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LMX2324
March 5, 1999
LMX2324 Evaluation Board Operating Instructions
General Description
The LMX2324 Evaluation Board simplifies the evaluation of the LMX2324 2.0GHz PLLatinum frequency
synthesizer. It enables all performance measurements, with no additional support circuitry.
The board consists of a LMX2324 device, a VCO module and a loop filter built by discrete components. The SMA
flange mount connectors are provided for external reference input, RF output and the power & grounding
connection. A cable assembly is bundled with the evaluation board for connecting to PC through the parallel
printer port. By means of uWire serial port emulation, the Code Loader software included can be run on PC to
facilitate the LMX2324 internal register programming for the evaluation and measurement.
Loop Filter Illustration
Type 2 third order passive loop filter configuration is employed on the LMX2324 evaluation board. The loop filter
was designed based on the assumption of 12kHz loop bandwidth, 50 degree phase margin, 200kHz reference
frequency, and 10dB of attenuation. The actual implementations are shown as below:
C1
C2
C3
R2
R3
DoRF
RF VCO
LOOP FILTER
C1 = 1200pF
C2 = 8200pF
R2= 4.7kohm
R3 = 15kohm
C3 = 120pF