LT1567 1.4nV/√Hz 180MHz Filter Building Block UFEATURESDESCRIPTIO ■ Single-Ended to Differential Conversion The LT®1567 is an analog building block optimized for ■ Low Noise: 1.4nV/ √ Hz very low noise high frequency filter applications. It con- ■ 20 µ V tains two wideband rail-to-rail operational amplifiers, one RMS Total Wideband Noise in Filterwith 2MHz f of them internally configured as a unity-gain inverter. C ■ Dynamic Range: 104dB SNR at ±5V With the addition of a few passive components, the ■ Total Supply Voltage: 2.7V to 12V LT1567 becomes a flexible second order filter section ■ Rail-to-Rail Outputs with cutoff frequency (fC) up to 5MHz, ideal for antialias- ■ DC Accurate: Op Amp V ing or for channel filtering in high speed data communi- OS 0.5mV (Typ) ■ Trimmed Bandwidth for Accurate Filters cations systems. A spreadsheet-based design tool is ■ No External Clock Required available at www.linear.com for designing lowpass and ■ MSOP-8 Surface Mount Package bandpass filters using the LT1567. U In addition to low noise and high speed, the LT1567 APPLICATIO S features single-ended to differential conversion for direct driving of high speed differential input A/D converters. The ■ Low Noise, High Speed Filters to 5MHz LT1567 operates from a total power supply voltage of 2.7V ■ Low Noise Differential Circuits to 12V and supports signal-to-noise ratios above 100dB. ■ Communication Channel or Roofing Filters ■ Antialias or Reconstruction Filtering The LT1567 is available in an 8-lead MSOP package. ■ Video Signal Processing , LTC, LT and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ Single-Ended to Differential Conversion UTYPICAL APPLICATIO2MHz 3-Pole Antialias Filter withSingle-Ended to Differential ConversionFrequency Response V+ 12 R2 0.1µF 536Ω 6 C2 R1 R3 270pF 0 536Ω 147Ω 1 8 R4 VIN 147Ω –6 +A 2 7 IN –12 C1 0.1µF C3 LT1567 ADC 270pF 3 6 270pF GAIN (dB) –18 –AIN 4 5 R5 –24 LTC1420 147Ω NOTE: 6dB GAIN RESULTS FROM 0.1µF –30 SINGLE-ENDED TO DIFFERENTIAL 1567 TA01 CONVERSION V– –36 100 1M 10M 96dB DIFFERENTIAL SNR WITH 3V TOTAL SUPPLY FREQUENCY (Hz) R2 GAIN = ≤ 2.5MHz R1 f 1567 TA01a –3dB R3 = R4 = R5, C1 = C2 = C3 1.82 f 1 –3dB = = ; f 2πR2C2 –3dB ≤ 2.5MHz 4πR3C3 1567fa 1