TPS65381-Q1 (ACTIVE)

Multi-Rail Automotive Power Supply for Microcontrollers in Safety-Critical Applications


The TPS65381-Q1 device is a multi-rail power supply designed to supply microcontrollers in safety applications, such as those found in automotive applications. The device supports Texas Instruments’ TMS570LS series 16- bit or 32-bit RISC flash MCU and other microcontrollers with dual-core lockstep (LS) or loosely-coupled architectures (LC).

The TPS65381-Q1 device integrates multiple supply rails to power the MCU, CAN, or FlexRay, and an external sensor. An asynchronous-buck switch-mode power-supply converter with an internal FET converts the input battery voltage to a 6-V pre-regulator output. This 6-V pre-regulator supplies the other regulators. Furthermore, the device supports wake-up from IGNITION or wake-up from the CAN transceiver.

A fixed 5-V linear regulator with an internal FET is integrated to be used as, for example, a CAN supply. A second linear regulator, also with an internal FET, regulates the 6 V to a selectable 5-V or 3.3-V MCU I/O voltage.

The TPS65381-Q1 device comprises a linear regulator controller with an external FET and resistor divider that regulates the 6 V to an externally adjustable core voltage of between 0.8 V and 3.3 V.

The device comprises a sensor supply with short-to-ground and short-to-battery protection. Therefore this supply can power a sensor outside the electronic-control unit (ECU).

The device has an integrated charge pump to provide overdrive voltage for the internal regulators. Reverse-battery protection is obtained 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.

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

The TPS65381-Q1 safety functions feature a question-answer watchdog, MCU error-signal monitor, clock monitoring on internal oscillators, self-check on the clock monitor, CRC on non-volatile memory, a diagnostic output pin allowing the MCU to observe the internal analog and digital signals of the device, a reset circuit for the MCU, and an enable output to disable the safing-path or external power-stages on any detected system-failure. A built-in self-test (BIST) monitors the device functionality at start-up. A dedicated DIAGNOSTIC state allows the MCU to check TPS65381-Q1 safety functions.

The TPS65381-Q1 device is offered in an HTSSOP-32 PowerPAD package.


  • 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
  • Multi-Rail Power Supply Supporting Among Others:
    • Texas Instruments TMS570LS Series 16-Bit or
      32-Bit RISC Flash Microcontroller
  • 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 Voltage Functional)
    • 6-V Asynchronous Switch-Mode Pre-Regulator With Internal FET,
      1.3-A Current-Limit, and Temperature Protection
    • 5-V (CAN) Supply Voltage, Linear Regulator With Internal FET,
      350-mA Current-Limit, and Temperature Protection
    • 3.3-V or 5-V MCU I/O Voltage, Linear Regulator With Internal FET,
      350-mA Current-Limit, and Temperature Protection
    • 0.8-V to 3.3-V Adjustable MCU Core Voltage, Linear Regulator
      Controller With External FET
    • Sensor Supply: Linear Tracking Regulator With Tracking Input,
      100-mA Current-Limit, Temperature Protection, and Protection
      Against Short to Battery and Short to Ground
    • Charge Pump: Typ. 12 V Above Battery Voltage
  • Power Supply and System Monitoring:
    • Independent Under- and Overvoltage Monitoring on All
      Regulator Outputs, Battery Voltage, and Internal Supplies
    • Independent Bandgap Reference for Voltage Monitoring
    • Independent Voltage References for Regulator References and
      Voltage Monitoring. Voltage-Monitoring Circuitry With
      Separate Battery Voltage Input Pin
    • Self-Check on all Voltage Monitoring (During Power-Up and
      After Power-Up Initiated by External MCU)
    • Junction Temperature Sensing With Shutdown Thresholds
  • Microcontroller Interface
    • Open-Close Window or Question-Answer Watchdog Function
    • MCU Error-Signal Monitor (Supports TI TMS570 MCU Mode or
      Other MCUs with PWM-Like Signaling)
    • DIAGNOSTIC State for Performing Device Self-Tests,
      Diagnostics, and External Interconnect Checks
    • Safe-State for Device and System Protection on Error Event
    • Clock Monitor for Internal Oscillators
    • Self-Tests for Analog- and Digital-Critical Circuits Executed
      With Every Device Power Up or Activated by External MCU in
      DIAGNOSTIC State
    • CRC on Non-Volatile Memory, Device, and System Configuration
    • Reset circuit for MCU
    • Diagnostic Output Pin Allowing MCU to Observe Device Internal
      Analog and Digital Signals, Selectable Through Multiplexer
  • SPI Interface
    • Configuring IC Registers
    • Watchdog Question-Answering
    • Diagnostic Readout
    • Compliant With 3.3-V and 5-V Logic Levels
  • Enable-Drive Output for Disabling Safing-Path or External
    Power-Stages on Any Detected System-Failure
  • Wake-Up Through IGNITION Pin or CAN WAKUP Pin
  • Package: 32-Pin HTSSOPPowerPAD™ Package

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Parametrics Compare all products in Power Management Multi-Channel IC (PMIC) Solutions

Regulated Outputs (#)
Processor Supplier
Processor Name
Vin (Min) (V)
Vin (Max) (V)
Vout (Max) (V)
Step-Up DC/DC Controller
Step-Down DC/DC Controller
Step-Up DC/DC Converter
Step-Down DC/DC Converter
Iout (Max) (A)
Iq (Typ) (mA)
Special Features
Operating Temperature Range (C)
Approx. Price (US$)
Texas Instruments    
Comm Control
Power Good
Thermal Shutdown
-40 to 125    
2.57 | 1ku    
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