LMK04000BEVAL/NOPB National Semiconductor, LMK04000BEVAL/NOPB Datasheet - Page 44

• Manufacturer Part Number: LMK04000BEVAL/NOPB
• Description: BOARD EVAL PRECISION CLOCK PLL
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LMK04000BEVAL/NOPB

• Main Purpose: Timing, Clock Conditioner
• Embedded: No
• Utilized Ic / Part: LMK04000
• Primary Attributes: 122.88 MHz VCXO
• Secondary Attributes: Integrated PLL & VCO
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LMK04000BEVAL; LMK04000BEVAL

Appendix G: VCXO/Crystal changes
This appendix contains instructions for changing the active on-board oscillator for PLL1.
Changing from Crystal Resonator to VCXO
If the board has been setup to use the crystal-based oscillator with PLL1, the crystal may be
disabled and the VCXO enabled as described on the following pages:
Summary
Procedures
Figure 19
1. Connect power to VCXO
2. Disconnect Crystal RF path and connect VCXO RF path
3. Connect charge pump output from PLL1 to VCXO Loop Filter (A1) and VCXO.
4. Connect charge pump output from PLL2 to VCXO Loop filter (A2).
1. Connect power to VCXO
a. Install a 0 ohm resistor in R26 (near the VCXO)
L M K 0 4 0 X X - R E V 3
E V A L U A T I O N
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