LTC6417 1.6GHz Low Noise High Linearity Differential Buffer/16-Bit ADC Driver with Fast Clamp Fea T Descrip T n 1.6GHz 3dB Small Signal Bandwidth The LTC 6417 is a differential unity gain buffer that can n drive a 50 load with extremely low noise and excellent Low Distortion Driving 50 Load, 2.4V Out P-P linearity. It is well suited for driving high speed 14- and 100dBc/69dBc HD2/HD3 at 140MHz 16-bit pipeline ADCs with input signals from DC to beyond 80dBc IM3 and 46dBm OIP3 at 140MHz 600MHz. Differential input impedance is 18.5k, allowing 100dBc/66dBc HD2/HD3 at 380MHz 1:4 and 1:8 transformers to be used at the input providing 68dBc IM3 and 39dBm OIP3 at 380MHz additional system gain in 50 systems. n 1.5nV/Hz Output Noise n 4.3pA/Hz Input Current Noise With no external biasing or gain setting components and n Programmable High Speed, Fast Recovery a flow-through pinout, the LTC6417 is very easy to use. It Output Clamping can be DC-coupled and has a common mode output offset n of 60mV. The LTC6417 input pins are internally biased to 4.28V Maximum Output Swing on a 50 P-P provide an output common mode voltage that is set by Differential Load n the voltage on the V pin for AC-coupled applications. DC-Coupled Signal Path CM n Operates on Single 4.75V to 5.25V Supply Supply current is typically 123mA and the LTC6417 operates n Power: 615mW on 5V, Can Be Reduced to 370mW, on supply voltages ranging from 4.75V to 5.25V. Power Shutdown Mode 120mW consumption can be reduced to 74mA via the PWRADJ n 3mm 4mm 20-Lead QFN Package pin. The LTC6417 also has a hardware shutdown feature which reduces current consumption to 24mA. The LTC6417 features fast, adjustable output voltage clamp- a T ing to help protect subsequent circuitry. The CLHI pin sets n Differential ADC Driver the maximum swing, while a symmetric minimum swing n CCD Buffer is set up internally. LTC6417 V pin will signal overrange OR n Cable Driver when the clamps limit output voltage. n 50 Buffer The LTC6417 is packaged in a 20-lead 3mm 4mm QFN L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear package. Pinout is optimized for placement directly adjacent Technology Corporation. All other trademarks are the property of their respective owners. to Linear Technologys high speed 14- and 16-bit ADCs. LTC6417 Driving LTC2209 Typical a T 16-Bit ADC 32K Point FFT, LTC6417 Driving an LTC2209 16-Bit ADC at 140MHz IF f = 140MHz, 1dBFS, PGA = 0 IN 3.3V 5V 0 HD2 = 88dBc C43 C45 10 E1 E3 HD3 = 94dBc 2.2F 27pF 18pF 680pF 0.1F 51nH 75nH 20 SFDR = 88dBc 1,6, SNR = 75.4dB 30 11,16 SEE FIGURE 1/TABLE 1 R36 R42 40 1:4 BALUN T1 + 5 60.4 300 10 V f = 153.6Msps 50 S WBC4-14LB 2 PWRADJ DEMO BOARD DC1685A 60 4 3 8 C40 + CLHI + IN 19 C41 R53 100 A IN 12pF 70 + E5 OUT 120 16 2 12pF 50 LTC2209 LTC6417 51nH 80 OUT 9 R12 C10 R43 A V IN 100 IN OR 18 90 + V CM 60.4 6 1 12pF 300 10 V PGA = 0 14 CM SHDN 100 GND 15 0.01F C44 C46 110 12 E2 E3 0.01F 1k 27pF 18pF 120 51nH 75nH CLOCK 3,7,10, 0 10 20 30 40 50 60 70 80 (153.6MHz) 17, 20,21 FREQUENCY (MHz) 6417 TA01b 6417 TA01a 2.2F 6417f 1 AMPLITUDE (dBFS) ion pplica ions pplica ion uresLTC6417 a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW + Total Supply Voltage (V to GND) .............................5.5V Input Current (CLHI, V ) .................................... 10mA CM + 20 19 18 17 Input Current (IN , IN ) ........................................30mA + + + V 1 16 V Output Current (OUT , OUT ) .............................100mA CLHI 2 15 V CM Output Current (V ) ........................................... 10mA OR GND 3 14 V OR 21 Operating Temperature Range GND NC 4 13 NC (T ) (Note 2) .......................................... 40C to 105C C PWRADJ 5 12 SHDN + + Specified Temperature Range V 6 11 V (T ) (Note 3) .......................................... 40C to 105C C 7 8 9 10 Storage Temperature Range .................. 65C to 150C Junction Temperature (T ) .............................. 150C JMAX UDC PACKAGE 20-LEAD (3mm 4mm) PLASTIC QFN T = 150C, = 52C/W, = 6.8C/W JMAX JA JC EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC6417CUDC PBF LTC6417CUDC TRPBF LFVN 0C to 70C 20-Lead (3mm 4mm) Plastic QFN LTC6417IUDC PBF LTC6417IUDC TRPBF LFVN 20-Lead (3mm 4mm) Plastic QFN 40C to 105C (T ) C *Temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on lead based finish parts. For more information on lead free part marking, go to: