LMX2377UTM National Semiconductor, LMX2377UTM Datasheet - Page 37

• 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

Reg. Most Significant Bit
Aux
Divide
N
Ratio
8191
2.0 Programming Description
2.4.4 TRI-STATE ID
The TRI-STATE ID
output state. This happens asynchronously with the change in the TRI-STATE ID
Furthermore, the TRI-STATE ID
powerdown mode.
2.5 AUXILIARY N REGISTER
The Aux N register contains the Aux N_CNTRA, Aux N_CNTRB, PRE Aux, and PWDN Aux control words. The Aux N_CNTRA
and Aux N_CNTRB control words are used to setup the programmable feedback divider. The detailed description and
programming information for each control word is discussed in the following sections.
2.5.1 Aux N_CNTRA[4:0]
The Aux N_CNTRA control word is used to setup the Aux synthesizer’s A counter. The A counter is a 5-bit swallow counter used
in the programmable feedback divider. The Aux N_CNTRA control word can be programmed to values ranging from 0 to 31.
2.5.2 Aux N_CNTRB[12:0] AUXILIARY SYNTHESIZER PROGRAMMABLE BINARY COUNTER (B COUNTER)
Aux N[7:19]
The Aux N_CNTRB control word is used to setup the Aux synthesizer’s B counter. The B counter is a 13-bit programmable binary
counter used in the programmable feedback divider. The Aux N_CNTRB control word can be programmed to values ranging from
3 to 8191.
TRI-STATE ID
3
4
•
Divide Ratio
PWDN
Aux
Control Bit
21
31
0
1
•
PRE
Aux
12
20
0
0
1
•
o
19
Aux
o
11
o
0
0
1
Aux bit allows the charge pump to be switched between a normal operating mode and a high impedance
•
Aux
18
Register Location
17
10
4
0
0
1
•
0
0
1
•
AUXILIARY SYNTHESIZER CHARGE PUMP TRI-STATE CURRENT
AUXILIARY SYNTHESIZER SWALLOW COUNTER (A COUNTER)
o
Aux R[19]
Aux bit operates in conjuction with the PWDN Aux bit to set a synchronous or an asynchronous
16
9
0
0
1
•
15
Aux N_CNTRB[12:0]
14
8
0
0
1
•
13
SHIFT REGISTER BIT LOCATION
3
0
0
1
(Continued)
•
Aux Charge Pump
TRI-STATE Current
Data Field
12
Description
Aux N_CNTRB[12:0]
7
0
0
1
•
11
37
Aux N_CNTRA[4:0]
6
0
0
1
•
10
2
0
0
1
•
9
5
0
0
1
•
Aux Charge Pump
Normal Operation
8
o
Aux bit.
7
4
0
0
1
•
0
6
Aux N_CNTRA[4:0]
3
0
0
1
•
1
0
0
1
•
5
Function
4
2
0
1
1
•
Aux Charge Pump
Output in High
Impedance State
Least Significant Bit
3
Aux R[19]
Aux N[2:6]
2
1
1
0
1
•
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1
0
0
1
1
•
Address
1
0
Field
0
1
0
1
•
0
1