LMX2430EVAL National Semiconductor, LMX2430EVAL Datasheet - Page 7

• Manufacturer Part Number: LMX2430EVAL
• Description: EVALUATION BOARD FOR LMX2430
• Manufacturer: National Semiconductor
• Series: PLLatinum™r

Specifications of LMX2430EVAL

• Main Purpose: Timing, Frequency Synthesizer
• Utilized Ic / Part: LMX2430
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / Rohs Status: Not Compliant
• Other names: *LMX2430EVAL

LMX2430SLE EVALUATION BOARD OPERATING INSTRUCTIONS
2.4
Lock Time Measurement Using A Modulation Domain Analyzer
The modulation domain analyzer measures the switching speed, or lock time, using a frequency
versus time plot. The modulation domain analyzer was used for the IF lock time measurement.
Set the center frequency of the modulation domain analyzer to the final (settling) frequency. Use
a wide span allows viewing of the entire positive or negative switching waveform. Use a narrower
span to evaluate the settling waveform within +/- 1 kHz. A trigger condition, typically a latch
enable pulse, specifies the event that will cause the modulation domain analyzer to capture and
display the measurement results. The lock time is the time difference between the point the
frequency starts to change (T1), and the point the VCO frequency settles to within +/-1 kHz of the
final value (T2), (i.e. lock time = T2 – T1).
Use the BurstMode tab of the CodeLoader software to program the device to toggle between a
desired minimum and maximum frequency. It is necessary to include a sufficient delay, such as
100000, after each programming command. For more detail, refer to the BurstMode Tab section
in the CodeLoader 2 Operating Instructions from National Semiconductor’s Wireless
Communications website: http://wireless.national.com/.
5
LMX2430SLEFPEB
February 3,2006