SBOS817I June   2017  – August 2021 TLV6741 , TLV6742

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 for Single Channel
    5. 7.5 Thermal Information for Dual Channel
    6. 7.6 Electrical Characteristics
    7. 7.7 TLV6741: Typical Characteristics
    8. 7.8 TLV6742: Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 THD+ Noise Performance
      2. 8.3.2 Operating Voltage
      3. 8.3.3 Rail-to-Rail Output
      4. 8.3.4 EMI Rejection
      5. 8.3.5 Electrical Overstress
      6. 8.3.6 Typical Specifications and Distributions
      7. 8.3.7 Shutdown Function
      8. 8.3.8 Packages With an Exposed Thermal Pad
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Single-Supply Electret Microphone Preamplifier With Speech Filter
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.2.2 Detailed Design Procedure

The transfer function defining the relationship between VOUT and the AC input signal is shown in Equation 1:

Equation 1. GUID-56368F04-7214-49D3-AB89-DBDAF04E7BF2-low.gif

The required gain can be calculated based on the expected input signal level and desired output level as shown in Equation 2:

Equation 2. GUID-DECC07C6-07BC-4F05-8F65-C8921E110AF3-low.gif

Select a standard 10-kΩ feedback resistor and calculate RG.

Equation 3. GUID-3384A3B4-2B7C-417B-947D-5F28C3F94EB8-low.gif

To minimize the attenuation in the desired passband from 300 Hz to 3 kHz, set the upper (fH) and lower (fL) cutoff frequencies outside of the desired bandwidth as:

Equation 4. fL = 200 Hz

and

Equation 5. fH = 5 kHz

Select CG to set the fL cutoff frequency using Equation 6:

Equation 6. GUID-37BEE925-3093-4560-BFAD-28B9F3C25915-low.gif

Select CF to set the fH cutoff frequency using Equation 7:

Equation 7. GUID-49C45AAD-8768-480F-A012-EEEF15F3FE04-low.gif

The input signal cutoff frequency should be set low enough such that low-frequency sound waves still pass through. Therefore select CIN to achieve a 30-Hz cutoff frequency (fIN) using Equation 8:

Equation 8. GUID-C2437046-DF63-47EC-886C-19D28EA653FD-low.gif

The measured transfer function for the microphone preamplifier circuit is shown in Figure 9-2 and the measured THD+N performance of the microphone preamplifier circuit is shown in Figure 9-3.