TPS65910A3A1 VRTC up to 2.5v

The voltage we measured on this board:
VRTC=2.5
VCC1=1.2
VCC2=1.2
VCC3=2.07
VCCIO=0.78
VDIG1=3.8V
VDIG2=3.45
VAUX33=2.09

Hi Gary,

1) Were VCC1,2,3, and VCCIO measurements actually on VDD_MPU, VDD_CORE, VAUX33, and VDDS_DDR? If not, how are you supplying these rails?

2) Is VRTC_PMIC and VRTC bridged or separated?

3) What is the voltage on VREF?

4) If you ground PWRHOLD to turn the device off, does VRTC return to 1.8V?

5) Are you making any register changes to GPIO0_REG in your code?

 

Thanks,

Rick S.

Hi Rick,

   Pls see my input.

1) Were VCC1,2,3, and VCCIO measurements actually on VDD_MPU, VDD_CORE, VAUX33, and VDDS_DDR? If not, how are you supplying these rails?

Gary: Yes. They are measured on VDD_MPU, VDD_CORE,  VAUX33 and VDD_DDR.

2) Is VRTC_PMIC and VRTC bridged or separated?

Gary: It's separated. VRTC is supplied by external LDO.

3) What is the voltage on VREF?

Gary: It's 0.849v.  I also measured TI AM335X starterkit with TPS65910. The VREF is 0.837v.

4) If you ground PWRHOLD to turn the device off, does VRTC return to 1.8V?

Gary. Yes, it return to 1.8v.

5) Are you making any register changes to GPIO0_REG in your code?

Gary: No. 

I found that 5v input will be drawn to around 3.6v after PMIC start up. And the input will be raised up to 5v again after a moment.
And DIG1 keep rising to the voltage as the input.

The DIG1 is not used for AM335X power supply. Just pin out.

Hi Gary,

Can we verify that the powerpad properly soldered to DGND?

Yes, I can check it with customer. Further, will suggest customer to change a new TPS65910 with powerpad properly soldered.

Could you help provide explanation for this? I will use it to persuade customer.

Thanks.

Hi Rick,
Thanks for your help.
Confirmed with customer. They didn't solder PowerPAD. After PowerPAD soldered properly, all voltages are normal.