LMX2531LQE1226E/NOPB National Semiconductor, LMX2531LQE1226E/NOPB Datasheet - Page 29

• Manufacturer Part Number: LMX2531LQE1226E/NOPB
• Description: IC PLL FREQ SYNTH W/VCO 36-LLP
• Manufacturer: National Semiconductor
• Series: PowerWise®r
• Type: Clock/Frequency Synthesizer (RF)r

Specifications of LMX2531LQE1226E/NOPB

• Pll: Yes
• Input: Clock
• Output: CMOS
• Number Of Circuits: 1
• Ratio - Input:output: 2:2
• Differential - Input:output: No/No
• Frequency - Max: 1.268GHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 2.8 V ~ 3.2 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 36-LLP
• Frequency-max: 1.268GHz
• For Use With: LMX25311226EVAL - BOARD EVAL FOR LMX25311226
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LMX2531LQE1226ETR

2.7 REGISTER R6
2.7.1 C3_C4_ADJ[2:0] -- VALUE FOR C3 AND C4 IN THE INTERNAL LOOP FILTER
2.7.2 R3_ADJ_FL[1:0] -- Value for Internal Loop Filter Resistor R3 During Fastlock
2.7.3 R3_ADJ[1:0] -- Value for Internal Loop Filter Resistor R3
2.7.4 R4_ADJ_FL[1:0] -- Value for Internal Loop Filter Resistor R4 During Fastlock
2.7.5 R4_ADJ[1:0] -- Value for Internal Loop Filter Resistor R4
2.7.6 EN_LPFLTR-- Enable for Partially Integrated Internal Loop Filter
The Enable Loop Filter bit is used to enable or disable the 3rd and 4th pole on-chip loop filters.
C3_C4_ADJ
0
1
2
3
4
5
6
7
R3_ADJ_FL Value
EN_LPFLTR
R4_ADJ_FL
R3_ADJ
R4_ADJ
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
C3 (pF)
100
150
100
(R3 = R4 = 0 Ω and C3 + C4 = 200pF)
50
50
50
50
50
29
R3 Resistor During Fastlock (kΩ)
3rd and 4th Poles of Loop Filter
R4 Value during Fast Lock (kΩ)
R4 Value ( kΩ )
R3 Value (kΩ)
disabled
enabled
10
20
30
40
10
20
30
40
10
20
30
40
10
20
30
40
C4 (pF)
100
150
100
150
150
50
50
50
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