• Output voltage swing
• Jitter (deterministic, random, peak-to-peak)
• Rise and fall times
• Supply voltage and current
• Noise specification
• Duty cycle and duty-cycle tolerance
• Frequency stability
These characteristics are selection criteria when choosing an oscillator for a GTM transceiver
design.
illustrates the convention for the single-ended clock input voltage swing, peak-
to-peak. This figure is provided to show the contrast to the differential clock input voltage swing
calculation shown in
, as used in the GTM transceiver portion of the Ult device
data sheets (see
http://www.xilinx.com/documentation
Figure 49:
Single-Ended Clock Input Voltage Swing, Peak-to-Peak
+V
Single-Ended Voltage
0
MGTREFCLKP
MGTREFCLKN
X20931-053118
illustrates the differential clock input voltage swing, which is defined as MGTREFCLKP
- MGTREFCLKN.
Figure 50:
Differential Clock Input Voltage Swing, Peak-to-Peak
+V
–V
0
MGTREFCLKP – MGTREFCLKN
V
IDIFF
X20932-053118
shows the rise and fall time convention of the reference clock.
Chapter 5: Board Design Guidelines
UG581 (v1.0) January 4, 2019
Virtex Ult GTM Transceivers
121