OMAP-L138: Consult the CVDD of OMAP-L138

Li Shawn

Part Number: OMAP-L138

Hi Team,

I noticed the OMAP-L138 support the multiple voltage operating point of CVDD and RVDD. from the datasheet POV(Code:OMAPL138EZCED4), we can connect the CVDD and RVDD together with 1.2V power supply, by this way we can reduce a 1.3V regulator model. changing CVDD from 1.3V to 1.2V, except the the power consumption and the clock frequency limitation, is there any other risk for the hardware design and software design? would please share some hints with us? thanks for your support!

Br,

Shawn Li

over 3 years ago

0 peaves over 3 years ago

TI__Guru 63235 points

CVDD supports voltage scaling, but RVDD requires a fixed voltage supply. So voltage scaling on CVVD can not be used when connecting CVDD and RVDD to the same 1.2V power supply. This will also limit the maximum operating frequency to 375 MHz.

The Power-On Sequence section of the datasheet has a statement in #2 (Core logic supplies) that addresses your question. It says "If voltage scaling is not used on the device, groups 2a) and 2b) can be controlled from the same power supply and powered up together.". CVDD is listed in 2a and RVDD is listed in 2b, so they can be connected together.

Regards,
Paul

0 Li Shawn over 3 years ago in reply to peaves

Prodigy 50 points

Hi Paul,

Thanks for your reply!

I`ll give up the voltage scaling feature, if take this way, the whole DSP power consumption will increase than using voltage scaling. If to use the 456MHz work frequency, it is ok to connect CVDD and RVDD together with 1.3V power supply, am I right? please help me confirm this point, thanks in advance.

Br,

Shawn Li

0 peaves over 3 years ago in reply to Li Shawn

TI__Guru 63235 points

Yes, but this operating mode does not support the Extended Temperature range. So you must maintain a max junction temperature of 90°C.

Regards,
Paul

0 Li Shawn over 3 years ago in reply to peaves

Prodigy 50 points

Hi Paul,

Thanks for your friendly answer! you can close this ticket.

Br,

Shawn Li

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Arabic	Hebrew	Polish
Bulgarian	Hindi	Portuguese
Catalan	Hmong Daw	Romanian
Chinese Simplified	Hungarian	Russian
Chinese Traditional	Indonesian	Slovak
Czech	Italian	Slovenian
Danish	Japanese	Spanish
Dutch	Klingon	Swedish
English	Korean	Thai
Estonian	Latvian	Turkish
Finnish	Lithuanian	Ukrainian
French	Malay	Urdu
German	Maltese	Vietnamese
Greek	Norwegian	Welsh
Haitian Creole	Persian

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OMAP-L138: Consult the CVDD of OMAP-L138