LMX2306TMX/NOPB National Semiconductor, LMX2306TMX/NOPB Datasheet - Page 8

• Manufacturer Part Number: LMX2306TMX/NOPB
• Description: IC FREQ SYNTH LOW PWR 16-TSSOP
• Manufacturer: National Semiconductor
• Series: PLLatinum™r
• Type: PLL Frequency Synthesizerr

Specifications of LMX2306TMX/NOPB

• Pll: Yes
• Input: CMOS
• Output: CMOS
• Number Of Circuits: 1
• Ratio - Input:output: 2:1
• Differential - Input:output: No/No
• Frequency - Max: 550MHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 2.3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP
• Frequency-max: 550MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LMX2306TMX; *LMX2306TMX/NOPB; LMX2306TMX; LMX2306TMX; LMX2306TMXTR

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1.0 Functional Description
1.2 PROGRAMMABLE DIVIDER (N COUNTER)
The N counter consists of the 5-bit swallow counter (A counter) and the 13-bit programmable counter (B counter). If the Control
Bits are [C
a 13-bit latch (which sets the 13-bit programmable (B) Counter), and the GO bit (See Section 1.3.4 FastLock MODES section)
MSB first. For the LMX2306 the maximum N value is 65535 and the minimum N value is 56. For the LMX2316/26, the maximum
N value is 262143 and the minimum N value is 992. Serial data format is shown below.
Note: Data is shifted in MSB first.
1.2.1 5-bit Swallow Counter Divide Ratio (A Counter)
Note: Divide ratio: 0 to 31
B ≥ A
1.2.2 13-Bit Programmable Counter Divide Ratio (B Counter)
1.2.3 Pulse Swallow Function
fvco = [(P x B) + A] x fosc/R
f
B:
A:
f
R:
P:
vco
osc
Divide ratio: 3 to 8191 (Divide ratios less than 3 are prohibited) B≥A
: Output frequency of external voltage controlled oscillator (VCO)
: Output frequency of the external reference frequency oscillator
Divide
Divide
Divide
Ratio
Ratio
Ratio
8191
Preset divide ratio of binary 13-bit programmable counter (3 to 8191)
Preset divide ratio of binary 5-bit swallow counter (0 ≤ A ≤ 31; A ≤ B for LMX2316/26)
or (0 ≤ A ≤ 7, A ≤ B for LMX2306)
Preset divide ratio of binary 14-bit programmable reference counter (3 to 16383)
Preset modulus of dual modulus prescaler
for the LMX2306; P = 8 for the LMX2316/26; P = 32
31
0
1
0
•
3
4
•
1
, C
2
] = [1,0], data is transferred from the 21-bit shift register into a 5-bit latch (which sets the Swallow (A) Counter),
18
N
0
0
1
•
N
N
X
5
0
0
1
5
•
LMX2316/26
LMX2306
17
N
0
0
1
•
N
N
X
4
0
0
1
4
•
16
N
0
0
1
•
N
N
3
0
0
1
3
0
•
15
N
0
0
1
N
N
•
2
0
0
1
2
0
•
(Continued)
14
N
0
0
1
N
N
•
1
0
1
1
1
0
•
13
8
N
0
0
1
•
Note: Divide ratio: 0 to 7
B ≥ A
X denotes a Don’t Care condition
Divide
12
Ratio
N
0
0
1
•
1
7
•
11
N
0
0
1
•
N
5
X
X
•
10
N
0
0
1
•
N
X
X
4
•
N
9
0
0
1
•
N
3
0
1
•
N
8
0
1
1
10012706
•
N
2
0
1
•
N
7
1
0
1
•
N
6
1
0
1
•
N
1
1
1
•