Reply
Highlighted
Posts: 1
Registered: ‎07-11-2014

How to get common mode voltage from the cross point voltage at 0.7V swing?

Hi We are using Si52146 part
generating ref clock to SOC chip in our board.
For my SOC chip,the ref clock specs are
1.The Common mode Voltage (single ended) is 0.2 to 1.1 V
2.Pk-Pk Mode Voltage(single ended) is 0.5 to 2.4V

In your clock generator part data sheet, you have specified cross point voltage & voltage high,low values.  I need to calculate the
Common mode voltage of your chip,to check the compatibility of loading with my SOC chip.
Please clarify.

 

Regards,

S.Sathiya Seelan

Posts: 42
Registered: ‎02-24-2014

Re: How to get common mode voltage from the cross point voltage at 0.7V swing?

The swing is 0.7V (Pk-Pk single ended).

The common mode voltage = 0.35 V.

 

Even though common mode voltage is not listed in the datasheet, you can see that Vhigh and Vlow are specified. The common mode  = (Vhigh + Vlow)/2.

Typically, Vlow  = 0V and Vhigh  = 0.7V => Common mode  = 0.35.

 

In the worst case according to datasheet specs, Common mode  = (1.15 -0.3)/2  = 0.425V.

 

Si52146 meets both the needs of the receiver.