LTC6420-20 Dual Matched 1.8GHz Differential Amplifi ers/ADC Drivers FEATURESDESCRIPTION n Matched Gain ±0.1dB The LTC®6420-20 is a dual high-speed differential amplifi er n Matched Phase ±0.1° at 100MHz targeted at processing signals from DC to 300MHz. The n Channel Separation 80dB at 100MHz part has been specifi cally designed to drive 12-, 14- and n 1.8GHz –3dB Bandwidth; Fixed Gain of 10V/V (20dB) 16-bit ADCs with low noise and low distortion, but can also n IMD3 = –84dBc at 100MHz, 2VP-P be used as a general-purpose broadband gain block. n Equivalent OIP3 = 46dBm at 100MHz The LTC6420-20 is easy to use, with minimal support n 1nV/√Hz Internal Op Amp Noise circuitry required. The output common mode voltage n 6.2dB Noise Figure is set using an external pin, independent of the inputs, n Differential Inputs and Outputs which eliminates the need for transformers or AC-coupling n Rail-to-Rail Output Swing capacitors in many applications. The gain is internally n 80mA Supply Current (240mW) per Amplifi er fi xed at 20dB (10V/V). n 1.1V to 1.6V Output Common Mode Voltage, Adjustable The LTC6420-20 saves space and power compared to n DC- or AC-Coupled Operation alternative solutions using IF gain blocks and transformers. n 20-Lead 3mm × 4mm × 0.75mm QFN Package The LTC6420-20 is packaged in a compact 20-lead 3mm × 4mm QFN package and operates over the –40°C APPLICATIONS to 85°C temperature range. n Differential ADC Driver L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Single Ended to Differential Conversion n IF Sampling (Diversity) Receivers n Broadband I/Q Amplifi ers n Satellite Communications TYPICAL APPLICATIONMatched Dual Amplifi er with Output Common Mode BiasingDistribution of Gain Match 0.1μF 3V 40 1000pF VOCM A 35 30 V+ A VOCM A ENABLEA ZIN = 200Ω 1000Ω 25 0.1μF 100Ω – 12.5Ω 20 –IN A +OUT A UNITS (%) V 15 OCM A VIN A 0.1μF +IN A 100Ω 12.5Ω + 10 –OUT A VOCM A 1000Ω 5 V– V– ±0.1dB GAIN MATCHING LTC6420-20 0 1000Ω ±0.1° PHASE MATCHING AT 100MHz – 0.25 – 0.15 – 0.05 0.05 0.15 0.25 0.1μF CHANNEL-TO-CHANNEL GAIN MATCH (dB) 100Ω 12.5Ω 642020 TA01b +IN B + – OUT B V VIN B 0.1μF OCM B –IN B 100Ω 12.5Ω – +OUT B VOCM B 1000Ω ZIN = 200Ω V+ B VOCM B ENABLEB 0.1μF 1000pF VOCM B 642020 TA01a 3V 642020fb 1 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION SELECTOR GUIDE DC ELECTRICAL CHARACTERISTICS AC ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS
