Si53xx-RM
Rev. 0.52
85
7.5.3. Free Run Reference Frequency Constraints
All crystals and external oscillators must lie within these two bands
Not every crystal will work; they should be tested
An external oscillator can be used at all four bands
The frequency at the phase detector (f3) must be the same for both CKIN1 and XA/XB or else switching cannot
be hitless
To avoid spurs, avoid outputs that are an integer (or near integer) of the XA/XB frequency.
7.5.4. Free Run Reference Frequency Constraints
While in Free Run:
CKOUT frequency tracks the reference frequency.
For very low drift, a TCXO or OCXO reference is necessary.
CKOUT Jitter:
XA/XB to CKOUT jitter transfer function is roughly one-to-one.
For very low jitter, either use a high quality crystal or external oscillator.
3rd overtone crystals have lower close-in phase noise.
In general, higher XA/XB frequency > lower jitter.
XA/XB frequency accuracy:
For hitless switching, to meet all published specifications, the XA/XB frequency divided by N32 should match the CLKIN
frequency divided by N31. If they do not match, the clock switch will still be well-behaved.
Other than the above, the absolute accuracy of the
XA/XB
frequency is not important.
XA/XB Frequency Min
XA/XB Frequency Max
Xtal
109 MHz
125.5 MHz
3rd overtone
37 MHz
41 MHz
Fundamental
CKIN
N31
---------------
XA-XB
N32
------------------
f
3
=
=
CKOUT
XA-XB
----------------------
Integer
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 ...