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Tool/software:
Hi,
Could you provide reference design to get trigger signal after 8 hours?
MCU will give the signal to timer and timer will provide trigger signal after 8 hours.
Please provide the design and let me know the tolerance.
Thanks.
Hello David,
That is an monostable timer. See application note ;[FAQ] How do I design monostable timer circuits using LMC555, TLC555, LM555, NA555, NE555, SA555, or SE555? - Clock & timing forum - Clock & timing - TI E2E support forums
It suggests nano timers, https://www.ti.com/clocks-timing/real-time-clocks-timers/products.html#2192=Programmable%20delay%20range&
They can run up to 2 hours. After that use a logic divide by 4.
Hello. Ron Michallick
I am Mr. Jeong.
TPL5000 and TPL5100 have different optional timer intervals
Set a long time (approximately 8 hours) What will work in your favor when using the timer
I would like to make an inquiry.
Thank you.
Hello Mr. Jeong,
I believe TPL5010 set to 2 hours using 170k resistor is the best choice. In 8 hours there should be 4 wake signals if done signal is provided back to the IC or 5 reset signals if started by 'reset' in high and done input is is always low. 5 seems easier to setup
So 5 resets including the one that happens when you start the timer means 8 hours has passed. A counter like SN74LV163A can turn 5 clocks into one ROC pin (done) signal.
I'm transferring this thread to TPL5010 support. Once the number of output pulses is decided, then logic team can suggest the best option.
Hello. Ron Michallick
Thank you very much.
Is there a reference circuit diagram that I can refer to with SN74LV163A?
Please check.
Thank you.
Mr. Jeong,
If the goal of the 8 hours is to reduce battery consumption and this is a CPU based circuit, then it may be best to omit the SN74LV163A (I only know max ICC is 20uA, I don't know the typical) and let the CPU count the 2 hours wakeup (or power up) events. Three of four will immediately go back to sleep or unpowered (in this case the count has to be nonvolatile).
Once the TPL5010 team confirms the TPL5010 is correct or reports an alternative solution or the final count, then I can help finalize the logic divider.
Hello. Ron Michallick
The reason for setting the timer for 8 hours is that after the occurrence of a random event 8 hours
I'd like to make it happen.
It has nothing to do with battery power savings.
For example, the timer receives an event signal from the CPU, and after about eight hours, the timer will perform a certain action
Timer time setting is required to do so.
When an operation is completed for eight hours, the CPU receives an event signal again and then proceeds with an arbitrary operation after eight hours.
Please give me a confirmation.
Thank you.
Mr. Jeong,
TPL5010 and shift register SN74HCS164 is my solution. This is the end of this thread.
Please see this thread for my final suggested solution and any possible TPL5010 updates. https://e2e.ti.com/support/clock-timing-group/clock-and-timing/f/clock-timing-forum/1428431/tpl5010-will-this-give-an-8-hour-delays
If you need more assistance with SN74HCS164, "ask a related question" in the new thread above using SN74HCS164 as a part number.
I wish you luck, this is as far as I can take you.
Just today, I updated the e2e monostable FAQ as seen below...
Due to the large capacitance needed for long pulse time, a nano-timer can be used as an alternative. They only require a single resistor to set the time delay up to 2 hours and use very little power. For even longer time up to 22 hours, CD74HC4060 has an internal oscillator that runs down to 0.1Hz followed by a 14 stage ripple counter. For almost any longer time including hundreds of years, consider 555 astable coupled to SN74LV8154 32 bit counter.