SLVSDJ1A July 2016  – May 2017 TPS65381A-Q1


  1. Device Overview
    1. 1.1Features
    2. 1.2Applications
    3. 1.3Description
    4. 1.4Typical Application Diagram
  2. Revision History
  3. Pin Configuration and Functions
  4. Specifications
    1. 4.1Absolute Maximum Ratings
    2. 4.2ESD Ratings
    3. 4.3Recommended Operating Conditions
    4. 4.4Thermal Information
    5. 4.5Electrical Characteristics
    6. 4.6Timing Requirements
    7. 4.7Switching Characteristics
    8. 4.8Typical Characteristics
  5. Detailed Description
    1. 5.1Overview
    2. 5.2Functional Block Diagram
    3. 5.3Feature Description
      1. 5.3.1VDD6 Buck Switch-Mode Power Supply
      2. 5.3.2VDD5 Linear Regulator
      3. 5.3.3VDD3/5 Linear Regulator
      4. 5.3.4VDD1 Linear Regulator
      5. 5.3.5VSOUT1 Linear Regulator
      6. 5.3.6Charge Pump
      7. 5.3.7Wake-Up
      8. 5.3.8Reset Extension
    4. 5.4Device Functional Modes
      1. 5.4.1 Power-Up and Power-Down Behavior
      2. 5.4.2 Safety Functions and Diagnostics Overview
      3. 5.4.3 Voltage Monitor (VMON)
      4. 5.4.4 TPS65381A-Q1 Internal Error Signals
      5. 5.4.5 Loss-of-Clock Monitor (LCMON)
      6. 5.4.6 Analog Built-In Self-Test (ABIST)
      7. 5.4.7 Logic Built-In Self-Test (LBIST)
      8. 5.4.8 Junction Temperature Monitoring and Current Limiting
      9. 5.4.9  Diagnostic MUX and Diagnostic Output Pin (DIAG_OUT)
        1. MUX (AMUX)
        2. MUX (DMUX)
        3. MUX Output State (by MUX_OUT bit)
        4. Interconnect Check
      10. 5.4.10Watchdog Timer (WD)
      11. 5.4.11Watchdog Fail Counter, Status, and Fail Event
      12. 5.4.12Watchdog Sequence
      13. 5.4.13MCU to Watchdog Synchronization
      14. 5.4.14Trigger Mode (Default Mode)
      15. 5.4.15Q&A Mode
        1. Q&A Related Definitions
        2. Sequence in Q&A Mode
        3. (Token) Generation
        4. Comparison and Reference Answer
          1. of the 2-bit Watchdog Answer Counter
        5. Q&A Mode Sequence Events and WD_STATUS Register Updates
      16. 5.4.16MCU Error Signal Monitor (MCU ESM)
        1. Mode
        2. Mode
      17. 5.4.17Device Configuration Register Protection
      18. 5.4.18Enable and Reset Driver Circuit
      19. 5.4.19Device Operating States
      20. 5.4.20STANDBY State
      21. 5.4.21RESET State
      22. 5.4.22DIAGNOSTIC State
      23. 5.4.23ACTIVE State
      24. 5.4.24SAFE State
      25. 5.4.25State Transition Priorities
      26. 5.4.26Power on Reset (NPOR)
    5. 5.5Register Maps
      1. 5.5.1Serial Peripheral Interface (SPI)
        1. Command Transfer Phase
        2. Data-Transfer Phase
        3. Status Flag Byte Response
        4. SPI Data Response
        5. Frame Overview
      2. 5.5.2SPI Register Write Access Lock (SW_LOCK command)
      3. 5.5.3SPI Registers (SPI Mapped Response)
        1. Revision and ID
          1. Register
          2. Register
        2. Status
          1. Register
        3. Configuration
          1. Register
          2. Register
      4. 5.5.4Device Safety Status and Control Registers
        1. VMON_STAT_1 Register
        2. VMON_STAT_2 Register
        3. SAFETY_STAT_1 Register
        4. SAFETY_STAT_2 Register
        5. SAFETY_STAT_3 Register
        6. SAFETY_STAT_4 Register
        7. SAFETY_STAT_5 Register
        8. SAFETY_ERR_CFG Register
        9. SAFETY_BIST_CTRL Register
        10. Register
        11. Register
        12. Register
        13. Register
        14. Register
        15. Register
        16. Register
          1. Register
          2. Register
      5. 5.5.5Watchdog Timer
        1. Register
        2. Register
        3. Register
        4. Register
        5. Register
        6. Register
      6. 5.5.6Sensor Supply
        1. Register
  6. Application and Implementation
    1. 6.1Application Information
    2. 6.2Typical Application
      1. 6.2.1Design Requirements
      2. 6.2.2Detailed Design Procedure
        1. Preregulator
        2. Linear Controller
        3. Tracking Linear Regulator, Configured to Track VDD5
        4. Use for VSOUT1 Tracking Linear Regulator, Configured for 6-V Output Tracking VDD3/5 In 3.3-V Mode
        5. Use for VSOUT1 Tracking Linear Regulator, Configured for 9-V Output Tracking to 5-V Input from VDD5
        6. Use for VSOUT1 Tracking Linear Regulator, Configured in Non-tracking Mode Providing a 4.5-V Output
      3. 6.2.3Application Curves
    3. 6.3System Examples
  7. Power Supply Recommendations
  8. Layout
    1. 8.1Layout Guidelines
      1. 8.1.1VDD6 Buck Preregulator
      2. 8.1.2VDD1 Linear Regulator Controller
      3. 8.1.3VDD5 and VDD3/5 Linear Regulators
      4. 8.1.4VSOUT1 Tracking Linear Regulator
      5. 8.1.5Charge Pump
      6. 8.1.6Other Considerations
    2. 8.2Layout Example
    3. 8.3Power Dissipation and Thermal Considerations
  9. Device and Documentation Support
    1. 9.1Documentation Support
      1. 9.1.1Related Documentation
    2. 9.2Receiving Notification of Documentation Updates
    3. 9.3Community Resources
    4. 9.4Trademarks
    5. 9.5Electrostatic Discharge Caution
    6. 9.6Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Device Overview


