TMS320F28379S: 1.2V Core

PowerGuy

Hi,

I started working with the 320F28379S processor.

On the spec sheet "1.2V Core" is referenced. Can you please explain exactly the use for this 1.2V ?

I have a prototype board and I did not connect the 1.2V to the VDD pins. All other VDDA, VDDIO ... pins have 3.3V going to them.
I have not seen any shortcomings yet and my code appears to work as expected.

Can the processor be used without the 1.2V Core ?

over 7 years ago

0 Peter Galicki over 7 years ago

TI__Expert 8105 points

Please make sure that VREGENz is pulled high. This condition is possible when VREGENz is not pulled high - it will cause internal VREG to supply 1.2V on some similar devices - but on this device it is not supported.

Regards,
Peter

0 PowerGuy over 7 years ago in reply to Peter Galicki

Intellectual 415 points

Peter,

Can you please clarify.

In order for the processor to make Vreg supply the 1.2V, does the VREGENz pin need to be pulled high or low ?

thanks!

0 Peter Galicki over 7 years ago in reply to PowerGuy

TI__Expert 8105 points

Here the description of the VREGENz pin from the datasheet p39:

Internal voltage regulator enable with internal pulldown.
The internal VREG is not supported and must be
disabled. Connect VREGENZ to VDDIO.

Per these instructions please connect VREGENz pin directly to 3.3V (VDDIO)
As this device does not support internal VREG, please do not connect this pin to GND to enable internal VREG.

Regards,
{eter

0 PowerGuy over 7 years ago in reply to Peter Galicki

Intellectual 415 points

got it.
thanks!

VREGENz will be tied to VDDIO.

One last question, all the VDD pins can just get a decoupling capacitor to VSS and have nothing else connected to them correct ?

0 Peter Galicki over 7 years ago in reply to PowerGuy

TI__Expert 8105 points

Yes, that is the case when internal VREG is used. Please see the datasheet for the cap values

REgards,
PEter

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TMS320F28379S: 1.2V Core