TIDUEV2 October   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Differences Between Audio DACs and Precision DACs
      2. 2.2.2 Right-Justified I2S to Daisy-Chained SPI Conversion
    3. 2.3 Highlighted Products
      1. 2.3.1 DAC11001
      2. 2.3.2 OPA1656
      3. 2.3.3 OPA1622
      4. 2.3.4 OPA2828
    4. 2.4 System Design Theory
      1. 2.4.1 Output Glitch
      2. 2.4.2 Sample Rate Dependence in Precision DACs
      3. 2.4.3 System Noise
      4. 2.4.4 DAC11001A vs DAC11001B
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 Required External Power Supplies
      2. 3.1.2 Jumper Definitions
      3. 3.1.3 Selecting I2S Source
        1. 3.1.3.1 USB I2S Source
        2. 3.1.3.2 SPDIF I2S Source
        3. 3.1.3.3 External PSIA I2S Source
    2. 3.2 Software Requirements
      1. 3.2.1 Installing the XMOS USB 2.0 Driver
      2. 3.2.2 Setting USB Sample Rate
    3. 3.3 Testing and Results
      1. 3.3.1 Measuring Total Harmonic Distortion and Noise
      2. 3.3.2 THD and THD+N Results
      3. 3.3.3 Measuring Dynamic Range
      4. 3.3.4 Dynamic Range Results
      5. 3.3.5 Measuring Signal-to-Noise Ratio
      6. 3.3.6 SNR Results
  10. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  11. 5Related Documentation
    1. 5.1 Support Resources
    2. 5.2 Trademarks
  12. 6About the Author

2.3.3 OPA1622

The OPA1622, dual, bipolar-input, SoundPlus™ audio operational amplifier achieves a very low, 2.8nV/√Hz noise density with an ultra-low THD+N of –119.2dB at 1kHz, while driving a 32Ω load at 100mW output power. The OPA1622 offers extremely high ac PSRR and CMRR specifications that eliminate noise from power supplies, making the OPA1622 an excellent choice for portable-audio applications. This device also has a high output-drive capability of +145mA per –130mA.

The OPA1622 operates over a very wide supply range of ±2V to ±18V, on only 2.6mA of supply current per channel. The OPA1622 op amp is unity-gain stable and provides excellent dynamic behavior over a wide range of load conditions. The OPA1622 includes a shutdown mode, allowing the amplifiers to be switched from normal operation to a standby current that is typically less than 5µA. This shutdown feature is specifically designed to eliminate click and pop noise when transitioning into or out of shutdown mode.

The OPA1622 features a unique internal layout for lowest crosstalk, and freedom from interactions between channels, even when over-driven or overloaded. This device is specified from –40°C to +125°C.