looking for any other ideas or suggestions. I certainly could have misunderstood something so any help is appreciated. Bruce |