LMX2541SQE2060E/NOPB National Semiconductor, LMX2541SQE2060E/NOPB Datasheet - Page 29

• Manufacturer Part Number: LMX2541SQE2060E/NOPB
• Description: IC PLL FREQ SYNTH W/VCO 36LLP
• Manufacturer: National Semiconductor
• Series: PowerWise®r
• Type: Clock/Frequency Synthesizer (RF)r

Specifications of LMX2541SQE2060E/NOPB

• Pll: Yes
• Input: Clock
• Output: Clock
• Number Of Circuits: 1
• Ratio - Input:output: 2:2
• Differential - Input:output: No/No
• Frequency - Max: 2.24GHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 3.15 V ~ 3.45 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 36-LLP
• Frequency-max: 2.24GHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LMX2541SQE2060ETR

RFout OUTPUT POWER TEST SETUP
The output power is tested by programming the VCO output
to a desired frequency and measuring with a spectrum ana-
lyzer. A 3 dB pad is used and this gain as well as any losses
from the cable are added to the actual measurement. As for
the DC blocking capacitor, typically 100 pF is used for fre-
quencies above 2 GHz and 0.1 uF are used for frequencies
below 2 GHz. It turns out that the measurement is not as sen-
sitive as one would expect to this blocking capacitor value.
(Note
6)
29
The output power is mainly a function of the frequency of the
output buffer and the settings of the VCO_DIV (1 or >1),
OUTTERM, VCOGAIN, and DIVGAIN bits. It is not very sen-
sitive to the actual frequency option of the part. For instance,
the LMX2541SQ2060E and the LMX2541SQ2380E both
should have similar output power at 2.2 GHz. Note that this
same test setup can also be used to measure harmonics.
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