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Entry  Mon Oct 19 11:26:29 2009, Jinhong Wang, output common mode voltage of DRS4 
    Reply  Mon Oct 19 12:46:12 2009, Stefan Ritt, output common mode voltage of DRS4 
Message ID: 20     Entry time: Mon Oct 19 12:46:12 2009     In reply to: 19
Author: Stefan Ritt 
Subject: output common mode voltage of DRS4 

Jinhong Wang wrote:
Does it mean that this buffer shifts a voltage of about 1.3V for the primary differential range? 

No. It shifts about ROFS-0.25V. So only if ROFS=1.55V, the shift will be 1.3V.

Jinhong Wang wrote:
Again for the differential range of -0.5V~0.5V, can the common mode voltage of the analog output at OUT+/OUT-  be chaned?

Just read the datasheet under "ANALOG OUTPUTS". I'm sorry if I did not describe this clearly, but the U+ voltage is fixed (only dependent on ROFS), and U- can be calculated using Uofs as written in the datasheet. 

Jinhong Wang wrote:
In the example presented in the datasheet, OUT+ is 0.8V~1.8V and OUT- is 1.8V~0.8V. So for an output swing of 2V p-p, can the common mode voltage be modified to the desired value? Supposed that the input ranges from -0.5V~0.5V.

OUT+ is 0.8V~1.8V, OUT- is 2*Uofs-OUT+. So you can only change the OUT- level, not the OUT+ level. 

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