LMX2330L National Semiconductor Corporation, LMX2330L Datasheet - Page 13

• Manufacturer Part Number: LMX2330L
• Description: Pllatinum? Low Power Dual Frequency Synthesizer For Rf Personal Communications
• Manufacturer: National Semiconductor Corporation

Functional Description
PROGRAMMABLE REFERENCE DIVIDERS (IF AND RF R COUNTERS)
If the Control Bits are 00 or 01 (00 for IF and 01 for RF) data is transferred from the 22-bit shift register into a latch which sets
the 15-bit R Counter. Serial data format is shown below.
15-BIT PROGRAMMABLE REFERENCE DIVIDER RATIO (R COUNTER)
PROGRAMMABLE DIVIDER (N COUNTER)
The N counter consists of the 7-bit swallow counter (A counter) and the 11-bit programmable counter (B counter). If the Control
Bits are 10 or 11 (10 for IF counter and 11 for RF counter) data is transferred from the 22-bit shift register into a 4-bit or 7-bit latch
(which sets the Swallow (A) Counter) and an 11-bit latch (which sets the 11-bit programmable (B) Counter), MSB first. Serial data
format is shown below. For the IF N counter bits 5, 6, and 7 are don’t care bits. The RF N counter does not have don’t care
bits.
Notes:
Divide
32767
Divide ratios less than 3 are prohibited.
Divide ratio: 3 to 32767
R1 to R15: These bits select the divide ratio of the programmable reference divider.
Data is shifted in MSB first.
Ratio
3
4
•
15 14 13 12 11 10 9
R
0
0
1
•
(Continued)
R
0
0
1
•
R
0
0
1
•
R
0
0
1
•
R
0
0
1
•
R
0
0
1
•
13
R
0
0
1
•
R
8
0
0
1
•
R
7
0
0
1
•
R
6
0
0
1
•
R
5
0
0
1
•
R
4
0
0
1
•
R
3
0
1
1
•
R
2
1
0
1
•
01280607
R
1
1
0
1
•
01280606
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