August 16, 2012 – Linear Technology Korea (CEO Hong Sa-gwak, www.linear.com) announced the launch of a fully differential buffer amplifier (product name: LTC6417) with output referred noise of only 1.5nV/√Hz. The LTC6417 can drive differential 50Ohm loads and is optimized for driving 14 and 16-bit pipeline ADCs. This product can be coupled via DC or AC at the input terminal and achieves excellent distortion performance at signals exceeding 600MHz maximum. At 140MHz, the OIP3 is 46dBm and HD3 is -69dBc, providing 50Ohm load characteristics with 2.4 VP-P output swing.

In addition to excellent performance specifications, the LTC6417 offers various features designed to simplify ADC interfacing. The LTC6417 can be configured as a unity-gain buffer. With input impedance of 18.5kOhm, additional gain can be achieved by applying a 1:4 or 1:8 transformer at the input terminal. The low impedance output supports capacitive charge injection management for pipeline ADCs. Since fast output clamping can be programmed with a single pin, it prevents ADC overrange conditions. When the clamp limits output voltage, the overrange pin sends a signal. The output common mode pin easily matches the LTC6417 output swing with the ADC input range.

The LTC6417 operates from a single 5V power supply. With the PWRADJ pin, designers can optimize HD3 performance and power consumption. This feature dramatically reduces supply current from 123mA to 74mA, and shutdown mode reduces current consumption to 24mA.

The LTC6417 is offered in a 3mm x 4mm 20-pin QFN package enabling easy use of flow-through pinout functionality. This product is optimized for operating ranges of 0°C to 70°C and -40°C to 105°C (case temperature). Starting at $3.89 per unit based on 1,000 unit quantity. For detailed information, refer to www.linear.com/product/LTC6417.

Photo Caption: Fully Differential Buffer Directly Driving 50Ohms

Product Features: LTC6417
• 1.6GHz –3dB small signal bandwidth
• 50Ohm load drive with low distortion, 2.4VP-P Out
o –100dBc/–69dBc HD2/HD3 at 140MHz
o –80dBc IM3 & 46dBm OIP3 at 140MHz
o –100dBc/–66dBc HD2/HD3 at 380MHz
o –68dBc IM3 & 39dBm OIP3 at 380MHz
• 1.5nV/√Hz output noise
• 4.3pA/√Hz input current noise
• Programmable fast, quick recovery output clamping
• 4.28VP-P maximum output swing
• DC-coupled signal path
• Single supply operation from 4.75V to 5.25V
• Power: reducible from 615mW to 370mW at 5V, shutdown mode 120mW
• 3mm x 4mm 20-pin QFN package