ICS84330-02 Datasheet, PDF (9/17 Pages) Integrated Circuit Systems – 700MHZ, LOW JITTER, CRYSTAL-TO-3.3V DIFFERENTIAL LVPECL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
ICS84330-02
700MHZ, LOW JITTER, CRYSTAL-TO-3.3V
DIFFERENTIAL LVPECL FREQUENCY SYNTHESIZER
LVCMOS TO XTAL INTERFACE
The XTAL_IN input can accept single ended LVCMOS signal
through an AC couple capacitor. A general interface diagram
is shown in Figure 4. The XTAL_OUT input can be left floating.
The edge rate can be as slow as 10ns. If the incoming signal
has sharp edge rate and the signal path is a long trace, proper
termination for the driver and controlled characteristic imped-
ance trace may be required. The input can function with half
swing amplitude. Reducing amplitude from full swing of 3.3V
to half swing of about 1.65V can prevent signal interfere with
power rail and may reduce noise. Please refer to the LVCMOS
driver data sheet and application note for amplitude reduction
and termination approach.
3.3V
LVCMOS_Driv er
C1
0.1uF
XTAL_IN
XTAL_OUT
Cry stal Interf ace
Figure 4. GENERAL DIAGRAM FOR LVCMOS DRIVER TO XTAL INPUT INTERFACE
50
40
30
20
10
0
200
Spec Limit
N=1
300
400
500
600
700
Output Frequency (MHz)
FIGURE 5. CYCLE-TO-CYCLE JITTER VS. fOUT (using a 16MHz XTAL)
84330AV-02
www.icst.com/products/hiperclocks.html
9
REV. A MAY 31, 2005