DESCRIPTION
The LTC®6948 is a high performance, low noise, 6.39GHz phase-locked loop (PLL) with a fully integrated VCO, including a reference divider, phase-frequency detector (PFD), ultralow noise charge pump, fractional feedback divider, and VCO output divider.
The fractional divider uses an advanced, 4th order Δ∑ modulator which provides exceptionally low spurious levels. This allows wide loop bandwidths, producing extremely low integrated phase noise values.

FEATURES
■ Low Noise Fractional-N PLL with Integrated VCO
■ No ∆-∑ Modulator Spurs
■ 18-Bit Fractional Denominator
■ –226 dBc/Hz Normalized In-Band Phase Noise Floor
■ –274 dBc/Hz Normalized In-Band 1/f Noise
■ –157 dBc/Hz Wideband Output Phase Noise Floor
■ Excellent Integer Boundary Spurious Performance
■ Output Divider (1 to 6, 50% Duty Cycle)
■ Output Buffer Muting
■ Reference Input Frequency Up to 425MHz
■ Fast Frequency Switching
■ FracNWizard™ Software Design Tool Support

APPLICATIONS
■ Wireless Basestations (LTE, WiMAX, W-CDMA, PCS)
■ Microwave Data Links
■ Military and Secure Radio
■ Test and Measurement