ZHCSMX7A August   2021  – December 2021 TPS92519-Q1

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  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  Buck Converter Switching Operation
      2. 7.3.2  Switching Frequency and Adaptive On-Time Control
      3. 7.3.3  Minimum On-Time, Off-Time, and Inductor Ripple
      4. 7.3.4  Enable
      5. 7.3.5  LED Current Regulation and Error Amplifier
      6. 7.3.6  Start-up Sequence
      7. 7.3.7  Analog Dimming and Forced Continuous Conduction Mode
      8. 7.3.8  External PWM Dimming and Input Undervoltage Lockout (UVLO)
      9. 7.3.9  Shunt FET Dimming or Matrix Beam Application
      10. 7.3.10 Bias Supply
      11. 7.3.11 Bootstrap Supply
      12. 7.3.12 Faults and Diagnostics
      13. 7.3.13 Output Short Circuit Fault
      14. 7.3.14 Output Open Circuit Fault
      15. 7.3.15 Parallel Operation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power On Reset (POR)
      2. 7.4.2 Run Mode
      3. 7.4.3 Sleep Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  Duty Cycle Consideration
      2. 8.1.2  Switching Frequency Selection
      3. 8.1.3  LED Current Set Point
      4. 8.1.4  Inductor Selection
      5. 8.1.5  Output Capacitor Selection
      6. 8.1.6  Input Capacitor Selection
      7. 8.1.7  Bootstrap Capacitor Selection
      8. 8.1.8  Compensation Capacitor Selection
      9. 8.1.9  Input Undervoltage Protection
      10. 8.1.10 CSN Protection Diode
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Calculating Duty Cycle
        2. 8.2.2.2 Calculating Minimum On-Time and Off-Time
        3. 8.2.2.3 Minimum Switching Frequency
        4. 8.2.2.4 LED Current Set Point
        5. 8.2.2.5 Inductor Selection
        6. 8.2.2.6 Output Capacitor Selection
        7. 8.2.2.7 Bootstrap Capacitor Selection
        8. 8.2.2.8 Compensation Capacitor Selection
        9. 8.2.2.9 PWM Dimming and Input Voltage Protection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Compact Layout for EMI Reduction
        1. 10.1.1.1 Ground Plane
    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 支持资源
    4. 11.4 Trademarks
    5. 11.5 术语表
  12. 12Mechanical, Packaging, and Orderable Information

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7.3.12 Faults and Diagnostics

Table 7-1 summarizes the device behavior under fault conditions.

Table 7-1 Fault Description
FAULTDETECTIONDESCRIPTION
Thermal protectionTJ > 175°CEach channel is protected by an individual thermal sensor located close to the switching MOSFETs. The thermal protection is activated in the event the maximum MOSFET temperature exceeds the typical value of 175°C. The corresponding channel is forced into shutdown mode. This feature is designed to prevent overheating and damage to the internal switching MOSFETs.
V5D undervoltage lockoutV5D(RISE) < 4.1 VThe device enters the Undervoltage Lockout (UVLO). The switching operation is disabled, the COMP capacitor is discharged.
V5D(FALL) > 4 V
V5A undervoltage lockoutV5A(RISE) < 4.1 VIn sleep mode, the internal V5A node is disconnected to reduce the current consumption. The switching operation is disabled and the COMP capacitor is discharged.
V5A(FALL) > 4 V
VINx dropout protectionVUDIMx < 2.35 VThe device disables error amplifier and disconnects the compensation network for the corresponding channel. Error amplifier is enabled and compensation network is internally connected when the input voltage rises above the dropout rising threshold, VINx(DO,RISE).
VINx undervoltage lockout VUDIMx < 1.02 V The device disables switching operation for the corresponding channel. Switching is enabled when the input voltage rises above the turn-on threshold, VINx(UVLO,RISE).
BSTx undervoltage lockoutVBSTx(RISE) > 3.14 VThe device turns off the high-side MOSFET and turns on the low-side MOSFET for the corresponding channel. Normal switching operation is resumed after the bootstrap voltage exceeds 3.14 V.
VBSTx(FALL) < 2.95 V
COMPx overvoltageVCOMPx > 3.2 VThe FLTx flag is set low to indicate that the COMP voltage exceeded the normal operating range. This condition indicates output open circuit fault.
Short CHx outputVCSNx < 2.45 VThe FLTx flag is set low to indicate an output short circuit condition based on sensed CSNx voltage.
High-side switch current limitIHS > 3.5 AThe device turns off the high-side MOSFET and discharges the COMP capacitor when the drain current exceeds 3.5-A typical. The low-side switch is turned on to discharge the inductor and output capacitor. The device attempts to restart after delay of 3.6 ms
Low-side switch current limitILS > 2.5 AThe device turns off both high-side and low-side MOSFETs and discharges the COMP capacitor when the drain current exceeds 2.5 A typical. The device attempts to restart after delay of 3.6 ms.

The TPS92519-Q1 triggers an auto-restart on detection of the thermal shutdown, high-side, or low-side current limit faults. In the case of thermal shutdown fault, the restart is initiated after the MOSFET temperature decreases by the fixed hysteresis of 10°C. A soft-start sequence is initiated and switching operation is enabled. For a high-side or low-side current limit fault, a fixed 3.6-ms timer is initiated on detection of the fault. A restart is initiated by the expiration of the fault timer and switching operation is enabled.

The output open circuit and short circuit faults force the FLTx pin low when biased through an external resistor and connected to a 5-V supply. The FLTx output can be used in conjunction with a microcontroller or system basis chip (SBC) as an interrupt and can be used to aid in fault diagnostics.

Table 7-2 Faults and Diagnostic Summary
LIST DESCRIPTION FAULT OR DIAGNOSTIC ENABLE FAULT TIMER FLT INDICATION
Thermal protection Fault No No
VINx(DO) VIN supply dropout protection Diagnostics No No
VINx(UVLO) VIN supply undervoltage lockout Fault No No
CHxBSTUV BST supply undervoltage lockout Fault No No
CHxCOMPOV COMP overvoltage Diagnostics No Yes
CHxSHORT Short circuit detected Diagnostics No Yes
CHxHSILIM High-side current limit Fault Yes No
CHxLSILIM Low-side current limit Fault Yes No
V5AUV V5A undervoltage Diagnostics No No