LMX2541SQE2690E Datasheet PDF - National

●General 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 normal ized 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

●■ 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

●Target Applications

●■ Wireless Infrastructure (UMTS, LTE, WiMax)

●■ Broadband Wireless

●■ Wireless Meter Reading

●■ Test and Measurement