LMX2331LSLBX National Semiconductor, LMX2331LSLBX Datasheet - Page 16

• Manufacturer Part Number: LMX2331LSLBX
• Description: PLL Frequency Synthesizer Dual 45MHz to 2000MHz 24-Pin LAM CSP T/R
• Manufacturer: National Semiconductor
• Type: PLL Frequency Synthesizerr

Specifications of LMX2331LSLBX

• Package: 24LAM CSP
• Number Of Elements Per Chip: 2
• Operating Temperature: -40 to 85 °C
• Operating Supply Voltage: 3 V

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PROGRAMMABLE MODES
Several modes of operation can be programmed with bits R16–R20 including the phase detector polarity, charge pump TRI-STATE
and the output of the F
modes are shown in
Note 9: Refer to POWERDOWN OPERATION in Functional Description.
Note 10: The I
Note 11: PHASE DETECTOR POLARITY
0
1
Depending upon VCO characteristics, R16 bit should be set accordingly: (see figure right)
When VCO characteristics are positive like (1), R16 should be set HIGH;
When VCO characteristics are negative like (2), R16 should be set LOW.
Phase Detector Polarity
CPo
(Note
Negative
LOW current state = 1/4 × I
Positive
C1
0
0
Table
11)
o
LD pin. The prescaler and powerdown modes are selected with bits N19 and N20. The programmable
C2
0
1
1. Truth table for the programmable modes and F
Detector Polarity
Detector Polarity
RF Phase
Normal Operation
IF Phase
12806 Version 9 Revision 2
D
CPo
R16
o
TRI-STATE
C1
TRI-STATE
1
1
(Note
HIGH current.
TABLE 2. Mode Select Truth Table
C2
9)
0
1
TABLE 1. Programmable Modes
VCO Characteristics
RF Prescaler
RF I
IF Prescaler
IF I
R17
(Note
CPo
N19
HIGH
CPo
LOW
I
CPo
Print Date/Time: 2011/07/11 15:54:42
10)
16
TRI-STATE
TRI-STATE
Prescaler
RF D
IF D
R18
16/17
8/9
IF
o
o
Pwdn RF
o
Pwdn IF
LD output are shown in
1280609
N20
Prescaler
2330L RF
32/33
64/65
RF LD
IF LD
R19
2331L/32L RF
Prescaler
128/129
64/65
Table 2
RF F
IF F
R20
o
o
and
Table
Pwrd Up
Pwrd Dn
(Note
Pwdn
3.
9)