SLVSGP5 may   2023 TPS92629-Q1

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 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 (SUPPLY)
        1. 7.3.1.1 Power-On Reset (POR)
        2. 7.3.1.2 Supply Current in Fault Mode
      2. 7.3.2  Enable and Shutdown
      3. 7.3.3  Constant-Current Output and Setting (IN)
      4. 7.3.4  Thermal Sharing Resistor (OUT and RES)
      5. 7.3.5  Brightness Control (EN/PWM and ADIM)
      6. 7.3.6  Diagnostics
        1. 7.3.6.1 LED Short-to-GND Detection
        2. 7.3.6.2 LED Open-Circuit and Short-to-Battery Detection
        3. 7.3.6.3 LED Open-Circuit and Short-to-Battery Detection Enable (DIAGEN)
        4. 7.3.6.4 Overtemperature Protection
        5. 7.3.6.5 Low Dropout Operation
      7. 7.3.7  Multi Fault Report
      8. 7.3.8  FAULT Table
      9. 7.3.9  LED Fault Summary
      10. 7.3.10 IO Pins Inner Connection
    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 Using Analog Dimming Controlled By MCU for Blind Spot Detection
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.3 Constant-Current Output and Setting (IN)

The TPS92629-Q1 device is a high-side current driver for driving LEDs. The device controls each output current through regulating the voltage drop on an external high-side current-sense resistor, R(SNS). An integrated error amplifier drives an internal power transistor to maintain the voltage drop on the current-sense resistor R(SNS) to V(CS_REG) and therefore regulates the current output to target value. When the output current is in regulation, the current value for each channel can be calculated by using Equation 1.

Equation 1. GUID-20230505-SS0I-6JDK-R2J0-D1NHWPWRS1H1-low.svg

where

  • The duty cycle on ADIM pin controls the V(CS_REG) proportionally when the ADIM pin frequency is higher than 10kHz
  • V(CS_REG) = 463.5 mV for the typical value when the ADIM pin duty cycle is 100%

When the supply voltage drops below total LED string forward voltage plus required headroom voltage, the sum of V(DROPOUT) and V(CS_REG), the TPS92629-Q1 is not able to deliver enough current output as set by the value of R(SNS), and the voltage across the current-sense resistor R(SNS) is less than V(CS_REG).