DAC8775: DAC8775 Internal power supply design

Lei wang

Part Number: DAC8775

Hi Sir

I want to use DAC8775 but have a question. Reference evaluation board. I want Reduce PCB area, SO I want to know that LP_X,LN_X,VPOS_IN_X,VNEG_IN_X:(A,B,C,D) .May I connect the A,B,C,D to a node.

over 5 years ago

0 Paul_Frost over 5 years ago

TI__Guru 53353 points

Hi Lei,

My colleague should be able to help you with this, though note that with the recent holidays, responses will be delayed.

Thanks,
Paul

0 Paul_Frost over 5 years ago in reply to Paul_Frost

TI__Guru 53353 points

Hi Lei,

Can you clarify your question - are you trying to use only one of the DC/DC converters?

Thanks,
Paul

0 Lei wang over 5 years ago in reply to Paul_Frost

Expert 1620 points

Yes

0 Garrett Satterfield over 5 years ago in reply to Lei wang

TI__Expert 5820 points

Hi Lei,

LP_X, LN_X, VPOS_IN_X, and VNEG_IN_X of unused channels should be left unconnected.

Thanks,
Garrett

0 Lei wang over 5 years ago in reply to Garrett Satterfield

Expert 1620 points

Hi Garrett:

I want to use for channel, but for power external circuit for LP_X, LN_X, VPOS_IN_X, and VNEG_IN_X , I want use 1 or 2.

0 Garrett Satterfield over 5 years ago in reply to Lei wang

TI__Expert 5820 points

Hi Lei,

Each LP output should connect to an inductor for the DC/DC of each channel. They cannot be connected as you show above. See Figure 135 and figure 136 of the datasheet.

Thanks,
Garrett

0 Lei wang over 5 years ago in reply to Garrett Satterfield

Expert 1620 points

The red line I will place four. But others I want to 1 or 2. Is OK？

0 Garrett Satterfield over 5 years ago in reply to Lei wang

TI__Expert 5820 points

Hi Lei,

I am not sure what you mean by this. Can you explain further?

Thanks,
Garrett

0 Garrett Satterfield over 5 years ago in reply to Garrett Satterfield

TI__Expert 5820 points

Hi Lei,

Any update on this?

Thanks,
Garrett

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DAC8775: DAC8775 Internal power supply design