LT1993-2 800MHz Low Distortion, Low Noise Differential Amplifier/ ADC Driver (AV = 2V/V) FEATURES DESCRIPTION n 800MHz –3dB Bandwidth The LT®1993-2 is a low distortion, low noise Differential n Fixed Gain of 2V/V (6dB) Amplifier/ADC driver for use in applications from DC to n Low Distortion: 800MHz. The LT1993-2 has been designed for ease of 38dBm OIP3, –70dBc HD3 (70MHz, 2VP-P) use, with minimal support circuitry required. Exceptionally 51dBm OIP3, –94dBc HD3 (10MHz, 2VP-P) low input-referred noise and low distortion products n Low Noise: 12.3dB NF, en = 3.8nV/√Hz (70MHz) (with either single-ended or differential inputs) make the n Differential Inputs and Outputs LT1993-2 an excellent solution for driving high speed n Additional Filtered Outputs 12-bit and 14-bit ADCs. In addition to the normal unfiltered n Adjustable Output Common Mode Voltage outputs (+OUT and –OUT), the LT1993-2 has a built-in n DC- or AC-Coupled Operation 175MHz differential low pass filter and an additional pair n Minimal Support Circuitry Required of filtered outputs (+OUTFILTERED, –OUTFILTERED) to n Small 0.75mm Tall 16-Lead 3 × 3 QFN Package reduce external filtering components when driving high speed ADCs. The output common mode voltage is easily APPLICATIONS set via the VOCM pin, eliminating either an output trans- former or AC-coupling capacitors in many applications. n Differential ADC Driver for: The LT1993-2 is designed to meet the demanding require- Imaging ments of communications transceiver applications. It can Communications be used as a differential ADC driver, a general-purpose n Differential Driver/Receiver differential gain block, or in any other application requir- n Single Ended to Differential Conversion ing differential drive. The LT1993-2 can be used in data n Differential to Single Ended Conversion acquisition systems required to function at frequencies n Level Shifting down to DC. n IF Sampling Receivers n SAW Filter Interfacing/Buffering The LT1993-2 operates on a 5V supply and consumes All registered trademarks and trademarks are the property of their respective owners. 100mA. It comes in a compact 16-lead 3 × 3 QFN package and operates over a –40°C to 85°C temperature range. TYPICAL APPLICATION 4-Tone WCDMA Waveform,4-Channel WCDMA Receive ChannelLT1993-2 Driving LTC2255 14-BitADC at 92.16Msps 0 32768 POINT FFT 1:4 0.1µF –10 TONE CENTER FREQUENCIES Z-RATIO 70MHz –20 AT 62.5MHz, 67.5MHz, –INB IF IN 12.2Ω 72.5MHz, 77.5MHz –OUT –30 • • –INA AIN– –OUTFILTERED –40 LTC2255 0.1 LT1993-2 82nH 52.3pF µF –50 ADC +OUTFILTERED –60 +INB AIN+ MINI-CIRCUITS +OUT –70 12.2Ω TCM4-19 +INA VOCM LTC2255 125Msps AMPLITUDE (dBFS) –80 ENABLE 14-BIT ADC SAMPLING –90 AT 92.16Msps 2.2V –100 –110 19932 TA01a –120 0 5 10 15 20 25 30 35 40 45 FREQUENCY (MHz) 19932 TA01b Rev B Document Feedback For more information www.analog.com 1
