lmx2335u National Semiconductor Corporation, lmx2335u Datasheet - Page 40

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

www.national.com
Reg. Most Significant Bit
RF1
R
2.0 Programming Description
2.5.4 PWDN RF2
The PWDN RF2 bit is used to switch the RF2 PLL between a powered up and powered down mode.
Furthermore, the PWDN RF2 bit operates in conjuction with the TRI-STATE ID
powerdown mode.
2.6 RF1 R REGISTER
The RF1 R register contains the RF1 R_CNTR, PD_POL RF1, ID
bits that compose the F
discussed in the following sections.
2.6.1 RF1 R_CNTR[14:0]
The RF1 reference divider (RF1 R_CNTR) can be programmed to support divide ratios from 3 to 32767. Divide ratios less than
3 are prohibited.
2.6.2 PD_POL RF1
The PD_POL RF1 bit is used to control the RF1 synthesizer’s phase detector polarity based on the VCO tuning characteristics.
Divide Ratio
F o LD1 F o LD3
PD_POL RF1
PWDN RF2
Control Bit
21
Control Bit
32767
3
4
•
20
STATE
TRI-
RF1
ID o
19
RF1
18
ID o
14
0
0
1
•
o
LD control word. The detailed description and programming information for each control word is
PD_
POL
RF1
Register Location
Register Location
17
RF1 SYNTHESIZER PHASE DETECTOR POLARITY
RF1 SYNTHESIZER PROGRAMMABLE REFERENCE DIVIDER (R COUNTER) RF1 R[2:16]
13
0
0
1
RF2 SYNTHESIZER POWERDOWN
•
RF2 N[21]
RF1 R[17]
16
12
0
0
1
•
15
14
11
0
0
1
•
RF1 VCO Characteristics
13
SHIFT REGISTER BIT LOCATION
(Continued)
10
RF1 Phase Detector
Polarity
0
0
1
•
RF2 Powerdown
Data Field
12
Description
Description
9
0
0
1
•
11
40
o
RF1 R_CNTR[14:0]
RF1 R_CNTR[14:0]
RF1, and TRI-STATE ID
8
0
0
1
•
10
9
7
0
0
1
•
o
RF2 bit to set a synchronous or an asynchronous
RF2 PLL Active
RF1 VCO Negative
Tuning
Characteristics
8
10136782
6
0
0
1
•
7
5
0
0
1
•
0
o
0
RF1 control words, in addition to two
6
4
0
0
1
•
5
Function
Function
4
3
0
0
1
•
RF2 PLL Powerdown
RF1 VCO Positive
Tuning
Characteristics
Least Significant Bit
3
2
0
1
1
•
RF1 R[17]
2
RF2 N[21]
1
1
1
1
0
1
•
Address
1
1
Field
0
1
0
1
•
0
0