SLVSD80D November   2015  – May 2021 TPS65235

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  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 Timing Requirements
    7. 6.7 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  Boost Converter
      2. 7.3.2  Linear Regulator and Current Limit
      3. 7.3.3  Boost Converter Current Limit
      4. 7.3.4  Charge Pump
      5. 7.3.5  Slew Rate Control
      6. 7.3.6  Short Circuit Protection, Hiccup and Overtemperature Protection
      7. 7.3.7  Tone Generation
      8. 7.3.8  Tone Detection
      9. 7.3.9  Disable and Enable
      10. 7.3.10 Component Selection
        1. 7.3.10.1 Boost Inductor
        2. 7.3.10.2 Capacitor Selection
        3. 7.3.10.3 Surge Components
        4. 7.3.10.4 Consideration for Boost Filtering and LNB Noise
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
      1. 7.5.1 Serial Interface Description
      2. 7.5.2 TPS65235 I2C Update Sequence
    6. 7.6 Register Maps
      1. 7.6.1 Control Register 1 (address = 0x00H) [reset = 00010000]
      2. 7.6.2 Control Register 2 (address = 0x01H) [reset = 0000101]
      3. 7.6.3 Status Register (address = 0x02H) [reset = x0100000]
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application for DiSEqc1.x Support
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
      4. 8.2.4 Typical Application for DiSEqc2.x Support
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
        3. 8.2.4.3 Application Curves
  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 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2 Linear Regulator and Current Limit

The linear regulator is used to generate the 22-kHz tone signal by changing the LDO reference voltage. The linear regulator features low drop out voltage to minimize power loss while keeps enough head room for the 22-kHz tone with 650-mV amplitude. It also implements a tight current limit for overcurrent protection. The current limit is set by an external resistor connected to ISET pin. Figure 7-1 shows the relationship between the current limit threshold and the resistor value.

GUID-79D3FE33-E99D-42E8-85C2-A2DCD4D4208D-low.gifFigure 7-1 Linear Regulator Current Limit Vs Resistor
Equation 1. GUID-3D1E569E-82CD-420B-B684-9911FCEE37D5-low.gif

A 200-kΩ resistor sets the current to be 0.65 A, and 110-kΩ resistor sets the current to approximately 1 A.