LMX2377UTM National Semiconductor, LMX2377UTM Datasheet - Page 38

• Manufacturer Part Number: LMX2377UTM
• Description: IC FREQ SYNTH DUAL 20TSSOP
• Manufacturer: National Semiconductor
• Series: PLLatinum™r
• Type: PLL Frequency Synthesizerr

Specifications of LMX2377UTM

• Pll: Yes with Bypass
• Input: CMOS, TTL
• Output: CMOS
• Number Of Circuits: 1
• Ratio - Input:output: 3:1
• Differential - Input:output: Yes/No
• Frequency - Max: 2.5GHz, 1.2GHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP
• Frequency-max: 2.5GHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *LMX2377UTM

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Main
Reg. Most Significant Bit
R
2.0 Programming Description
2.5.3 PRE Aux
The Aux synthesizer utilizes a selectable dual modulus prescaler.
2.5.4 PWDN Aux
The PWDN Aux bit is used to switch the Aux PLL between a powered up and powered down mode.
Furthermore, the PWDN Aux bit operates in conjuction with the TRI-STATE ID
powerdown mode.
2.6 MAIN R REGISTER
The Main R register contains the Main R_CNTR, PD_POL Main, ID
to two bits that compose the F
discussed in the following sections.
2.6.1 Main R_CNTR[14:0] MAIN SYNTHESIZER PROGRAMMABLE REFERENCE DIVIDER (R COUNTER)
Main R[2:16]
The Main reference divider (Main R_CNTR) can be programmed to support divide ratios from 2 to 32767. Divide ratios less than
2 are prohibited.
Divide Ratio
F o LD1 F o LD3
Control Bit
Control Bit
21
PWDN Aux
32767
PRE Aux
2
3
•
20
STATE
Main
TRI-
ID o
19
Main
18
ID o
14
0
0
1
•
Main
PD_
POL
Register Location
Register Location
17
13
o
AUXILIARY SYNTHESIZER PRESCALER SELECT
AUXILIARY SYNTHESIZER POWERDOWN
0
0
1
•
LD control word. The detailed description and programming information for each control word is
Aux N[20]
Aux N[21]
16
12
0
0
1
•
15
14
11
0
0
1
•
13
SHIFT REGISTER BIT LOCATION
(Continued)
10
Aux Prescaler Select
0
0
1
•
Data Field
Aux Powerdown
12
Description
Description
9
0
0
1
•
11
38
Main R_CNTR[14:0]
Main R_CNTR[14:0]
8
0
0
1
•
o
10
Main, and TRI-STATE ID
9
7
0
0
1
•
o
Aux bit to set a synchronous or an asynchronous
8/9 Prescaler
Selected
Aux PLL Active
8
6
0
0
1
•
7
5
0
0
1
•
0
0
6
o
Main control words, in addition
4
0
0
1
•
5
Function
Function
4
3
0
0
1
•
16/17 Prescaler
Selected
Aux PLL Powerdown
Least Significant Bit
3
2
0
0
1
•
2
Aux N[21]
Aux N[20]
1
1
1
1
1
1
•
Address
1
1
Field
0
0
1
1
•
0
0