about LTC1856's VREF overdrive

Question

Hi, 
 
 I want to use an external reference to overdrive internal 2.5V reference, but i did not find the voltage range for external reference from the datasheet. 
 Can I use a VREF big than 2.5V such as 2.56V for an &plusmn;10.24V input range? 
 
 Thanks, 
 Yong

ghoover · Answer

The LTC1856 should operate with Vref=2.56V. Because the LTC1856 is not tested under this condition, the ADC accuracy may not meet the data sheet specs.