[SI-LIST] Re: 答复: About Power Management IC which can sink current

  • From: Peter Sørensen <pso@xxxxxxxxxxxxxxxxx>
  • Date: Wed, 10 Sep 2008 10:45:14 +0200

Im not sure I can claim the title Guru but I can add a little 
information on this one.
A short look on the LTC3776 datasheet shows that it use a symmetrical 
pair of FETs instead of only one FETs from the positive supply.
So the additional FET to GND can sink current when then output voltage 
becomes to high due to outputs switching high.

best regards

Peter Sorensen


Zhangkun wrote:
> Hi Han
>
> In the VTT of DDR, the source and sink current is of high frequency, which
> is provided by the decoupling capacitor.
>
> Hope this is helpful
>
> Best Regards
>
> Zhangkun
> 2008.9.10 
>
>
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> å??件人: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
> 代表 Han Li
> å??é??æ?¶é?´: 2008å¹´9æ??8æ?¥ 11:06
> �件人: SI LIST
> 主�: [SI-LIST] About Power Management IC which can sink current
>
> Hi, Gurus,
>      In DDR termination, Vtt requirements a Power Supply IC that can sink
> and source current. Many of these are LDO, some are DC-DC(such as Linear's
> LTC3776).
> I wondered how does current flow into a DC-DC when in sink mode. (It seems
> relatively easier to analyze when an IC is a LDO, but swithing an one). What
> is the sink-current path inside an IC. Does it have an inside load which
> porvides a path to ground?
> Thank you very much.
>
>
>
>
> --
> Best Regards
> Li Han
>
>
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