MMPF0100NPANES no VSNVS

[sparkyee]

Hi,

       I have a custom IMX6 board design that has no VSNVS after power is turned on. I have

checked the voltage at VIN on pin 50 and it is 3.6 volts. I have no output on pin 43. This design has no

coin cell only a 0.1uF cap on pin 42. The design emulates the SABRE board in almost all respect. I have attached

my schematic and PMIC program/report files. Could I have inadvertently shut off VSVNS by miss programming?

Any help would be appreciated!

Thanks!

Larry

Original Attachment has been moved to: RTPENGINE-6-21-2016-RPT.txt.zip

Original Attachment has been moved to: RTPENGINE-6-21-2016-PGM.txt.zip

[atillametetured]

Sorry for resurrecting an old post by the way.

[reyes]

Hi Larry,

I’m not sure of what could be causing this issue, if LICELL is not valid before VIN is applied then VSNVS turn-on delay may be extended, but it should turn-on.

VSNVS cannot be disabled, so if you turn on the device without coin cell battery, it derives its power from VIN.

*When powered by VIN, VSNVS is an LDO capable of supplying seven voltages: 3.0, 1.8, 1.5, 1.3, 1.2, 1.1, and 1.0 V. The bits VSNVSVOLT[2:0] in register VSNVS_CONTROL determine the output voltage.

Is VSNVS voltage signal used in other part of the system? If yes, then, can you try to isolate this signal to make sure that it is not a current demand that it is causing the problem?

Jose

[atillametetured]

Hello Jose,

Regarding this subject, may I ask you what happens if PMIC is turned on w/o a coin cell installed. Is it guaranteed that the VSNVS will still be there prior to any other regulator breing up? Since IMX is expecting the VSNVS to be valid before any other source, this is obviously critical. Can we bring the board up without the coin cell?

Regards,

Mete

[reyes]

Hello Mete,

If LICELL is not valid before VIN is applied and assuming that VSNVS is supplied by VIN, then VSNVS turn-on delay may extend to a maximum of 24 ms.

Have a great day,
Jose

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[atillametetured]

Hello Jose,

So it is just extra delay added to the normal operation. Good to know.

Thank you very much,

Mete