Startup by battery - AM335x - TPS65217B

Y tck

Other Parts Discussed in Thread: TPS65217

Hi,

My board is based on AM335x ZCZ,and the power management unit uses a 5V-AC and a battery,the figure below shows detail.

When the AC and the BAT(battery) ON,the board runs OK,and then turn down the AC,the board continue runing powered by the BAT.

But,when I only use the BAT,do not conncet the AC,and push the button,The board can not startup,the voltage is OK,the core PC at address 0x2008c

Can someone help me?Thank you!

Yantck

over 13 years ago

0 Biser Gatchev-XID over 13 years ago

TI__Guru**** 393215 points

Hi Yantck,

Can you tell me the battery voltage and where it is connected?

0 Y tck over 13 years ago in reply to Biser Gatchev-XID

Intellectual 835 points

Hi,Gatchev-XID

The battery voltage pin is connected to BAT1,BAT2,and BAT_SENCE(tps65217 pin4,5,6),and the voltage is 3.6V.

thank you!

0 Biser Gatchev-XID over 13 years ago in reply to Y tck

TI__Guru**** 393215 points

Can you tell me the state of the PGOOD and LDO_PGOOD signals?

0 Y tck over 13 years ago in reply to Biser Gatchev-XID

Intellectual 835 points

Hi,Biser

In my board,the "VIO" is connected to 3V3A,reference to BeagleBone,not "LDO1",is that correct?

Thanck you!

YanTCK

0 Biser Gatchev-XID over 13 years ago in reply to Y tck

TI__Guru**** 393215 points

Hi Yan,

Please check this thread. I think it's related to your problem:

http://e2e.ti.com/support/dsp/sitara_arm174_microprocessors/f/791/t/220444.aspx

0 Y tck over 13 years ago in reply to Biser Gatchev-XID

Intellectual 835 points

HI,Biser

this thread : ***********************************************

From earlier post: “When Wakeup signal goes logic low, Pgood signal (from PMU, normally 3.3V) goes low with 1sn duration and after this situation goes high 1.8V not 3.3V. I suppose PMU changes its state from ACTIVE to WAIT 1sn and OFF state. What are your suggestions?”

What is connected to the VIO pin of the PMIC? Typically this will be LDO1 which will give PGOOD a high level of 1.8V. PGOOD should not have more than one high level.

What does the PGOOD pin go to on the processor? Should be PWRONRSTN.

There is probably something that is connected incorrectly. PGOOD can't be sometimes 3.3V and sometimes 1.8V.

Regarding the nWAKEUP signal from the PMIC:

Typically this only responds to:

Rising edge on USB

Rising edge on AC

Falling edge on PB_IN

****************************************************

So,the "VIO" must be connected to LDO1 not 3V3A,the BeagleBone is incorrect ?

Thank you!

YanTCK

0 Biser Gatchev-XID over 13 years ago in reply to Y tck

TI__Guru**** 393215 points

Hi Yan,

Yes, I think so. This other thread was commented by the PMIC team. By the way, I don't know if you have checked this: http://www.ti.com/lit/ug/slvu551f/slvu551f.pdf. It shows all the connections between the PMIC and the AM335X.

0 Y tck over 13 years ago in reply to Biser Gatchev-XID

Intellectual 835 points

Hi Biser，

Yes,I checked this document,I have a BeagleBone board, my board is referenced to beagleBone,I am very puzzled why the BeagleBone is different from the "Powering the AM335x with the TPS65217x" ？

Thank you ！

YanTCK

0 Y tck over 13 years ago in reply to Biser Gatchev-XID

Intellectual 835 points

Hi Biser，

In additional,the "TPS65217 EVM Uer's Guide",the "VIO" in connected to "V3P3".

YanTCK

0 Biser Gatchev-XID over 13 years ago in reply to Y tck

TI__Guru**** 393215 points

Hi Yan,

I have asked for comments from the PMIC experts on your thread. They should come in later today, possibly tomorrow.

0 Stephen Nortman over 13 years ago in reply to Biser Gatchev-XID

TI__Expert 4525 points

Please see the state diagram on page 16 of the PMIC datasheet.

From OFF state, the PB press should cause you to move to WAIT PWR_EN state. Can you verify that there is a falling edge on the PB node?

During the WAIT PWR_EN state you should see LDO1 go high. Once the SoC sees this 1.8V, it should take PWR_EN high. From there, you should be in active mode.

Please check PB node, LDO1, PWR_EN

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Startup by battery - AM335x - TPS65217B