LTC6945 Ultralow Noise and Spurious 0.35GHz to 6GHz Integer-N Synthesizer Fea T Descrip T n Low Noise Integer-N PLL The LTC 6945 is a high performance, low noise, 6GHz phase- n 350MHz to 6GHz VCO Input Range locked loop (PLL), including a reference divider, phase- n 226dBc/Hz Normalized In-Band Phase Noise Floor frequency detector (PFD) with phase-lock indicator, charge n pump, integer feedback divider and VCO output divider. 274dBc/Hz Normalized In-Band 1/f Noise n 157dBc/Hz Wideband Output Phase Noise Floor The part features a buffered, programmable VCO output n Excellent Spurious Performance divider with a range of 1 through 6. The differential, low n Output Divider (1 to 6, 50% Duty Cycle) noise output buffer has user-programmable output power n Low Noise Reference Buffer ranging from 6dBm to 3dBm, and may be muted through n Output Buffer Muting either a digital input pin or software. n Charge Pump Supply from 3.15V to 5.25V The low noise reference buffer outputs a typical 0dBm n Charge Pump Current from 250A to 11.2mA square wave directly into a 50 impedance from 10MHz n Configurable Status Output to 250MHz, or may be disabled through software. n SPI Compatible Serial Port Control n The ultralow noise charge pump contains selectable high PLLWizard Software Design Tool Support and low voltage clamps useful for VCO monitoring, and + also may be set to provide a V /2 bias. a T n All device settings are controlled through a SPI-compatible Wireless Base Stations (LTE, WiMAX, W-CDMA, PCS) n serial port. Broadband Wireless Access n Microwave Data Links L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and PLLWizard is a trademark of Linear Technology Corporation. All other trademarks are the n Military and Secure Radio property of their respective owners. n Test and Measurement Typical a T LTC6945 Data Converter Sample Clock 3.3V LOOP 5V BANDWIDTH CRYSTEK 0.1F V TUNE ~2.3kHz CVCSO-914-1000 1GHz Sample Clock Phase Noise 5V 100 432 47nF 51.1 100MHz DSB INTEGRATION 0.1F REF (100Hz TO 1GHz) 570nF 110 1F RMS NOISE = 0.014 1F RMS JITTER = 39fs 120 f = 25MHz PFD 3.3V 3.3V 0.01F + + + BW = 2.3kHz REF REF V CP V GND REF CP 130 + + V V REFO VCO 0.1F 140 REFO GND LTC6945 STAT GND 150 100pF CS GND GND 160 SCLK GND SPI BUS 16.5 SDI GND 16.5 170 + SDO V CO f = 25MHz PFD + 180 3.3V V V D CO 16.5 100 1k 10k 100k 1M 10M 40M + + 100pF 0.1F MUTE GND RF RF V BB RF OFFSET FREQUENCY (Hz) 1.0F 100pF 6945 TA01b 3.3V 0.01F SAMPLE CLOCK 68nH 3.3V 1GHz, 7dBm 100pF 68nH 6945 TA01b 3.3V 50 100pF ALT SAMPLE CLOCK 500MHz OR 1GHz 6945fa 1 For more information www.linear.com/LTC6945 PHASE NOISE (dBc/Hz) ion pplica ions pplica ion uresLTC6945 a Te Maxi Mu M r a T p c F T (Note 1) TOP VIEW Supply Voltages + + + + + + V (V , V , V , V , V ) to GND ......3.6V REF REFO RF VCO D + V to GND .........................................................5.5V 28 27 26 25 24 23 CP + + + V 1 22 V Voltage on CP Pin .................GND 0.3V to V + 0.3V REFO VCO CP + REFO 2 21 GND Voltage on All Other Pins ..........GND 0.3V to V + 0.3V STAT 3 20 GND Operating Junction Temperature Range, T (Note 2) J CS 4 19 GND 29 LTC6945I ............................................... 40C to 105C GND SCLK 5 18 GND Junction Temperature, T ................................ 125C JMAX SDI 6 17 GND + Storage Temperature Range .................. 65C to 150C SDO 7 16 VCO + V 8 15 VCO D 9 10 11 12 13 14 UFD PACKAGE 28-LEAD (4mm 5mm) PLASTIC QFN T = 125C, = 3C/W, = 26C/W JMAX JCbottom JCtop EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB o r D i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION JUNCTION TEMPERATURE RANGE LTC6945IUFD PBF LTC6945IUFD TRPBF 6945 28-Lead (4mm 5mm) Plastic QFN 40C to 105C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: