SLVSEC4B April   2019  – January 2020 TPS92613-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Diagram
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Power Supply
        1. 7.3.1.1 Power-On Reset (POR)
        2. 7.3.1.2 Low-Quiescent-Current
      2. 7.3.2 Constant-Current Driver
      3. 7.3.3 PWM Control
      4. 7.3.4 Supply Control
      5. 7.3.5 Diagnostics and Protection
        1. 7.3.5.1 Open-Circuit Detection
        2. 7.3.5.2 Short-to-GND Detection
        3. 7.3.5.3 Overtemperature Protection
        4. 7.3.5.4 DIAGEN
        5. 7.3.5.5 Low-Dropout Operation
      6. 7.3.6 FAULT Bus Output With One-Fails–All-Fail
      7. 7.3.7 Fault Table
    4. 7.4 Device Functional Modes
      1. 7.4.1 Undervoltage Lockout, V(SUPPLY) < V(POR_rising)
      2. 7.4.2 Normal Operation V(SUPPLY) ≥ 4.5 V
      3. 7.4.3 Low-Voltage Dropout Operation
      4. 7.4.4 Fault Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Single-Channel LED Driver With Diagnostics
        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 Single-Channel LED Driver With Heat Sharing
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 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 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.5.5 Low-Dropout Operation

When the supply voltage drops below LED string total forward voltage plus V(DROPOUT) at required current, the TPS92613-Q1 device operates in low-dropout conditions to deliver current output as close as possible to target value. The actual current output is less than preset value due to insufficient headroom voltage for power transistor. As a result, the voltage across the sense resistor fails to reach the regulation target.

If the TPS92613-Q1 is designed to operate in low-dropout condition, and the open-circuit diagnostics must be disabled by pulling the DIAGEN pin voltage lower than VIL(DIAGEN). Otherwise, the TPS92613-Q1 detects an open-circuit fault and reports a fault indication on the FAULT pin. The DIAGEN pin is used to avoid false diagnostics due to low supply voltage.

In low-dropout operation, a diode in parallel with the sense resistor is recommended to clamp the voltage between SUPPLY and IN (across the sense resistor) in case of a large current pulse during recovery.