SLVSGW5A November   2022  – January 2024 TPS92620-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Power Supply (SUPPLY)
        1. 6.3.1.1 Power-On Reset (POR)
        2. 6.3.1.2 Suppply Current in Fault Mode
      2. 6.3.2  Enable and Shutdow(EN)
      3. 6.3.3  Constant-Current Output and Setting (INx)
      4. 6.3.4  Thermal Sharing Resistor (OUTx and RESx)
      5. 6.3.5  PWM Control (PWMx)
      6. 6.3.6  Supply Control
      7. 6.3.7  Diagnostics
        1. 6.3.7.1 LED Short-to-GND Detection
        2. 6.3.7.2 LED Open-Circuit Detection
        3. 6.3.7.3 LED Open-Circuit Detection Enable (DIAGEN)
        4. 6.3.7.4 Overtemperature Protection
        5. 6.3.7.5 Low Dropout Operation
      8. 6.3.8  FAULT Bus Output With One-Fails-All-Fail
      9. 6.3.9  FAULT Table
      10. 6.3.10 LED Fault Summary
      11. 6.3.11 IO Pins Inner Connection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Undervoltage Lockout, V(SUPPLY) < V(POR_rising)
      2. 6.4.2 Normal Operation V(SUPPLY) ≥ 4.5V
      3. 6.4.3 Low-Voltage Dropout Operation
      4. 6.4.4 Fault Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 BCM Controlled Rear Lamp With One-Fails-All-Fail Setup
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Independent PWM Controlled Rear Lamp By MCU
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.7.1 LED Short-to-GND Detection

The TPS92620-Q1 device has LED short-to-GND detection. The LED short-to-GND detection monitors the output voltage when the output current is enabled. After a short-to-GND LED failure is detected, the device turns off the faulty channel and retries automatically, regardless of the state of the PWM input. If the retry mechanism detects the removal of the LED short-to-GND fault, the device resumes to normal operation.

The TPS92620-Q1 monitors both V(OUTx) voltage and V(RESx) voltage of each channel and compares it with the internal reference voltage to detect a short-to-GND failure. If V(OUTx) or V(RESx) voltage falls below V(SG_th_falling) longer than the deglitch time of t(SG_deg), the device asserts the short-to-GND fault and pulls low the FAULT pin. During the deglitching time period, if V(OUTx) and V(RESx) rises above V(SG_th_rising), the timer is reset.

After the TPS92620-Q1 has asserted a short-to-GND fault, the device turns off the faulty output channel and retries automatically with a small current. During retrying, the device sources a small current I(Retry) from SUPPLY to OUT and RES to pull up the LED loads continuously. After auto-retry detects output voltage rising above V(SG_th_rising), it clears the short-to-GND fault and resumes to normal operation. Figure 6-3 illustrates the timing for LED short-circuit detection, protection, retry and recovery.

GUID-20231219-SS0I-GH5G-G5ZK-VB47C4WBFMFP-low.svg Figure 6-3 LED Short-to-GND Detection and Recovery Timing Diagram

The detailed information and value of each time period in Figure 6-3 is described in TIMING section of the Electrical Characteristics.