The LMX2541 device is an ultra low-noise frequency synthesizer which integrates a high-performance delta-sigma fractional N PLL, a VCO with fully integrated tank circuit, and an optional frequency divider. The PLL offers an unprecedented normalized noise floor of –225 dBc/Hz and can be operated with up to 104 MHz of phase-detector rate (comparison frequency) in both integer and fractional modes. The PLL can also be configured to work with an external VCO.
Features
• Multiple Frequency Options Available (See Device Comparison Table)
• Frequencies From 31.6 MHz to 4000 MHz
• Very Low RMS Noise and Spurs
• –225 dBc/Hz Normalized PLL Phase Noise
• Integrated RMS Noise (100 Hz to 20 MHz)
– 2 mRad (100 Hz to 20 MHz) at 2.1 GHz
– 3.5 mRad (100 Hz to 20 MHz) at 3.5 GHz
• Ultra Low-Noise Integrated VCO
• External VCO Option (Internal VCO Bypassed)
• VCO Frequency Divider 1 to 63 (All Values)
• Programmable Output Power
• Up to 104-MHz Phase Detector Frequency
• Integrated Low-Noise LDOs
• Programmable Charge Pump Output
• Partially Integrated Loop Filter
• Digital Frequency Shift Keying (FSK) Modulation Pin
• Integrated Reference Crystal Oscillator Circuit
• Hardware and Software Power Down
• FastLock Mode and VCO-Based Cycle Slip Reduction
