PCF8563 coin cell backup with diode

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PCF8563 coin cell backup with diode

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prottoy_credosense
Contributor I

The RTC does not work properly in this scenario (interrupts are not occurring, clock resetting, MCU is being powered via the CR1025 battery).

 

See not_working.png

 It works fine if I use two separate batteries like below:

 

see working.png

Is the design flawed? I want to run the RTC if any one of the batteries is present or use a supercapacitor instead of the CR1025 as a backup.

 

Thank you

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3 Replies

964 Views
guoweisun
NXP TechSupport
NXP TechSupport

Please series in resistor around 300OHM between battery and diode and try to test again.

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990 Views
guoweisun
NXP TechSupport
NXP TechSupport

Some wrong about open your pictures,could you please attached them again?

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973 Views
prottoy_credosense
Contributor I

@guoweisun I uploaded the images again.

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