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Nanotimer with 12 hours duty cycle for power saving

Intellectual 440 points

Replies: 6

Views: 98

I'm still pretty new to electronics so please bear with me.

I need to make an ultra low-power circuit that should provide power to the next stage for ~12 hours and remove power for the rest 12 hours (to save battery). I found TL5xxx nano timers (TPL5111 for example) which are user for power saving. But their maximum timing interval is just 2 hours. So my understanding is the max duty cycle is 2 hours which is not enough).

Since I've never done such a thing please give me an idea on what to use for such a circuit.

Also, I need to set a starting point - at what moment the duty cycles start daily. It could be just pressing a button or pre-programming time or ...anything.

Thank you.

  • I found SN74HC4060 binary counter and its Icc = 80uA @ 6V. I will need the circuit to work from 3.7V. So I suppose supply current will still be way higher than when using nano timers.

    Another option is to use SN74LV163A binary counter and SN74AUP1G08 AND gate (to count 6 times x 2 hours). This combination supposedly would have Icc about 11uA.

    Well, that's what I understand reading datasheets...

    Also, can I use nano timer as clock for SN74HC4060 binary counter? In this case it would count 2 hours cycles... Is this how it works?

  • In reply to Alex Beloff:

    Hi Alex,

    You are correct that the TPL5111 has a maximum time interval of 7200 seconds. You'll need to find a way other than using a single TPL5111 to reach the 12hr duty cycle you want.  

    Do you have any other parts of your design chosen? Could you also elaborate more on what you intend for your circuit to do? This information can help us determine a solution.

    For those two other options you posted, it would be a good idea to submit an E2E post to the Logic Forum. They should have a better understanding for those applications.

    Regards,

    Adam Siismets

  • In reply to Adam Siismets:

    Hi!

    I figured a more flexible would be to use MSP430FR2000 MCU because it has RTC and can be waken up by its interrupt.

    The idea is to just create a module for IoT to save power consumption of the next stage.

    Yes, I did post another related question to Logic forum so I will close this one for now.

    Thank you!

  • In reply to Alex Beloff:

    Good choice, Alex. I'm glad you were able to find help and a solution that works for you. 

    If you did want to read a little bit more about the TPL5111 though, there are some good technical articles related to the topic of low power consumption for IoT applications. 

  • In reply to Adam Siismets:

    No, I haven't. But the link is broken.

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