DS90C383: What is the difference between DS90C383 and DS90C383B

Hi Polly, 

DS90C383B: 18 - 68 MHz shift clock support
Supports Dual pixel SXGA
345 mV swing LVDS
supports spread spectrum clocking

DS90C383 : 20 - 65 MHz shift clock support
290 mV swing LVDS
see fig 15 & 16 for power down timing

You may go through the spec table for the individual spec differences.