LMX25313010EVAL National Semiconductor, LMX25313010EVAL Datasheet - Page 4

• Manufacturer Part Number: LMX25313010EVAL
• Description: BOARD EVAL FOR LMX25131LQ 3010
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LMX25313010EVAL

• Main Purpose: Timing, Frequency Synthesizer
• Embedded: No
• Utilized Ic / Part: LMX2531LQ3010
• Primary Attributes: Low Band 1455 - 1566 MHz, High Band 2910 - 3132 MHz
• Secondary Attributes: 2.8 V ~ 3.2 V Supply
• Silicon Manufacturer: National
• Silicon Core Number: LMX2531
• Kit Application Type: Clock & Timing
• Application Sub Type: Frequency Synthesizer
• Kit Contents: Board, Cable, CD
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Troubleshooting
LPT or USB Mode
LPT Mode (Uses Parallel Port Cable)
USB Mode (Uses USB <--> uWire Interface Board, NSID = USB2UWIRE)
Close-in phase noise is worse than evaluation board instructions
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Part responds to programming, but does not lock to the correct
Software does not communicate with the evaluation boards
Ensure a valid signal is presented to the OSCin connector. If a signal generator is used,
ensure the RF is ON.
Consult the CodeLoader instructions for more detailed information on communication issues.
Ensure that CodeLoader is selected to LPT mode on the Port Setup tab
Ensure the proper port number is selected (LPT1, LPT2, LPT3). CodeLoader does NOT
automatically detect this.
Ensure the LPT cable is securely connected to the computer and board.
Exit and Restart CodeLoader.
Ensure the parallel port is in the correct mode.
On the menu, select LPT/USB->Version to verify communication with the board.
Ensure the Green LEDs are lit on the USB board.
Ensure there are no conflicts with other USB devices and reinstall the board.
Ensure that there is a valid signal presented to the OSCin connector. If a signal generator is
used, ensure that the RF is set to ON.
If using the lower frequency band (DIV2=1), the VCO frequency in CodeLoader should be
twice the frequency at the Fout pin.
Ensure that the VCO FREQUENCY CAL bits on the Bits/Pins tab are correct.
Ensure that the loop filter is optimized if the charge pump current, phase detector frequency, or
loop filter values have been changed from their original settings. Ensure that the integrated
loop filter components on CodeLoader are set to their proper settings.
Ensure the signal presented to OSCin connector is clean. Try another source, or if it is a
signal generator, try using a higher frequency and dividing it down to the phase detector
frequency.
Ensure the OSCin signal after the connecting cable provides sufficient power level.
If the phase detector frequency or charge pump current are lowered from their original settings,
the in-band phase noise can be degraded, even if the loop filter is re-designed for the same
loop bandwidth.
If the loop bandwidth is decreased, in-band phase noise can be degraded
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Windows often requires Administrative access to write to the parallel port.
Ensure that the parallel port is set to “Enabled” in windows device manager.
A reboot upon installation of CodeLoader is sometimes necessary to get the parallel
port to work.
Standard mode is the most reliable. This can be set in the BIOS mode of the
computer as “Normal”, “Output Only”, or “AT.”
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E V A L U A T I O N
frequency
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