DESCRIPTION

· The LTC6948 is a high-performance, low-noise, 6.39GHz phase-locked loop (PLL) with a fully integrated VCO.

· It includes a reference divider, phase-frequency detector (PFD), ultralow noise charge pump, fractional feedback divider, and VCO output divider.

· The fractional divider uses a 4th order Δ∑ modulator for exceptionally low spurious levels and wide loop bandwidths.

· The programmable VCO output divider extends the output frequency range from 1 to 6.

FEATURES

· Ultralow noise fractional-N PLL with integrated VCO.

· No Δ-∑ modulator spurs, 18-bit fractional denominator.

· Normalized in-band phase noise floor of -226 dBc/Hz, in-band 1/f noise of -274 dBc/Hz.

· Wideband output phase noise floor of -157 dBc/Hz, 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 applications.