SLVA528D September   2012  – August 2021 TPS65381-Q1 , TPS65381A-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2Product Overview
    1. 2.1 Safety Functions and Diagnostics Overview
    2. 2.2 Target Applications
    3. 2.3 Product Safety Constraints
  4. 3Development Process for Management of Systematic Faults
    1. 3.1 TI New-Product Development Process
  5. 4TPS65381x-Q1 Product Architecture for Management of Random Faults
    1. 4.1 Device Operating States
    2.     Device Operating States (continued)
    3. 4.2 NRES (MCU Reset) Driver and ENDRV (SAFING Path Enable) Driver
  6. 5TPS65381x-Q1 Architecture Safety Mechanisms and Assumptions of Use
    1. 5.1 Power Supply
    2. 5.2 Regulated Supplies
      1. 5.2.1 VDD6 Buck Switch-Mode Supply
      2. 5.2.2 VDD5 Linear Supply
      3. 5.2.3 VDD3/5 Linear Supply
      4. 5.2.4 VDD1 Linear Supply
      5. 5.2.5 VSOUT1 Linear Supply
      6. 5.2.6 Charge Pump
    3. 5.3 Diagnostic, Monitoring, and Protection Functions
      1. 5.3.1 External MCU Fault Detection and Management
        1. 5.3.1.1 External MCU Error Signal Monitor (MCU ESM)
        2. 5.3.1.2 Watchdog Timer
      2. 5.3.2 Voltage Monitor (VMON)
      3. 5.3.3 Loss-of-Clock Monitor (LCMON)
      4. 5.3.4 Junction Temperature Monitoring and Current Limiting
      5. 5.3.5 Analog and Digital MUX (AMUX and DMUX) and Diagnostic Output Pin (DIAG_OUT)
      6. 5.3.6 Analog Built-In Self-Test (ABIST)
      7. 5.3.7 Logic Built-In Self-Test (LBIST)
      8. 5.3.8 Device Configuration Register Protection
  7. 6Application Diagrams
    1. 6.1 TPS65381x-Q1 With TMS570
    2. 6.2 TPS65381x-Q1 With C2000
    3. 6.3 TPS65381x-Q1 With TMS470
  8. 7TPS65381x-Q1 as Safety Element out of Context (SEooC)
    1. 7.1 TPS65381x-Q1 Used in an EV/HEV Inverter System
    2. 7.2 SPI Note
  9. 8Revision History

2 Product Overview

The TPS65381x-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™ families, and various other MCUs with dual-core lockstep (LS) or loosely-coupled architectures (LC).

The TPS65381x-Q1 integrates multiple supply rails to power the MCU, transceiver (CAN or other), and an external sensor. An asynchronous buck switch-mode power-supply converter with internal FET converts the input supply (battery) to a 6-V preregulator output. This 6 V supplies the other regulators.

The integrated 5-V linear regulator with internal FET is typically used to supply a transceiver or other peripheral. A second integrated linear regulator, also with internal FET, regulates to a selectable 5-V or 3.3-V MCU I/O voltage.

The TPS65381x-Q1 includes the VDD1 voltage-regulator controller, typically used to supply the MCU core rail. This linear regulator controller uses an external FET and resistor divider (for adjustment). It regulates the 6 V to an adjustable voltage of between 0.8 V and 3.3 V for the core.

The device includes a sensor supply, VSOUT1.

The device has an integrated charge pump to provide an overdrive voltage for the internal regulators. One option for reverse-battery protection uses 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 because there is less voltage drop across the transistor.

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, monitors for undervoltage and overvoltage, to avoid any drifts in the main band-gap reference being undetected. In addition, the device implements regulator current limits and temperature protections.

The TPS65381x-Q1 functional safety architecture features a watchdog configurable for question and answer (Q&A) mode or trigger mode, MCU error-signal monitor (ESM), diagnostic check for the MCU ESM, clock monitoring on internal oscillators, self-check on clock monitor, CRC on internal nonvolatile memory (EEPROM), CRC for configuration registers, diagnostic multiplex output to route internal analog (AMUX) and digital (DMUX) signals out through the DIAG_OUT pin, and a reset circuit for the MCU. A built-in self-test (BIST) allows for monitoring the device functionality at power up.

GUID-CC311C02-638D-4097-949C-7E247F307374-low.gifFigure 2-1 TPS65381x-Q1 Architecture Overview