S i 5 3 x x - R M
112
Rev. 0.52
8.4. Crystal/Reference Clock Interfaces (Si5316, Si5319, Si5323, Si5324, Si5326, Si5327,
Si5366, Si5368, Si5369, Si5374, and Si5375)
All devices other than the Si5374 and Si5375 can use an external crystal or external clock as a reference. The
Si5374 and Si5375 are limited to an external reference oscillator and cannot use a crystal. If an external clock is
used, it must be ac coupled. With appropriate buffers, the same external reference clock can be applied to CKINn.
Although the reference clock input can be driven single ended (See Figure 51), best performance is with a crystal
or differential LVPECL source. See Figure 55.
If the crystal is located close to a fan, it is recommended that the crystal be covered with some type of thermal cap.
For various crystal vendors and part numbers, see " Appendix A—Narrowband References" on page 118.
1.
For SONET applications, the best jitter performance is with a 114.285 MHz third overtone crystal. The
Si5327 crystal is fundamental mode and is limited to values between 37 MHz and 41 MHz.
2.
The jitter transfer for the external reference to CKOUT is nearly 1:1 (see " Appendix A—Narrowband
References" on page 118.)
3.
In digital hold or VCO freeze mode, the VCO tracks any changes in the external reference clock.
Figure 51. CMOS External Reference Circuit
Figure 52. Sinewave External Clock Circuit
3.3 V
CMOS buffer,
8mA output current
3.3 V
130
150
150
XA
10 k
0.1
F
.6 V
0.1
F
XB
Si53xx
For 1.8 V operation, change 130
to 47.5
.
For 2.5 V operation, change 130
to 82
.
External Clock Source
50
0.01
F
1.2 V
0.6 V
10 pF
Si53xx
10 k
XA
0 dBm into 50
0.01
F
XB
0.1 µF
Содержание Si5316 Series
Страница 2: ...Si53xx RM 2 Rev 0 52 ...
Страница 109: ...Si53xx RM Rev 0 52 109 8 3 Typical Scope Shots for SFOUT Options Figure 46 sfout_2 CMOS Figure 47 sfout_3 lowSwingLVDS ...
Страница 110: ...Si53xx RM 110 Rev 0 52 Figure 48 sfout_5 LVPECL Figure 49 sfout_6 CML ...
Страница 111: ...Si53xx RM Rev 0 52 111 Figure 50 sfout_7 LVDS ...
Страница 127: ...Si53xx RM Rev 0 52 127 Figure 66 155 52 MHz In 622 08 MHz Out Loop BW 7 Hz Si5324 ...
Страница 128: ...Si53xx RM 128 Rev 0 52 Figure 67 19 44 MHz In 156 25 MHz Out Loop BW 80 Hz ...
Страница 129: ...Si53xx RM Rev 0 52 129 Figure 68 19 44 MHz In 156 25 MHz Out Loop BW 5 Hz Si5324 ...
Страница 130: ...Si53xx RM 130 Rev 0 52 Figure 69 27 MHz In 148 35 MHz Out Light Trace BW 6 Hz Dark Trace BW 110 Hz Si5324 ...
Страница 131: ...Si53xx RM Rev 0 52 131 Figure 70 61 44 MHz In 491 52 MHz Out Loop BW 7 Hz Si5324 ...
Страница 132: ...Si53xx RM 132 Rev 0 52 Figure 71 622 08 MHz In 672 16 MHz Out Loop BW 6 9 kHz ...
Страница 133: ...Si53xx RM Rev 0 52 133 Figure 72 622 08 MHz In 672 16 MHz Out Loop BW 100 Hz ...
Страница 134: ...Si53xx RM 134 Rev 0 52 Figure 73 156 25 MHz In 155 52 MHz Out ...
Страница 139: ...Si53xx RM Rev 0 52 139 Figure 78 86 685 MHz In 173 371 MHz Out ...
Страница 140: ...Si53xx RM 140 Rev 0 52 Figure 79 86 685 MHz In 693 493 MHz Out ...
Страница 142: ...Si53xx RM 142 Rev 0 52 Figure 81 10 MHz In 1 GHz Out ...
Страница 174: ...Si53xx RM 174 Rev 0 52 Figure 99 Si5374 Si5375 DSPLL A ...
Страница 175: ...Si53xx RM Rev 0 52 175 Figure 100 Si5374 Si5375 DSPLL B ...
Страница 176: ...Si53xx RM 176 Rev 0 52 Figure 101 Si5374 Si5375 DSPLL C ...