LTC6948
Ultralow Noise 0.37GHz to
6.39GHz Fractional-N Synthesizer
with Integrated VCO
Description Features Low Noise Fractional-N PLL with Integrated VCO
nn No ∆-∑ Modulator Spurs
nn 18-Bit Fractional Denominator
nn –226 dBc/Hz Normalized In-Band Phase Noise Floor
nn –274 dBc/Hz Normalized In-Band 1/f Noise
nn –157 dBc/Hz Wideband Output Phase Noise Floor
nn Excellent Integer Boundary Spurious Performance
nn Output Divider (1 to 6, 50% Duty Cycle)
nn Output Buffer Muting
nn Reference Input Frequency Up to 425MHz
nn Fast Frequency Switching
nn FracNWizardв„ў Software Design Tool Support The LTCВ®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. Applications Output Frequency Options nn Wireless Basestations (LTE, WiMAX, W-CDMA, PCS)
Microwave Data Links
nn Military and Secure Radio
nn Test and Measurement O_DIV = 1 2.240 to 3.740 3.080 to 4.910 3.840 to 5.790 4.200 to 6.390 nn O_DIV = 2 1.120 to 1.870 1.540 to 2.455 1.920 to 2.895 2.100 to 3.195 O_DIV = 3 0.747 to 1.247 1.027 to 1.637 1.280 to 1.930 1.400 to 2.130 O_DIV = 4 0.560 to 0.935 0.770 to 1.228 0.960 to 1.448 1.050 to 1.598 O_DIV = 5 0.448 to 0.748 0.616 to 0.982 0.768 to 1.158 0.840 to 1.278 O_DIV = 6 0.373 to 0.623 0.513 to 0.818 0.640 to 0.965 0.700 to 1.065 nn The fractional divider uses an advanced, 4th order Δ∑ …