7系列参考时钟的抖动的描述方式改变

1万 · 2012-10-31 21:15

6系列的GTX/GTP的参考时钟的抖动在数据手册里面，以ps为单位，7系列的抖动现在还没有进入数据手册，以相位噪声为描述。

http://www.xilinx.com/support/answers/44549.htm

QPLL:

Ref Clock Frequency (MHz)	Phase Noise at Offset Frequency (dBc/Hz)
Ref Clock Frequency (MHz)	10 kHz	100 kHz	1 MHz
100.0	-126	-130	-134
125.0	-123	-129	-133
156.25	-122	-127	-132
250.0	-119	-126	-131
312.5	-115	-124	-130
625.0	-110	-116	-120

Note: If yourdesired reference clock rate is not listed in the table above, please use thephase noise mask for the nearest reference clock frequency.

CPLL:

Ref Clock Frequency (MHz)	Phase Noise at Offset Frequency (dBc/Hz)
Ref Clock Frequency (MHz)	10 kHz	100 kHz	1 MHz
100.0	-126	-132	-136
125.0	-123	-131	-135
156.25	-121	-129	-133
250.0	-119	-126	-132
312.5	-116	-124	-131
625.0	-110	-119	-127

Note: If your desired reference clock rate is not listed in the tableabove, please use the phase noise mask for the nearest reference clockfrequency.