relationship between VREF and input range Vpp

This is the figure of AD9213's datasheet.

Hi Thomas0214 

Thanks for your interest in AD9213.

In many ADCs, the reference voltage (VREF) is used to set the full-scale range of the input signal. For the AD9213, I think the internal architecture and gain stages are designed such that a 0.5V VREF results in a 1.4V differential input range. Also, this might be a result of the specific internal scaling and conversion factors used in the ADC design.

Kindly give some time for the product owner () to look into this and provide their response.

Thanks. Look forward to your reply!

Is there a more detailed answer to this question?

Hello,

While scaling factor of 1 or 2x of VREF is often the case.......it need not be that always and can be set by changing gain setting resistors as shown on some other ADC's below.  While the AD9213 has a different implementation (i.e. R2/R1 resides is fixed and resides inside the device).............the example below shows that it is possible to have a full-scale input of 1.4 Vpp while having a 0.5 V VREF.