About the capacitor

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hartingwada
Posts: 18
Joined: 01 Jun 2020, 10:22

About the capacitor

Post by hartingwada »

Dear KUNBUS

Our customer is concerning about the component colored in light blue in p1 of the power point file.
We are wondering it is one of the capacitors colored in light blue in p2?
Would you please kindly share some detail information with us?
Such as:
What are that component and the two capacitors? And what are they used for? The more detail the better.

Many thanks in advance!
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lukas
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Posts: 186
Joined: 13 Feb 2017, 10:29

Re: About the capacitor

Post by lukas »

That's the supercapacitor powering the RTC. The supercap will sustain the RTC's clock for a couple of hours when the RevPi is not connected to a power supply.
hartingwada
Posts: 18
Joined: 01 Jun 2020, 10:22

Re: About the capacitor

Post by hartingwada »

Thank you for your advice.
Coul you tell me Model name, the product specification?

Best Regards,
Jo Wada
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lukas
Expert
Posts: 186
Joined: 13 Feb 2017, 10:29

Re: About the capacitor

Post by lukas »

Please find the datasheet for the supercap C703 here:
https://pl.mouser.com/datasheet/2/212/1 ... 104096.pdf

The supercap is listed as part number FC0V224ZFTBR24 in Table 1 on Page 4 of the datasheet.

Could you tell us what exactly you need this information for? Are you trying to determine how long the supercap is able to power the RTC? If so, you may find the datasheet disappointing as the self discharge characteristics for the 3.5V variant of the supercap are listed as "not specified" on Page 7.

However one of our hardware engineers is currently performing measurements to determine how long the RTC can be powered. He's found that we can make optimizations to the wiring of the RTC and to its kernel driver to reduce its power consumption and thus improve how long it can be powered by the supercap. We're looking into implementing these optimizations in a future board revision and kernel release.
hartingwada
Posts: 18
Joined: 01 Jun 2020, 10:22

Re: About the capacitor

Post by hartingwada »

Dear Lukas

Thank you for your support.
This is the necessary information for our customer’s export management.


Best Regards,
Jo Wada
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