TPS659037: TPS659037 issue

Hi Feng,

I'm trying to reach the poster for his answer; I'll reply you whenever I get the answer.

BTW, another poster had the same issue caused by missing this information: GPIO7 has secondary function as POWERHOLD input; it needs to pull-up.

Thanks!

Phil

Hi  Phil, I noticed GPIO7 in user guide this afternoon, and i pull GPIO7 up, and then i got correct output in some  channels. but other channels do not have correct outputs

Hi Feng,

  Please provide followings for further debug:

1. Text searchable high resolution schematics.
2. OPN
3. List all rails voltage level you measured. 

Thanks!

Phil

Hi Phil, GPIO_7 is the key point.  all outputs are good except LDO4_OUT,  it is expected to be 1.8V, but  it is 2V in fact.  any suggestion?

Hi Feng,

  Please check if the 2V is coming from external of the PMIC. The LDO can source current only; any external source above its output level can impact its normal outoup. 

Thanks!

Phil

Hi Phi,

Please check if the 2V is coming from external of the PMIC---->No, i search the SCH, find LDO4_OUT as a power supply,  connect with the other two place（no more）, refer to these pictures

Hi Feng,

  Please try to disconnect LDO4_OUT from these 2 places and then measure its output without any loads. The 2V may be a leakage from these 2 places. 

Thanks!

Phil

Hi Phi, the other two place are power inputs（AM5728 PCIE POWER AND  GPMC  POwer）

Hi Feng,

  I know they're power inputs. We found some pins (including power input pins) of processor have leakage somehow; just try it. 

Thank!

Phil 

Hi Phi, The board will be broken if i disconnect LDO4_OUT from these 2 place（no registers between them）. can am5728 work normally at this condition?(I do not use PCIe interface, and GPMC is 1.8V)

  You can insert a resistor; the resistor value depends on the current flowing through it. You can measure the voltage difference (in a few mV) on the resistor to tell the current flow direction.

Thanks!
Phil

Hi Phi,

1.You can insert a resistor; the resistor---->How? I never did this

2.Can am5728 work normally at this condition?(I do not use PCIe interface, and GPMC is 1.8V)

Hi Feng,

1. Cut the PCB trace at the LDO output end and solder a SMT resistor with value range from 0.1 Ohm to1 Ohm until you can see the voltage difference. 

2. It works as long as the voltage difference on the resistor <54mV (1.8V-3%).

Thanks!

Phil

Hi Phi,  

if i do nothing,  Can am5728 work normally at this condition?(I do not use PCIe interface, and GPMC is 1.8V)

Hi Feng,

  I don't know; I'm the Apps for the PMIC. Please post another e2e thread with the am5728 processor as part number mentioned. 

Thanks!

Phil

Hi Phi, got it, thanks

Hi Feng,

   You're welcome! Can you close the ticket if no more questions?

Thanks!

Phil 

Hi Phil, how to close it? i do not find the button

Hi Phil

1. can we programme TPS569037 to change LDO4_OUT?

2.I found all of my boards'LDO4_OUT are nearly 2V.

3. I post this issue in processor forum,  I am confused now,  is it the PMIC's issue or the processor's issue?

e2e.ti.com/.../4742586

Hi Feng,

1. You can change LDO4_OUT level by I2C register writing but it comes back after reset; it's an OTP (One Time Programmable) device. 

2.  It may be caused by DVS (Dynamic Voltage Scaling). 

3. Since you don't provide the OPN, and mentioned the processor is AM5728, so, please refer to the "AM572x Industrial Development Kit (IDK) Evaluation Module (EVM) Hardware UG" linked here. 

Thanks!

Phil

Hi Phil, 

Thanks

what's OPN here? in your opinion, can 5728 work normally this time?

Hi Feng,

  OPN is Orderable Part Number; the TPS569037 GPN which has many variants for customer OTP configuration. You can provide a clear top marks picture from the device to me to check its OPN for details.

Thanks!

Phil

Hi Phil, thanks

Hi Feng,

  From the picture, the PMIC OPN is TPS6590379ZWSR. Please also check the UG "TPS659037 User's Guide to Power AM574x, AM572x, and AM571x (Rev. F): linked here.

Thanks!

Phil