SLOS681C January   2011  – August 2019 DRV632

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Diagram
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Operating Characteristics
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Line Driver Amplifiers
      2. 9.3.2 Charge-Pump Flying Capacitor and PVSS Capacitor
      3. 9.3.3 Decoupling Capacitors
      4. 9.3.4 Gain-Setting Resistor Ranges
      5. 9.3.5 Input-Blocking Capacitors
      6. 9.3.6 DRV632 UVP Operation
      7. 9.3.7 External Undervoltage Detection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Using the DRV632 as a Second-Order Filter
      2. 9.4.2 Mute Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Charge-Pump Flying, PVSS and Decoupling Capacitors
        2. 10.2.2.2 Second-Order Active Low-Pass Filters
        3. 10.2.2.3 UVP Resistor Divider
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Gain-Setting Resistors
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Development Support
    2. 13.2 Community Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

9.4.1 Using the DRV632 as a Second-Order Filter

Several audio DACs used today require an external low-pass filter to remove out-of-band noise. This is possible with the DRV632, as it can be used like a standard operational amplifier. Several filter topologies can be implemented, both single-ended and differential. In Figure 8, multi-feedback (MFB) with differential input and single-ended input are shown.

An ac-coupling capacitor to remove dc content from the source is shown; it serves to block any dc content from the source and lowers the dc gain to 1, helping to reduce the output dc offset to a minimum.

To calculate the component values, use the TI WEBENCH® Filter Designer (www.ti.com/filterdesigner).

DRV632 lowpass_flt_LOS681.gifFigure 8. Second-Order Active Low-Pass Filter

The resistor values should have a low value for obtaining low noise, but should also have a high enough value to get a small-size ac-coupling capacitor. With the proposed values of R1 = 15 kΩ, R2 = 30 kΩ, and R3 = 43 kΩ, a dynamic range (DYR) of 106 dB can be achieved with a 1-μF input ac-coupling capacitor.