  • Qualified for Automotive Applications
  • AEC-Q100 Qualified With the Following Results:
    • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature
    • Device HBM ESD Classification Level H2
    • Device CDM ESD Classification Level C3B
  • Multirail Power Supply Supporting Among Others
    • TI Hercules™ TMS570, C2000™, and Various Functional-Safety Architecture Microcontrollers
  • Supply Rails
    • Input voltage range:
      • 5.8 V to 36 V (CAN, I/O, MCU Core, and Sensor-Supply Regulators Functional)
      • 4.5 V to 5.8 V (3.3 V I/O and MCU Core Regulators Functional)
    • 6-V Asynchronous Switch Mode Preregulator With Internal FET, 1.3-A Output Current
    • 5-V (CAN) Supply Voltage, Linear Regulator With Internal FET, 300-mA Output Current
    • 3.3-V or 5-V (MCU I/O) Voltage, Linear Regulator With Internal FET, 300-mA Output Current
    • 0.8-V to 3.3-V Adjustable (MCU Core Voltage), Linear Regulator Controller With External FET
    • 3.3-V to 9.5-V Adjustable Sensor Supply: Linear Tracking Regulator With Internal FET, 100-mA Output Current, and Protection Against Short-to-Supply and Short-to-Ground
    • Charge Pump: Typically 12 V Above Battery Voltage
  • Power Supply and System Monitoring
    • Independent Undervoltage and Overvoltage Monitoring on All Regulator Outputs, Battery Voltage, and Internal Supplies
    • Independent Voltage References for Regulator References and Voltage Monitoring. Voltage-Monitoring Circuitry With Independent Bandgap Reference and Separate Supply Input Pin
    • Self-Check on all Voltage Monitoring (Automatic During Power-Up and After Power-Up Initiated by External MCU)
    • All Supplies With Internal FETs Protected With Current-Limit and Overtemperature Shutdown
  • Microcontroller (MCU) Interface
    • Watchdog: Trigger Mode (OPEN/CLOSE Window) or Question and Answer Mode
    • MCU Error-Signal Monitor For Lock-Step Dual-Core MCUs Including Hercules™ TMS570, C2000™, and Various Functional-Safety Architecture MCUs Using Pulse-Width Modulation (PWM) Error Output
    • DIAGNOSTIC State for Performing Device Self-Tests, Diagnostics, and External Interconnect Checks
    • SAFE State for Device and System Protection on Error Event Detection
    • Clock Monitor for Internal Oscillator
    • Self-Tests for Analog- and Digital-Critical Circuits Executed With Every Device Power Up or Activated by MCU in DIAGNOSTIC State
    • CRC on Nonvolatile Memory, Device and Configuration Registers
    • Reset Circuit and Output Pin for MCU
    • Diagnostic Output Pin Allowing MCU to Observe Through a Multiplexer Internal Analog and Digital Signals of the Device
  • Serial Peripheral Interface (SPI)
    • Configuration Registers
    • Watchdog Question and Answers
    • Diagnostic Status Readout
    • Compliant With 3.3-V and 5-V Logic Levels
  • Enable Drive Output for Disabling Safing-Path or External Power-Stages on Detected System-Failure
  • Wakeup Through IGNITION Pin or CAN WAKEUP Pin
  • Package: 32-Pin HTSSOP PowerPAD™ IC Package


