SDAA170 September   2026 TPS61383-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Design Requirement and System Structure
    1. 2.1 Design Requirements
    2. 2.2 System Structure
      1. 2.2.1 Centralized E‑Latch System
      2. 2.2.2 Distributed E‑Latch System
  6. 3Power Train
    1. 3.1 Integrated E-Latch Power Train with TPS61383-Q1
      1. 3.1.1 Super Capacitor Charger Function Introduction
      2. 3.1.2 Boost Function Introduction
      3. 3.1.3 Super Capacitor Bleeding
    2. 3.2 Hardware Design Procedure
      1. 3.2.1 Selecting the External MOSFET
      2. 3.2.2 Inductor Selection
      3. 3.2.3 Capacitor in Super Capacitor Side
      4. 3.2.4 Boost Output Capacitor
      5. 3.2.5 Loop Compensation Design
      6. 3.2.6 Key Considerations
    3. 3.3 Software Initial Process
  7. 4Super Capacitor Energy Modeling Basis and Selection
    1. 4.1 Discharge Profile and Cut-off Voltage
    2. 4.2 Super Capacitor Discharge Energy Modeling
    3. 4.3 Calculation Example
    4. 4.4 Super Capacitor Excel Calculation Tool
  8. 5Super Capacitor Management
    1. 5.1 Voltage Monitoring with BQ76907-Q1
    2. 5.2 Cell Balancing with BQ76907-Q1
      1. 5.2.1 Balancing Strategy
      2. 5.2.2 I2C Implementation
      3. 5.2.3 Cell Balancing Current
      4. 5.2.4 Low-Side Protection Circuit Design Considerations
    3. 5.3 Super Capacitor Health Detection: Combined Solution of TPS61383-Q1 and BQ76907-Q1
  9. 6Control Unit and Communication
    1. 6.1 Control Unit Design Consideration
    2. 6.2 SBC Selection
  10. 7Execution Unit
    1. 7.1 Motor Driver Structure
    2. 7.2 Motor Driver Design Considerations
  11. 8Summary
  12. 9References

2.2.2 Distributed E‑Latch System

In a distributed architecture, each door contains its own dedicated crash‑unlock actuator, collocated with the normal e‑latch mechanism. The crash command is transmitted over the vehicle network (CAN/LIN) or through a dedicated hardwired trigger line. The TPS61383‑Q1 in each door powers both the normal‑mode motor and the local crash actuator (if electrically triggered, for example, a pyrotechnic squib or a high‑current solenoid).

Single Cell E-latch System Figure 2-4 Single Cell E-latch System

Energy Requirements:

  1. 1-2 locks for 1 door, around 60J for unlocking the locks
  2. 1-2 cells super capacitor

Advantages

  1. No mechanical linkages – fully electronic, reducing door weight and assembly time.
  2. Redundancy: failure of one door’s crash module does not affect other doors.
  3. Faster, more predictable crash response (microsecond‑level electrical trigger).
  4. Enables advanced features such as soft‑open after crash or selective unlocking.
  5. 1 cell super capacitor is enough for some cars. No need for cell balance when using one cell.

Disadvantages

  1. Higher component cost (multiple backup super capacitor pack and 4 local boost converters on each doors).
  2. Lower space constraint: Limited space on door module increases challenge on super capacitor placement.
  3. More complex safety validation per door.