LMX2531LQE1226E/NOPB National Semiconductor, LMX2531LQE1226E/NOPB Datasheet - Page 32

• 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

www.national.com
2.9 REGISTER R8
2.9.1 XTLMAN2 -- MANUAL CRYSTAL MODE SECOND ADJUSTMENT
This bit also adjusts the calibration timing for lock time. In the case that manual mode for XTLSEL is selected and the OSCin
frequency is greater than 40 MHz, this bit should be enabled, otherwise it should be 0.
2.9.2 LOCKMODE -- FREQUENCY CALIBRATION MODE
This bit controls the method for which the VCO frequency calibration is done. The two valid modes are linear mode and mixed
mode. Linear mode works by searching through the VCO frequency bands in a consecutive manner. Mixed mode works by initially
using a divide and conquer approach and then using a linear approach. For small frequency changes, linear mode is faster and
for large frequency changes, mixed mode is faster. Linear mode can always be used, but there are restrictions for when Mixed
Mode can be used.
2.10 REGISTER R9
All the bits in this register should be programmed as shown in the programming table.
2.11 REGISTER R12
Even though this register does not have user selectable bits, it still needs to be programmed. This register should be loaded as
shown the Complete Register Content Map (section 2.03) .
LOCKMODE
0
1
2
3
LMX2531LQ2080E
LMX2531LQ2570E
LMX2531LQ2820E
LMX2531LQ3010E
Linear Mode
Description
Mixed Mode
Reserved
Reserved
Device
Kbit Values for Various LMX2531 options
LMX2531LQ1146E/1226E/1312E/1415E/1515E
All but the following options
Conditions on Options
Works over all options and all valid OSCin Frequencies
32
Never use this mode
Never use this mode
Conditions on OSCin Frequency
Kbit
4.5
6
7
8
f
OSCin
≥
8 MHz