AM62A7: TPS65931211RWERQ1 used with AM62A74AUMSIAMBRQ1

chandrashekhar Venkatesh

Part Number: AM62A7

Tool/software:

We are facing issue with processor loads high current at start up due to this PMIC hiccup and detect under voltage at 5V input.

Below is the circuit, we use 5V input at switching regulators and 3,3V to rest of power input of PMIC.

In datasheet it says Vin vs VDDA to be same or not higher than 0.5Volts difference could this cause this behavior.

When we keep Processor AM62A74AUMSIAMBRQ1 under reset condition, means removed pullup resistor connected to nRSTOUT(PIN 25) from PMIC, which connect to Processor MCU_PORZ(A7 ball), all power come good. The moment if we power on the board with nRSTOUT with pullup resistor to 1.8V(which is Buck 5 output) we run in to issue of PMIC reboot multiple times after few seconds(3 seconds) it powers off all power outputs except LDOVINT & LDOVRTC.

Rgds

Chandra

11 months ago

0 Kallikuppa Sreenivasa 11 months ago

TI__Guru**** 192589 points

Hello Chandra

Thank you for the query.

Based on your inputs, i assume that there is no issue with the PMIC operation.

Is the understanding correct?

If that is the case, may be you will have to review the SOC and related circuit implementation to ensure there is not voltage connect to any of the SOC inputs before supply ramps or any of the SOC IOs are pulled to a supply that is available before the SOC supplies ramp.

Regards,

Sreenivasa

0 chandrashekhar Venkatesh 11 months ago in reply to Kallikuppa Sreenivasa

Prodigy 60 points

Yes, If Processor is in Reset state all PMIC supply come good. If processor come out of reset state we have > 3Amps current drawn at 5Volts supply line. This is puzzling us. Why such high current.

0 Kallikuppa Sreenivasa 11 months ago in reply to chandrashekhar Venkatesh

TI__Guru**** 192589 points

Hello Chandra

Thank you.

Please refer the current consumption.

https://www.ti.com/lit/pdf/sprada7

I do not have the design information to comment.

Regards,

Sreenivasa

0 Paul Chacko 11 months ago in reply to Kallikuppa Sreenivasa

Intellectual 613 points

Hello Kallikuppa Sreenivasa,

VCCA =3.3V and

PVIN_B1 to B5 are 5V. Thus, the voltage difference between Supply pin's difference is more than 0.5V (which violates the datasheet recommendation.

Is it a problem or we can ignore this?

Thanks,

Paul

0 Kallikuppa Sreenivasa 11 months ago in reply to Paul Chacko

TI__Guru**** 192589 points

Hello Paul,

Thank you.

Let me review and comeback.

I may have to reassign to the PMIC team.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa 11 months ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 192589 points

Hello Paul,

Please refer below appnote

https://www.ti.com/lit/ug/slvucm3/slvucm3.pdf

Can you please confirm you are following the guidelines for 5V input.

Regards,

Sreenivasa

0 Paul Chacko 11 months ago in reply to Kallikuppa Sreenivasa

Intellectual 613 points

Hello Sreenivasa,

We did the correction and it is working now.

Thank you for your supports.

Regards,

Paul

0 Kallikuppa Sreenivasa 11 months ago in reply to Paul Chacko

TI__Guru**** 192589 points

Hello Paul,

Good to hear and happy to support.

If you could summarize the changes done, it would help.

Regards,

Sreenivasa

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AM62A7: TPS65931211RWERQ1 used with AM62A74AUMSIAMBRQ1