LMX2541SQE3030E/NOPB National Semiconductor, LMX2541SQE3030E/NOPB Datasheet - Page 32

• Manufacturer Part Number: LMX2541SQE3030E/NOPB
• Description: IC PLL FREQ SYNTH W/VCO 36LLP
• Manufacturer: National Semiconductor
• Series: PowerWise®r
• Type: Clock/Frequency Synthesizer (RF)r

Specifications of LMX2541SQE3030E/NOPB

• Pll: Yes
• Input: Clock
• Output: Clock
• Number Of Circuits: 1
• Ratio - Input:output: 2:2
• Differential - Input:output: No/No
• Frequency - Max: 3.23GHz
• 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: 3.23GHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LMX2541SQE3030ETR

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ExtVCOin (NOT OSCin) INPUT SENSITIVITY TEST SETUP
In order to measure the ExtVCOin Input sensitivity, the part is
put in External VCO mode and a signal is applied to the ExtV-
COin pin. A matching network, which is typically a 3 dB pad,
is used and this loss is added to the measured numbers as
well as any potential cable losses (on the order of 1 dB). A
signal is applied at a known frequency and power and the
output of the N counter is monitored using the Ftest/LD pin
and setting it to look at the N counter output divided by 2.
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Typically, the divide by 2 function is better because if it is not
used, the duty cycle from the Ftest/LD pin is not 50% and this
can sometimes confuse frequency counters. The part is set
in fractional mode with a large fraction of 502 +
2097150/4194301 to ensure that the fractional circuitry gets
fully tested. Accounting for the extra divide by 2 from the Ftest/
LD pin, the divided output frequency should be the input fre-
quency divided by 1005 to a 1 ppm tolerance.
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