SBOS772C August   2017  – May 2019 INA1650-Q1 , INA1651-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
    1.     Simplified Internal Schematic
  3. 3 Description
    1.     CMRR Histogram (5746 Channels)
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions: INA1650-Q1
    2.     Pin Functions: INA1651-Q1
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics:
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Audio Signal Path
      2. 7.3.2 Supply Divider
      3. 7.3.3 EMI Rejection
      4. 7.3.4 Electrical Overstress
      5. 7.3.5 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Single-Supply Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Input Common-Mode Range
      2. 8.1.2 Common-Mode Input Impedance
      3. 8.1.3 Start-Up Time in Single-Supply Applications
      4. 8.1.4 Input AC Coupling
      5. 8.1.5 Supply Divider Capacitive Loading
    2. 8.2 Typical Applications
      1. 8.2.1 Line Receiver for Differential Audio Signals in a Split-Supply System
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Two-Channel Microphone Input for Automotive Infotainment Systems
      3. 8.2.3 TRS Audio Interface in Single-Supply Applications
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 TINA-TI (Free Software Download)
        2. 11.1.1.2 TI Precision Designs
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.1 Audio Signal Path

Figure 39 highlights the basic elements present in the audio signal pathway of the INA165x-Q1 line receivers. The primary elements are input biasing resistors, electromagnetic interference (EMI) filtering, input buffers, and a difference amplifier. The primary role of an audio line receiver is to convert a differential input signal into a single-ended output signal while rejecting noise that is common to both inputs (common-mode noise). The difference amplifier (which consists of an op amp and four matched 10-kΩ resistors) accomplishes this task. The basic transfer function of the circuit is shown in Equation 1:

Equation 1. INA1650-Q1 INA1651-Q1 FBD_eq_001.gif
INA1650-Q1 INA1651-Q1 FD_D001.gifFigure 39. INA165x-Q1 Audio Signal Path (Single Channel Shown)

The input buffers prevent external resistances (such as those from the PCB, connectors, or cables) from ruining the precise matching of the internal 10-kΩ resistors that degrade the high common-mode rejection of the difference amplifier. As is typical of many amplifiers, a small bias current flows into or out of the buffer amplifier inputs. This current must flow to a common potential for the buffer to function properly. The input biasing resistors provide an internal pathway for this current to the COM pin. The COM pin connects to ground in a dual-supply system, or to the output of the internal supply divider, VMID(OUT), in single-supply applications. Finally, EMI filtering is added to the input buffers to prevent high-frequency interference signals from propagating through the audio signal pathway.