LMX25311778EVAL National Semiconductor, LMX25311778EVAL Datasheet - Page 30

• Manufacturer Part Number: LMX25311778EVAL
• Manufacturer: National Semiconductor

Specifications of LMX25311778EVAL

• Lead Free Status / Rohs Status: Not Compliant

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2.8 REGISTER R7
2.8.1 XTLDIV[1:0] -- Division Ratio for the Crystal Frequency
The frequency provided to the VCO frequency calibration circuitry is based on the OSCin frequency divided down by a factor,
determined by the XTLDIV word. Note that this division ratio is independent of the R counter value or the phase detector frequency.
The necessary division ratio depends on the OSCin frequency and is shown in the table below:
2.8.2 XTLMAN[11:0] -- Manual Crystal Mode
This word adjusts the calibration timing for lock time in the event that XTLSEL is set to manual mode. In other cases, XTLMAN
should be set to 0. For f
f
OSCin
LMX2531LQ1146E
LMX2531LQ1226E
LMX2531LQ1312E
LMX2531LQ1415E
LMX1531LQ1515E
LMX2531LQ1570E
LMX2531LQ1650E
LMX2531LQ1700E
LMX2531LQ1778E
LMX2531LQ1910E
LMX2531LQ2265E
LMX2531LQ2080E
LMX2531LQ2570E
LMX2531LQ1742
/ Kbit.
Device
XTLDIV
0
1
2
3
OSCin
Kbit
1.5
1.5
1.7
1.7
2.1
2.1
2.3
2.5
2.6
4.5
6.0
2
3
4
frequencies (expressed in MHz) not shown in the table, this bit value can be calculated as 16 ×
5 MHz
53
53
47
47
40
38
38
35
32
31
27
20
18
13
Crystal Division Ratio
10 MHz
36
27
Divide by 2
Divide by 4
Divide by 8
Reserved
(Manual Mode should not be used under these conditions)
30
20 MHz
71
53
f
OSCin
30.72 MHz
109
82
0
61.44 MHz
Crystal Range
20-40 MHz
Reserved
< 20 MHz
> 40 MHz
218
164
76.8 MHz
273
205