About DS25BR110

Hi Kanemaru San,

DS25BR110 has wide input common mode voltage range. Input common mode voltage is from 0.05 to Vcc-0.05. Thus you can either DC couple or AC couple as long as the common mode voltage is in this range. Further please make sure Input common voltage + or - VOD/2 is within GND to Vcc range. If you like, please let us know your transmitter specifications so we can comment further.

Regards,,nasser 

Hi nasser

thank you very much.

Please let me ask one more. 

 When carrying out AC cupling, is Vbias required before DS25BR110?
(Please refer to "P36　AC Coupling" of the following URL. )

*Voltage after AC coupling 　is "VDO/2 = GND".I think that it cannot receive the above-mentioned voltage when there is no Vbias before DS25BR110.

<URL>

http://webench.national.com/assets/en/appnotes/National_LVDS_Owners_Manual_4th_Edition_2008.pdf

Regards, Kanemaru

Kanemaru-San,

As shown in Test Circuit in the data sheet, when we AC couple there is no need for setting up Vbias. However, if input could be floating or not driven then it would be a good idea to set a weak bias to force constant low or high.

Regards,,nasser

Hi, nasser

Does DS25BR110 have internal bias circuit at IN+/- pin ?

If the answer is YES, I understood that the device could be AC coupled without external bias circuit.

If NO, I cannot understand the test circuit in the datasheet, because it is out of VCMR (VCM=GND).

Regards, Kanemaru

Kanemaru-San,

I appologize for answering this late.

Yes your understanding is correct. DS25BR110 has internal bias circuit at IN+/-.

Please let us know if there is further question.

Regards,,nasser