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Help Selecting Timer

Sam Nelson76005
Prodigy 10 points
Other Parts Discussed in Thread: SE555

Hello,

I need a timer capable of accurate timing to 3 months (= 90days = 7,776,000s), at which time it will then trigger an external event through a FET (or similar). The timing will begin when the timer senses a loss of main power. The 3 month timing duration will then be ran off battery power. In addition to this, the timer needs reset capability and manual override input. The manual override will be provided to the timer via a signal processed by a RF chip.

I am looking for accuracy, simplicity, reliability, low power consumption, and hopefully an internal frequency generation.

I am considering a few options and need help sorting them out.

Option 1: Timer combined with a counter/comparator

Option 2: Clock combined with a comparator

Option 3: MCU

Are there TI products that can be provided for each of the above options? Are there other, better, options?

Thanks!!!

  • 0
    TI__Intellectual 1020 points

    As far as I found,

     

    Option 1: Our timers may be one of the simpler solutions, I would suggest you take a look at our SE555. The issue with this solution is that it may be off by as much as 32hr(1.5%), depending how you plan to apply it and how stable your circuit/supply are.

    Option 2: Our clocks would give you much more accurate timing, but would be inherently more complicated to implement. You could look at our CDCM6100 clocks, which includes some of the options you're looking for. I'm unsure how well this option will run off battery power for three months however.

    Option 3: I would suggest one of our MSP430's. Ultra low power and all the functionality you'll need for your design.

     

    If you're timing isn't as stringent I would suggest option 1, otherwise option 3 I find would be the easier of the two remaining.

     

    Regards,

    Robert Regojo.