AD9576/PCBZ EVB positive clock


I'm using the evaluation board of the AD9576 chip. From the datasheet looks like it's positive to obtain only positive voltage clock signals (pg:23 figs:12, 15 and 16).

I wonder if those graphs were taking directly from the board or extra hardware needs it.

The chip to use the clock admits only positive signals, it could break if a negative signal is used.

King regards,

Ivan Herrera