0.18um MOSCAP in loop filter

[arpeggi]

In 0.18um technology 1.8V MOS has thinner oxide than 3.3V MOS,
so the unit capacitance of 1.8V MOSCAP is larger than that of 3.3V MOSCAP.

I want to use 1.8V MOSCAP in my loop filter (PLL design) in order to decrease the area occupied by MOSCAP, but I'm worrying about the gate leakage.

Has anybody used the 1.8V MOSCAP in PLL design before?
Please tell me if it is OK to do so. THANKS!

 

[toctory]

gate leakage would increase the output spur.

for reference frequency less than 1MHz, the 1.8V moscap was not recomended.

for freq > 10M, the gate leakage's affect could be omitted