IC for long time period (up to 24 hours)

[keith1200rs]

I seem to remember some suggestions for an IC to generate long time periods on the forum (for example up to 24 hours) but I cannot find it from the search. I realise you can do it with a small PIC or oscillator and counter, but I am looking for a cheap, single chip solution. Any ideas?

Thanks.

Keith.

 

[barry]

A PIC IS a cheap, single chip solution. A PIC10F200 is US $0.48 in single pieces.

 

[keith1200rs]

I am not sure if this was the device I had seen but it can create times up to 9.5 hours - the LTC6991:

https://www.linear.com/product/LTC6991

It is a bit late for my project (I used a PIC in the end).

Keith

 

[Analog Ground]

The NXP 74HC/HCT5555 has a counter up to 2^24 and only requires an external R and C. The LTC6991 has a 2^21 counter. Timing the 74HC5555 to 24 hours is practical and the RC required is reasonable and within specification. The data sheet has a suitable chart (Figure 13). BTW. This is an old part but still in production.