Features Very Low RMS Noise and Spurs • -225 dBc/Hz Normalized PLL Phase Noise • Integrated RMS Noise (100 Hz - 20 MHz) • 2 mrad (100 Hz - 20 MHz) at 2.1 GHz • 3.5 mrad (100 Hz - 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 • Analog and Digital Lock Detect • 1.6 V Logic Compatibility Description The LMX2541 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. The LMX2541 integrates several low-noise, high precision LDOs and output driver matching network to provide higher supply noise immunity and more consistent performance, while reducing the number of external components. When combined with a high quality reference oscillator, the LMX2541 generates a very stable, ultra low noise signal. The LMX2541 is offered in a family of 6 devices with varying VCO frequency range from 1990 MHz up to 4 GHz. Using a flexible divider, the LMX2541 can generate frequencies as low as 31.6 MHz. The LMX2541 is a monolithic integrated circuit, fabricated in a proprietary BiCMOS process. Device programming is facilitated using a three-wire MICROWIRE interface that can operate down to 1.6 volts. Supply voltage ranges from 3.15 to 3.45 volts. The LMX2541 is available in a 36 pin 6x6x0.8 mm Lead-Free Leadless Leadframe Package (LLP). Device VCO Frequency LMX2541SQ2060E 1990 - 2240 LMX2541SQ2380E 2200 - 2530 LMX2541SQ2690E 2490 - 2865 LMX2541SQ3030E 2810 - 3230 LMX2541SQ3320E 3130 - 3600 LMX2541SQ3740E 3480 - 4000

System Block Diagram MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application *click for larger image System Block Diagram	Block Diagram *click for larger image Functional Block Diagram
Typical Performance *click for larger image PLL Phase Noise

Datasheet

Title		Size	Date	Other Language
	LMX2541 Ultra-Low Noise PLLatinum Frequency Synthesizer with Integrated VCO	1652 Kbytes	23-Oct-09

Featured Application Notes

Title		Size	Date	Other Language
	AN-1558: Application Note 1558 Clocking High-Speed A/D Converters	659 Kbytes	17-Mar-07	日本語 中文

More Application Notes

Title		Size	Date	Other Language
	AN-1879: Application Note 1879 Fractional N Frequency Synthesis	511 Kbytes	10-Dec-08
	AN-1821: Application Note 1821 CPRI Repeater System	1497 Kbytes	15-May-08
	AN-1865: Application Note 1865 Frequency Synthesis and Planning for PLL Architectures	151 Kbytes	6-Feb-09

Design Tools

Title	Size	Date
LMX2541 Evaluation Board Instructions	1310 Kbytes	16-Sep-2009

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LMX2541SQ2060E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQ2380E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQ2690E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQ3030E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQ3320E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQ3740E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQE2060E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQE2380E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQE2690E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQE3030E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQE3320E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQE3740E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQX2060E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQX2380E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQX2690E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQX3030E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQX3320E	BICMOS8B+	0	1152	0	0	743900	5	211083656
LMX2541SQX3740E	BICMOS8B+	0	1152	0	0	743900	5	211083656

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

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