I need to build a timer capable of activating an output high signal in the voltage range of 3 to 5v, but I'd like it to consume as little power as possible, something in the range of less than 100 uA. Timing range should be adjustable between 30 minutes and 4 hours, which will start counting as soon as the device is turned on. Timing precision can be in the range of 5 to 30 seconds, so it's really not critical.
For this application, it's pretty obvious to me that an ordinary 555 is simply out of the question.
Where should I start?
For this application, it's pretty obvious to me that an ordinary 555 is simply out of the question.
Where should I start?