AM437X: RTC power

burak balkuv

Can you provide power consumption of the RTC domain, Looking to size the backup battery.

Current required for time measurement and time maintenance when only RTC domain is supplied from backup battery as Figure 6-4.3.4 at page 60 of spruhl7d

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

You can use the AM437X Power Estimation tool to calculate this: processors.wiki.ti.com/.../AM437x_Power_Estimation_Tool

0 burak balkuv over 8 years ago in reply to Biser Gatchev-XID

Intellectual 620 points

Power estimation Tool does not provide the details needed for RTC only operation. We need to know the current draw to calculate battery capacity during RTC operation.

0 Biser Gatchev-XID over 8 years ago in reply to burak balkuv

TI__Guru**** 393215 points

I have asked if there is any additional data available.

0 kshin over 8 years ago

TI__Genius 16690 points

Please refer to RTC-only power measurements in this wiki.
processors.wiki.ti.com/.../AM335x_Power_Consumption_Summary

0 burak balkuv over 8 years ago in reply to kshin

Intellectual 620 points

While the AM335x power data is helpful, it has some datapoints that are confusing.
In RTC mode only there us Current for the MPU and Core recorded. MPU current is 150uA and fairly significant.
Is this a typo? There is no Voltage applied to MPU and the Core rails?

0 burak balkuv over 8 years ago in reply to burak balkuv

Intellectual 620 points

When can i expect an answer?

0 kshin over 8 years ago in reply to burak balkuv

TI__Genius 16690 points

There is no voltage applies to power supplies other than VDDS_RTC. The power was measured by using current shunt resistors with precision DMM. Since the value of the current shunt resistors for VDD_MPU and VDD_CORE is optimized for much higher current than other rails. The 150 uA is in the range of measurement errors.

0 Mohsen Khayami over 7 years ago in reply to kshin

TI__Mastermind 22391 points

I assume the RTC numbers in the AM335 also applies to AM437? If not then we need the numbers for the AM437 RTC please.

Thanks

Regards
MK

0 Mukul Bhatnagar over 7 years ago in reply to Mohsen Khayami

TI__Guru* 78285 points

Mohsen
See if this helps
processors.wiki.ti.com/.../Processor_SDK_Linux_Kernel_Performance_Guide

This is the upgraded format , hopefully more readable.
If more guidance is needed on RTC power , let us know.

Regards
Mukul

0 Mohsen Khayami over 7 years ago in reply to Mukul Bhatnagar

TI__Mastermind 22391 points

Mukul

thanks that is exactly what i needed.

Mohsen

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AM437X: RTC power