lmx2335u National Semiconductor Corporation, lmx2335u Datasheet - Page 38

• Manufacturer Part Number: lmx2335u
• Description: Pllatinum Ultra Low Power Dual Frequency Synthesizer For Rf Personal Communications
• Manufacturer: National Semiconductor Corporation

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Reg. Most Significant Bit
RF2
R
2.0 Programming Description
2.4 RF2 R REGISTER
The RF2 R register contains the RF2 R_CNTR, PD_POL RF2, ID
bits that compose the F
discussed in the following sections. RF2 R_CNTR[14:0]
2.4.1 RF2 R_CNTR[14:0]
The RF2 reference divider (RF2 R_CNTR) can be programmed to support divide ratios from 3 to 32767. Divide ratios less than
3 are prohibited.
2.4.2 PD_POL RF2
The PD_POL RF2 bit is used to control the RF2 synthesizer’s phase detector polarity based on the VCO tuning characteristics.
2.4.3 ID
The ID
Divide Ratio
F o LD0 F o LD2
PD_POL RF2
21
Control Bit
Control Bit
32767
ID
o
o
3
4
•
RF2 bit controls the RF2 synthesizer’s charge pump gain. Two current levels are available.
o
RF2
20
RF2
STATE
TRI-
RF2
ID o
19
RF2
18
ID o
14
0
0
1
•
o
RF2 SYNTHESIZER CHARGE PUMP CURRENT GAIN
LD control word. The detailed description and programming information for each control word is
PD_
POL
RF2
Register Location
Register Location
17
RF2 SYNTHESIZER PHASE DETECTOR POLARITY
RF2 SYNTHESIZER PROGRAMMABLE REFERENCE DIVIDER (R COUNTER) RF2 R[2:16]
13
0
0
1
•
RF2 R[17]
RF2 R[18]
16
12
0
0
1
•
15
14
11
0
0
1
•
RF2 VCO Characteristics
13
SHIFT REGISTER BIT LOCATION
(Continued)
10
RF2 Phase Detector
Polarity
RF2 Charge Pump
Current Gain
0
0
1
•
Data Field
12
Description
Description
9
0
0
1
•
11
38
o
RF2 R_CNTR[14:0]
RF2 R_CNTR[14:0]
RF2, and TRI-STATE ID
8
0
0
1
•
10
9
7
0
0
1
•
RF2 VCO Negative
Tuning
Characteristics
8
10136786
6
0
0
1
•
0.95 mA
7
LOW
5
0
0
1
•
o
0
0
RF2 control words, in addition to two
6
4
0
0
1
•
5
Function
Function
4
3
0
0
1
•
RF2 VCO Positive
Tuning
Characteristics
Least Significant Bit
3
2
0
1
1
•
3.80 mA
RF2 R[17]
HIGH
RF2 R[18]
2
1
1
1
1
0
1
•
Address
1
0
Field
0
1
0
1
•
0
0