OP275 Bipolar/JFET, Audio Dual Op Amp

The OP275 is the first amplifier to feature the Butler Amplifier front-end. This new front-end design combines both bipolar and JFET transistors to attain amplifiers with the accuracy and low noise performance of bipolar transistors, and the speed and sound quality of JFET's. Total Harmonic Distortion plus Noise equals that of previous audio amplifiers, but at much lower supply currents.

A very low l/f corner of below 6 Hz maintains a flat noise density response. Whether noise is measured at either 30 Hz or 1kHz, it is only 6 nV/(root)Hz. The JFET portion of the input stage gives the OP275 its high slew rates to keep distortion low, even when large output swings are required, and the 22 V/µs slew rate of the OP275 is the fastest of any standard audio amplifier. Best of all, this low noise and high speed are accomplished using less than 5mA of supply current, lower than any standard audio amplifier.

Improved dc performance is also provided with bias and offset currents greatly reduced over purely bipolar designs. Input offset voltage is guaranteed at 1mV and is typically less than 200µV. This allows the OP275 to be used in many dc coupled or summing applications without the need for special selections or the added noise of additional offset adjustment circuitry.

The output os capable of driving 600 Ohm loads to 10 V rms while maintaining low distortion. THD + Noise at 3 V rms is a low 0.0006%.

The OP275 is specified over the extended industrial (-40°C to +85°C) temperature range. OP275s are availale in both plastic DIP and SOIC-8 packages. SOIC-8 packages are available in 2500 piece reels. Many audio amplifiers are not offered in SOIC-8 surface mount packages for a variety of reasons; however, the OP275 was designed so that it would offer full performance in surface mount packaging.

Features and Benefits
  • Excellent Sonic Characteristics
  • Low Noise: 6 nV/√Hz
  • Low Distortion: 0.0006%
  • High Slew Rate: 22 V/µs
  • Wide Bandwidth: 9 MHz
  • Low Supply Current: 5 mA
  • Low Offset Voltage: 1 mV
  • Low Offset Current: 2 nA
  • Unity Gain Stable
  • SOIC-8 Package
  • PDIP-8 Package
  • Amplifiers
    OP275 SPICE Macro-Model
    Data Sheets
    Documentnote
    OP275: Dual Bipolar/JFET, Audio Operational Amplifier Data Sheet (Rev. C)PDF 416 kB
    Application Notes
    Documentnote
    AN-356: User's Guide to Applying and Measuring Operational Amplifier SpecificationsPDF 538 kB
    AN-649: Using the Analog Devices Active Filter Design Tool (Rev. 0)PDF 5.3 M
    AN-211: The Alexander Current-Feedback Audio Power AmplifierPDF 1154 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    OP275GPZ Production8 ld PDIPOTH 50-40 to 85C1.281.15Y
    OP275GS Production8 ld SOICOTH 98-40 to 85C1.291.16N
    OP275GS-REEL Production8 ld SOICREEL 2500-40 to 85C01.16N
    OP275GS-REEL7 Production8 ld SOICREEL 1000-40 to 85C01.16N
    OP275GSZ Production8 ld SOICOTH 98-40 to 85C1.141.02Y
    OP275GSZ-REEL Production8 ld SOICREEL 2500-40 to 85C01.02Y
    OP275GSZ-REEL7 Production8 ld SOICREEL 1000-40 to 85C01.02Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    EVAL-PRAOPAMP-2CPZDual CP-8 lead LFCSP Evaluation Board20.19Y
    EVAL-PRAOPAMP-2RMZDual RM-8 lead MSOP Evaluation Board20.19Y
    EVAL-PRAOPAMP-2RZDual R-8 lead SOIC Evaluation Board20.19Y
    OP275: Dual Bipolar/JFET, Audio Operational Amplifier Data Sheet (Rev. C) op275
    OP275 SPICE Macro-Model Rev. C, 3/95 op275
    OP275G SPICE Macro-Model Rev. B, 10/92 op275
    AN-356: User's Guide to Applying and Measuring Operational Amplifier Specifications ad8350
    AN-356: 用户指南:运算放大器规格参数的应用和测量 (Rev. 0) ad8350
    AN-649: Using the Analog Devices Active Filter Design Tool (Rev. 0) ad8350
    AN-211: The Alexander Current-Feedback Audio Power Amplifier ad73311