LTC6400-20 1.8GHz Low Noise, Low Distortion Differential ADC Driver for 300MHz IF FEATURESDESCRIPTION ■ 1.8GHz –3dB Bandwidth The LTC®6400-20 is a high-speed differential amplifi er ■ Fixed Gain of 10V/V (20dB) targeted at processing signals from DC to 300MHz. The ■ –94dBc IMD3 at 70MHz (Equivalent OIP3 = 51dBm) part has been specifi cally designed to drive 12-, 14- and ■ –65dBc IMD3 at 300MHz (Equivalent OIP3 = 36.5dBm) 16-bit ADCs with low noise and low distortion, but can also ■ 1nV/√Hz Internal Op Amp Noise be used as a general-purpose broadband gain block. ■ 2.1nV/√Hz Total Input Noise The LTC6400-20 is easy to use, with minimal support ■ 6.2dB Noise Figure circuitry required. The output common mode voltage is ■ Differential Inputs and Outputs set using an external pin, independent of the inputs, which ■ 200Ω Input Impedance eliminates the need for transformers or AC-coupling ca- ■ 2.85V to 3.5V Supply Voltage pacitors in many applications. The gain is internally fi xed ■ 90mA Supply Current (270mW) at 20dB (10V/V). ■ 1V to 1.6V Output Common Mode Voltage, Adjustable The LTC6400-20 saves space and power compared to ■ DC- or AC-Coupled Operation alternative solutions using IF gain blocks and transform- ■ Max Differential Output Swing 4.4V ers. The LTC6400-20 is packaged in a compact 16-lead P-P ■ Small 16-Lead 3mm × 3mm × 0.75mm QFN Package 3mm × 3mm QFN package and operates over the –40°C to 85°C temperature range. APPLICATIONS , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ Differential ADC Driver ■ Differential Driver/Receiver ■ Single Ended to Differential Conversion ■ IF Sampling Receivers ■ SAW Filter Interfacing TYPICAL APPLICATIONEquivalent Output IP3 vsSingle-Ended to Differential ADC DriverFrequency 60 3.3V (NOTE 7) 1.25V 50 0.1μF 1000pF 0.1μF 40 V+ 0.1μF VOCM 30 10Ω V INPUT +IN CM VDD +OUT AIN+ +OUTF 20 66.5Ω OUTPUT IP3 (dBm) LTC6400-20 LTC2208 0.1μF –OUTF –IN –OUT AIN– 10 V– 10Ω 29Ω ENABLE LTC2208 130Msps 0 20dB GAIN 16-Bit ADC 0 50 100 150 200 250 300 FREQUENCY (MHz) 640020 TA01a 640020 TA01b 640020f 1