LM25119 single output setting

Randy Wang

Other Parts Discussed in Thread: LM25119, LM5119

Hi Team

My customer want to use LM25119 do a two phase 24Vin_8Vout_20A application.

There are two questions I need to confirm:

1. The channel2 error amplifier disabled by connecting the FB2 pin to the VCC2 pin, so how about the connection for SS2, I think if channel2 error amplifier has been disabled, SS2 can be floated, is it right?

2. There's few description for single output (two phase operation) application, could you share more document for current sharing and design guide for two phase operation?

Best Regards,

Randy Wang

over 11 years ago

0 EricLee over 11 years ago

TI__Guru 59001 points

By pulling up FB2 pin, only the error amplifier of channel 2 is disabled while the rest functions using SS2 remains.

There is a good article explaining about multi-phase operation at www.ti.com/lit/SLYT449. LM5119's interleaved configuration is explained in the datasheet.

Regards,

0 Randy Wang over 11 years ago in reply to EricLee

TI__Intellectual 1705 points

Hi Eric

Thanks for your reply, the article is good to me.

I saw LM25119 block diagram and find SS is connect to the error amplifier, if the channel 2 error amplifier is disabled, how can ss2 function is still remains?

Best Regards,

Randy Wang

0 EricLee over 11 years ago in reply to Randy Wang

TI__Guru 59001 points

It is not drawn in the block diagram since it is too detail, but LM25119 uses SS pin voltage to reset the device.

If required, slave side Css can be smaller than master side Css.

Regards,

0 Randy Wang over 11 years ago in reply to EricLee

TI__Intellectual 1705 points

thanks, Eric.

It'll be better If you can share me more detail block diagram about LM25119.

0 EricLee over 11 years ago in reply to Randy Wang

TI__Guru 59001 points

I am sorry. I cannot post the details on the public forum. Please contact your local FAE for more support.

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LM25119 single output setting