Other Parts Discussed in Thread: , TPS65951
Hi,
We have TPS65910A31 start-up (VRTC related) issue with one more customer.
The TPS65910x is used as a PMIC for AM335x.
Similar to the below posts, few boards are working after reducing the load
on VRTC LDO by changing capacitor value on VRTC pin to 0.1uF.
e2e.ti.com/.../1843272
e2e.ti.com/.../2026890
Out of 30 custom boards 5 are not working even with 0.1uF on VRTC.
During power up the VRTC voltage is very low at 0.8V.
VRTC is connected to VDDS_RTC and RTC_KALDO_ENn as per the reference
document (TPS65910Ax User's Guide for AM335x).
With so many issues related to VRTC start-up, we believe this LDO
should not be used in any use case, even if the load is smaller or not.
Please do let us know if this is a kind of errata in TPS65910A31?
Meanwhile with one of our customer, we have asked them to remove all the
loads from VRTC and connect VDDS_RTC to available LDO like VDAC as shown below.
Could please let us know if this is the proper way to reduce load on VRTC?
And if there is any other recommended design to reduce load on VRTC..
It will be very helpful if you change the reference diagram in the user
guide(SWCU093E) which will show that VRTC should not be used in any application.
Best Regards
Kummi