LMX2541SQE2060E/NOPB National Semiconductor, LMX2541SQE2060E/NOPB Datasheet - Page 14

• 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

Divider Noise Floor vs. Divider Value
(f
= 3700 MHz, Various values for VCO_DIV)
VCO
30073326
When the divider is engaged (VCO_DIV >0), then the entire system phase noise is reduced by a factor of 20 × log(VCO_DIV). However, the noise floor of the
divider will also add to this noise as is visible at far offsets. Note that the noise floor for Bypass mode is lower because the VCO divider is not engaged.
Divider Noise Floor vs. Frequency
30073313
Provided the VCO divider is not bypassed, the actual value of it does not impact the divider noise floor; it is the frequency at the RFout pin that impacts the divider
noise floor. The above plot shows how this noise floor changes as a function of the frequency of the RFout pin.
www.national.com
14