AM5746: VDD_RTC connection

Koichiro Tashiro

Part Number: AM5746

Hi,

I have a question for IDK574x VDD_RTC connection.
According to user’s guide (spruij9a.pdf) figure 6, VDD_RTC is connected to PMIC LDO9 output.
But in the schematics VDD_RTC is connected to VDD_CORE.
Why?

Thanks and regards,
Koichiro Tashiro

over 5 years ago

0 Biser Gatchev-XID over 5 years ago

TI__Guru**** 393215 points

Hi,

Please refer to section 2.19 in www.ti.com/.../sprack7b.pdf

0 Koichiro Tashiro over 5 years ago in reply to Biser Gatchev-XID

TI__Mastermind 22935 points

Hi Biser,

I understood our schematic checklist recommends to connect PMIC vdd_core supply to vdd_rtc pin.
Is there any specific reason why we use vdd_core instead of vdd_rtc?
(even PMIC has dedicated LDO output for vdd_rtc)

Thanks and regards,
Koichiro Tashiro

0 Biser Gatchev-XID over 5 years ago in reply to Koichiro Tashiro

TI__Guru**** 393215 points

Yes, VDD_RTC needs to be connected to the dedicated LDO only if RTC mode is used. However RTC mode is not supported on this family of devices, as stated in section 3.1 of the TRM.

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AM5746: VDD_RTC connection