  • Safety Automotive Applications
    • Power Steering: Electrical Power Steering (EPS) and Electro Hydraulic Power Steering (EHPS)
    • Braking: Anti-Lock Brake System (ABS), Electronic Stability Control (ESC), and Electric Parking Brake
    • Advanced Driver Assistance Systems (ADAS)
    • Suspension
  • Industrial Safety Applications
    • Safety Programmable-Logic Controllers (PLCs)
    • Safety I/O Control Modules
    • Test and Measurement
    • Railway and Subway Signal Control and Safety Modules
    • Elevator and Escalator Safety Control
    • Wind Turbine Control


The TPS65381A-Q1 device is a multirail power supply designed to supply microcontrollers (MCUs) in safety-relevant applications, such as those found in automotive and industrial markets. The device supports Texas Instruments’ Hercules™ TMS570 MCU and C2000™ MCU families, and various other MCUs with dual-core lockstep (LS) or loosely-coupled architectures (LC).

The TPS65381A-Q1 device integrates multiple supply rails to power the MCU, controller area network (CAN), or FlexRay, and an external sensor. An asynchronous-buck switch-mode power-supply converter with an internal FET converts the input supply (battery) voltage to a 6-V preregulator output. This 6-V preregulator supplies the other regulators. The device supports wakeup from IGNITION or wakeup from the CAN transceiver.

The integrated, fixed 5-V linear regulator with internal FET can be used for a CAN or FlexRay transceiver supply for example. A second linear regulator, also with an internal FET, regulates to a selectable 5-V or 3.3-V output which, for example, can be use for the MCU I/O voltage.

The TPS65381A-Q1 device includes an adjustable linear-regulator controller, requiring an external FET and resistor divider, that regulates to an adjustable voltage of between 0.8 V and 3.3 V which may be used for the MCU core supply.

The integrated sensor supply can be run in tracking mode or adjustable output mode and includes short-to-ground and short-to-battery protection. Therefore, this regulator can power a sensor outside the module or electronic control unit (ECU).

The integrated charge pump provides overdrive voltage for the internal regulators. The charge pump can also be used in a reverse-battery protection circuit by using the charge-pump output to control an external NMOS transistor. This solution allows for a lower minimum-battery-voltage operation compared to a traditional reverse-battery blocking diode when the device must be operational at the lowest possible supply voltages.

The device monitors undervoltage and overvoltage on all regulator outputs, battery voltage, and internal supply rails. A second bandgap reference, independent from the main bandgap reference, is used for the undervoltage and overvoltage monitoring, to avoid any drifts in the main bandgap reference from being undetected. In addition, regulator current-limits and temperature protections are implemented.

The TPS65381A-Q1 device has monitoring and protection functions, which include the following: watchdog with trigger and question and answer modes, MCU error-signal monitor, clock monitoring on internal oscillators, self-check on the clock monitor, cyclic redundancy check (CRC) on nonvolatile memory, a diagnostic output pin allowing the MCU to observe internal analog and digital signals of the device, a reset circuit and output pin for the MCU, and an enable drive output to disable the safing-path or external-power stages on detected faults. A built-in self-test (BIST) monitors the device functionality automatically at power-up. A dedicated DIAGNOSTIC state allows the MCU to check TPS65381A-Q1 monitoring and protection functions.

The TPS65381A-Q1 device is offered in a 32-pin HTSSOP PowerPAD package.

Device Information(1)

TPS65381A-Q1HTSSOP (32)11.00 mm × 6.20 mm
For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application Diagram

TPS65381A-Q1 Typ_App_Dia_1_lvsbc4.gif Figure 1-1 Typical Application Diagram