Power sequence question about SND9039 when power shutdown abnormally on Intel Cherry trail platform

Gary Teng

Dear Sir,

My customer has question on using SN9039 with Intel Cherry Trail platform on IPC application: when the system power is down abnormally, SN9039's will have abnormal power sequence on buck6(V1P8A), buck3(V1P15) and buck5(VNN) and will cause system halted before cleaning CMOS on intel NUC. Is there any method to solve the system halted issue on modifying SN9039's power off sequence ?

CH1: +V1.8 CH2: _V1.15 CH3: VNN Ch4: 5V

Or can customer use VBATSENSE signal or other method to force system into cold off sequence when abnormal power down?

Best regards,

Gary Teng

over 8 years ago

0 James Lockridge19 over 8 years ago

TI__Genius 14487 points

Hello Gary,

Let me contact the applications engineer who supports this part.

0 Gary Teng over 8 years ago in reply to James Lockridge19

Genius 5860 points

Hi James,

Do you have idea about the question currently? Thanks.

Gary

0 Costin Cazana over 8 years ago in reply to Gary Teng

TI__Expert 4940 points

Hi Gary,

Does customer has an NDA?

The application is DollarCove type for CherryTrail system?

The cold off power sequence is different from SND9039 Cherry Trail cold off sequence, the actual sequence is:

Regarding VBATSENSE, the answer is yes, when VBAT falls below the threshold programed in register VBATTHR( default 2.7V) SND9039 will star cold off sequence.

Regards,

Costin

0 Hank Ho over 8 years ago in reply to Costin Cazana

Prodigy 30 points

Hi Costin,

About the SND9039 will star cold off sequence, can you help me to modify snd9039 FW to adjust the cold off sequence, make +V1.8A falling before +V1.0A and make VNN falling after +V1.0A~thanks.

Hank

0 Hank Ho over 8 years ago in reply to Costin Cazana

Prodigy 30 points

Hi Costin,

Can you help me to adjust the SND9039 FW register value to 111 of VBATUVLOTHR(2:0)~thanks.

Hank

0 Costin Cazana over 8 years ago in reply to Hank Ho

TI__Expert 4940 points

Hi Hank,

If I understood your question, anytime after "Mechanic off' state you can modify ( write) the registers.
Setting reg18 D5:3 to 111 will set the threshold to 3.2V( default 2.7V). I will not recommend this without modifying the default(3.3V) power up threshold, the hysteresis is small, that's a risk due to noise to be unstable if Vbat~3.25V

Regards,
Costin

0 Costin Cazana over 8 years ago in reply to Hank Ho

TI__Expert 4940 points

Hi Hank,

I think I didn't paste the SND9039 CHT Cold Off sequence in my previous reply. You don't need to modify the sequence, that's how the sequence work, last 5 bucks/ldos are:

Buck4-VDDQ

Buck6-V1P8A

LDO1-V1P2A

Buck3-V1P05A

Buck2-VNN

I'll e-mail you directly this sequence.

Regards,

Costin

0 Costin Cazana over 8 years ago in reply to Costin Cazana

TI__Expert 4940 points

Hi Hank,

I can not insert the sequence, I e-mailed it to you

Regards,
Costin

0 Costin Cazana over 8 years ago in reply to Costin Cazana

TI__Expert 4940 points

Hi Hank,

What is your e-mail address?
What I found bounced back.

Regards,
Costin

0 Hank Ho over 8 years ago in reply to Costin Cazana

Prodigy 30 points

Hi Costin,

My e-mail address is Hank_Ho@avalue.com.tw.
Thanks for your support.

Hank

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Power sequence question about SND9039 when power shutdown abnormally on Intel Cherry trail platform