JAJSJM2B July   2022  – April 2024 TPS929240-Q1

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  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 Timing Requirements
    7. 5.7 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 Device Bias and Power
        1. 6.3.1.1 Power Bias (VBAT)
        2. 6.3.1.2 5V Low-Drop-Out Linear Regulator (VLDO)
        3. 6.3.1.3 Undervoltage Lockout (UVLO) and Power-On-Reset (POR)
        4. 6.3.1.4 Power Supply (SUPPLY)
        5. 6.3.1.5 Programmable Low Supply Warning
      2. 6.3.2 Constant Current Output
        1. 6.3.2.1 Reference Current with External Resistor (REF)
        2. 6.3.2.2 64-Step Programmable High-Side Constant-Current Output
      3. 6.3.3 PWM Dimming
        1. 6.3.3.1 PWM Generator
        2. 6.3.3.2 PWM Dimming Frequency
        3. 6.3.3.3 Blank Time
        4. 6.3.3.4 Phase Shift PWM Dimming
        5. 6.3.3.5 Linear Brightness Control
        6. 6.3.3.6 Exponential Brightness Control
      4. 6.3.4 FAIL-SAFE State Operation
      5. 6.3.5 On-Chip, 8-Bit, Analog-to-Digital Converter (ADC)
        1. 6.3.5.1 Minimum On Time for ADC Measurement
        2. 6.3.5.2 ADC Auto Scan
        3. 6.3.5.3 ADC Error
      6. 6.3.6 Diagnostic and Protection in NORMAL State
        1. 6.3.6.1  VBAT Undervoltage Lockout Diagnostics in NORMAL state
        2. 6.3.6.2  Low-Supply Warning Diagnostics in NORMAL State
        3. 6.3.6.3  Supply Undervoltage Diagnostics in NORMAL State
        4. 6.3.6.4  Reference Diagnostics in NORMAL state
        5. 6.3.6.5  Pre-Thermal Warning in NORMAL state
        6. 6.3.6.6  Overtemperature Protection in NORMAL state
        7. 6.3.6.7  Overtemperature Shutdown in NORMAL state
        8. 6.3.6.8  LED Open-Circuit Diagnostics in NORMAL state
        9. 6.3.6.9  LED Short-Circuit Diagnostics in NORMAL state
        10. 6.3.6.10 Single-LED Short-Circuit Detection in NORMAL state
        11. 6.3.6.11 EEPROM CRC Error in NORMAL state
        12. 6.3.6.12 Communication Loss Diagnostic in NORMAL State
        13. 6.3.6.13 Fault Masking in NORMAL state
        14.       53
      7. 6.3.7 Diagnostic and Protection in FAIL-SAFE states
        1. 6.3.7.1  Supply Undervoltage Lockout Diagnostics in FAIL-SAFE states
        2. 6.3.7.2  Low-Supply Warning Diagnostics in FAIL-SAFE states
        3. 6.3.7.3  Supply Undervoltage Diagnostics in FAIL-SAFE State
        4. 6.3.7.4  Reference Diagnostics in FAIL-SAFE states
        5. 6.3.7.5  Pre-Thermal Warning in FAIL-SAFE state
        6. 6.3.7.6  Overtemperature Protection in FAIL-SAFE state
        7. 6.3.7.7  Overtemperature Shutdown in FAIL-SAFE state
        8. 6.3.7.8  LED Open-Circuit Diagnostics in FAIL-SAFE state
        9. 6.3.7.9  LED Short-Circuit Diagnostics in FAIL-SAFE state
        10. 6.3.7.10 Single-LED Short-Circuit Detection in FAIL-SAFE state
        11. 6.3.7.11 EEPROM CRC Error in FAIL-SAFE State
        12. 6.3.7.12 Fault Masking in FAIL-SAFE state
        13.       Diagnostics Table in FAIL-SAFE State
      8. 6.3.8 OFAF Setup In FAIL-SAFE state
      9. 6.3.9 ERR Output
    4. 6.4 Device Functional Modes
      1. 6.4.1 POR State
      2. 6.4.2 INITIALIZATION state
      3. 6.4.3 NORMAL state
      4. 6.4.4 FAIL-SAFE state
      5. 6.4.5 PROGRAM state
    5. 6.5 Programming
      1. 6.5.1 FlexWire Protocol
        1. 6.5.1.1 Protocol Overview
        2. 6.5.1.2 UART Interface Address Setting
        3. 6.5.1.3 Status Response
        4. 6.5.1.4 Synchronization Byte
        5. 6.5.1.5 Device Address Byte
        6. 6.5.1.6 Register Address Byte
        7. 6.5.1.7 Data Frame
        8. 6.5.1.8 CRC Frame
        9. 6.5.1.9 Burst Mode
      2. 6.5.2 Registers Lock
      3. 6.5.3 Register Default Data
      4. 6.5.4 EEPROM Programming
        1. 6.5.4.1 Chip Selection by Pulling REF Pin High
        2. 6.5.4.2 Chip Selection by ADDR Pins Configuration
        3. 6.5.4.3 EEPROM Register Access and Burn
        4. 6.5.4.4 EEPROM PROGRAM State Exit
    6. 6.6 Register Maps
      1. 6.6.1 BRT Registers
      2. 6.6.2 IOUT Registers
      3. 6.6.3 CONF Registers
      4. 6.6.4 CTRL Registers
      5. 6.6.5 FLAG Registers
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Smart Rear Lamp with Distributed LED Drivers
      2. 7.2.2 Design Requirements
      3. 7.2.3 Detailed Design Procedure
      4. 7.2.4 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 ドキュメントの更新通知を受け取る方法
    2. 8.2 サポート・リソース
    3. 8.3 Trademarks
    4. 8.4 静電気放電に関する注意事項
    5. 8.5 用語集
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.6.2 Low-Supply Warning Diagnostics in NORMAL State

The TPS929240-Q1 continuously monitors the SUPPLY voltage and compares the results with internal threshold V(LOWSUPTH) set by LOWSUPTH for low-supply voltage warning.

If the supply voltage is lower than threshold, the device pulls ERR pin down with one pulsed current sink for 50 µs to report the fault and set flag registers including FLAG_LOWSUP and FLAG_ERR to 1.

The fault is latched in flag registers. When the supply voltage rises above low-supply warning threshold, the master controller must write 1 to register CLRFAULT to clear FLAG_LOWSUP and FLAG_ERR. The CLRFAULT bit automatically returns to 0.

The low-supply warning is also used to disable the LED open-circuit detection and single-LED short-circuit detection. When the voltage applied on SUPPLY pin is higher than the threshold V(LOWSUPTH), the TPS929240-Q1 enables LED open-circuit and single-LED short-circuit diagnosis. When V(SUPPLY) is lower than the threshold V(LOWSUPTH), the device disables LED-open-circuit detection and single-LED short-circuit diagnosis. Because when V(SUPPLY) drops below the maximum total LED forward voltage plus required V(OUT_drop) at required current, the TPS929240-Q1 is not able to deliver sufficient current output. The device pulls the voltage of each output channel as close as possible to the V(SUPPLY). In this condition, the LED open-circuit fault or single-LED short-circuit fault can be detected and reported by mistake. Setting the low-supply warning threshold high enough can avoid the LED open-circuit and single LED short-circuit fault being detected when V(SUPPLY) drops to low. The V(LOWSUPTH) is programmable from 4 V to 35 V at 1-V interval.