Power consumption with CyPmSleep(PM_SLEEP_TIME_NONE, PM_SLEEP_SRC_PICU) unexpected high

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KrDe_284951
Level 4
Level 4
10 replies posted 10 questions asked 5 replies posted

Hi,

We have an application on Cy8C3246 using following code snippet to enter sleep mode:

CyPmSaveClocks();

CyPmSleep(PM_SLEEP_TIME_NONE, PM_SLEEP_SRC_ONE_PPS);

CyPmRestoreClocks();

During sleep our entire system draws a current of approx 4µA.

To further reduce power consuption (mainy by waking up the PSoC only when required by an external device), we want to use following construction:

CyPmSaveClocks();

CyPmSleep(PM_SLEEP_TIME_NONE, PM_SLEEP_SRC_PICU);

CyPmRestoreClocks();

where an external component wakes the PSoC every minute (in stead of every second)

However the current drawn by the enire system during sleep is now appox 25µA.

What causes this increment in current and how can it be prevented? The only alteration we made to the code is the replacement of the wakeup parameter.

(Note CyPmHibernate() is not useful to us, since this leaves he io pins floating)

Thanks,

Krs

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1 Solution
Rakshith
Moderator
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250 likes received 1000 replies posted 750 replies posted

Hi KrDe_284951,

Just an update to my previous response. I tried a simple sleep project with wake source set to the switch on the PSoC 3 Development Kit.

I was able to get a current measurement of 1 uA after following all the steps mentioned in Section 4.2.1.3 Low-Power Functionality in PSoC® 3 Development Kit Guide. I have attached the project for your reference.

So, the excess current in your setup might be because of the external component itself. Please let me know if disconnecting the external component helped solve your issue.

Thanks and Regards,

Rakshith M B

Thanks and Regards,
Rakshith M B

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3 Replies
Rakshith
Moderator
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250 likes received 1000 replies posted 750 replies posted

Hi KrDe_284951​,

I will be measuring the sleep current using a PSoC 3 Development Kit from my end and see if I can reproduce the issue. Meanwhile, please let me know how you are measuring the sleep current. Can you try disconnecting the external component and then measuring the sleep current?

Also, please share your project.

Thanks and Regards,

Rakshith M B

Thanks and Regards,
Rakshith M B
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Rakshith
Moderator
Moderator
Moderator
250 likes received 1000 replies posted 750 replies posted

Hi KrDe_284951,

Just an update to my previous response. I tried a simple sleep project with wake source set to the switch on the PSoC 3 Development Kit.

I was able to get a current measurement of 1 uA after following all the steps mentioned in Section 4.2.1.3 Low-Power Functionality in PSoC® 3 Development Kit Guide. I have attached the project for your reference.

So, the excess current in your setup might be because of the external component itself. Please let me know if disconnecting the external component helped solve your issue.

Thanks and Regards,

Rakshith M B

Thanks and Regards,
Rakshith M B
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Hi Rakshith,

Thanks for pointing this out. I removed all components from the PCB and current consumption was back to expected level. It seems I left  one hardware component uninitialized, causing the trouble. Now I have follong results:

- deep sleep mode with 1 pps wakeup: < 4 µA (during sleep)

- hibernate < 1µA

Thanks for your concern

Kris

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