LTC6948 Ultralow Noise 0.37GHz to 6.39GHz Fractional-N Synthesizer with Integrated VCO Fea T Descrip T n Low Noise Fractional-N PLL with Integrated VCO The LTC 6948 is a high performance, low noise, 6.39GHz n No - Modulator Spurs phase-locked loop (PLL) with a fully integrated VCO, n 18-Bit Fractional Denominator including a reference divider, phase-frequency detector n 226 dBc/Hz Normalized In-Band Phase Noise Floor (PFD), ultralow noise charge pump, fractional feedback n 274 dBc/Hz Normalized In-Band 1/f Noise divider, and VCO output divider. n 157 dBc/Hz Wideband Output Phase Noise Floor The fractional divider uses an advanced, 4th order n Excellent Integer Boundary Spurious Performance modulator which provides exceptionally low spurious n Output Divider (1 to 6, 50% Duty Cycle) levels. This allows wide loop bandwidths, producing n Output Buffer Muting extremely low integrated phase noise values. n Reference Input Frequency Up to 425MHz n The programmable VCO output divider, with a range of 1 Fast Frequency Switching n through 6, extends the output frequency range. FracNWizard Software Design Tool Support Output Frequency Options a T LTC6948-1 LTC6948-2 LTC6948-3 LTC6948-4 n O DIV = 1 2.240 to 3.740 3.080 to 4.910 3.840 to 5.790 4.200 to 6.390 Wireless Basestations (LTE, WiMAX, W-CDMA, PCS) n O DIV = 2 1.120 to 1.870 1.540 to 2.455 1.920 to 2.895 2.100 to 3.195 Microwave Data Links n O DIV = 3 0.747 to 1.247 1.027 to 1.637 1.280 to 1.930 1.400 to 2.130 Military and Secure Radio n O DIV = 4 0.560 to 0.935 0.770 to 1.228 0.960 to 1.448 1.050 to 1.598 Test and Measurement O DIV = 5 0.448 to 0.748 0.616 to 0.982 0.768 to 1.158 0.840 to 1.278 L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and FracNWizard is a trademark of Analog Devices, Inc. All other trademarks are the property of O DIV = 6 0.373 to 0.623 0.513 to 0.818 0.640 to 0.965 0.700 to 1.065 their respective owners. Typical a T 6.3GHz Wideband Receiver 1.6nF 10H 76.8 5V LTC6948-4 Phase Noise, 15 3.3V 0.1F 76.8 f = 6236MHz 1F RF 2.4nF 90 1F 56nF 0.01F 100 0.01F 1F 1F 110 100MHz + REF BVCO STAT GND 120 51.1 CS CM A 130 SCLK CM 2.2F B SPI BUS LTC6948-4 SDI RMS NOISE = 0.412 CM C 140 RMS JITTER = 183fs SDO GND f = 50MHz PFD 0.1F LDO TB LOOP BW = 186kHz 3.3V + 150 V D TUNE INTN = 0 3.3V CPLE = 1 R = 2, f = 50MHz PFD 160 0.1F N = 84 TO 127.8 100 1k 10k 100k 1M 10M 40M 3.3V 3.3V 68nH 1F UNUSED OUTPUT LBW = 186kHz OFFSET FREQUENCY (Hz) O = 1 6946 TA01b AVAILABLE FOR OTHER USE 0.01F 68nH 0.1F 100pF 50 100pF f = 4200MHz TO 6390MHz IN 190.7Hz STEPS LO IF IF OUTPUT LO RF RF INPUT SIGNAL 6948 TA01a 6948fa 1 For more information www.linear.com/LTC6948 GND MUTE REF GND + V REF RF CP + + RF V CP + GND V RF + BB V VCO PHASE NOISE (dBc/Hz) ion pplica ions pplica ion uresLTC6948 a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW Supply Voltages + + + + V (V , V , V ) to GND ...............................3.6V REF RF D 28 27 26 25 24 23 + + V , V to GND .............................................5.5V CP VCO + 1 22 REF BVCO + Voltage on CP Pin .................GND 0.3V to V + 0.3V CP STAT 2 21 GND + Voltage on all other Pins ...........GND 0.3V to V + 0.3V CS 3 20 CM A Operating Junction Temperature Range, T (Note 2) SCLK 4 19 CM J 29 B GND SDI 5 18 CM LTC6948I ........................................... 40C to 105C C 6 17 SDO GND Junction Temperature, T ................................ 125C JMAX LDO 7 16 TB Storage Temperature Range .................. 65C to 150C + V 8 15 TUNE D 9 10 11 12 13 14 UFD PACKAGE 28-LEAD (4mm 5mm) PLASTIC QFN T = 125C, = 7C/W JMAX JCbottom EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB o r Der i n F Ma T