SNVAA92 November   2023 LM63625-Q1 , TPS37-Q1 , TPS3703-Q1 , TPS3850-Q1

 

  1.   1
  2.   Abstract
  3. 1Introduction
  4. 2Power Designs for Safety MCUs With Functional Safety Requirements
  5. 3ASIL B Power-Supply Design Example and FMEDA Analysis
    1. 3.1 Functional Safety Requirements
    2. 3.2 Proposed Power Design
    3. 3.3 FMD and Pin FMA
    4. 3.4 LM63625-Q1 and TPS37A-Q1 FMEDA Analysis at the Die Level
    5. 3.5 LM63625-Q1 and TPS37A-Q1 FMEDA Analysis at the Pin Level
      1.      11
    6. 3.6 Total FMEDA Analysis of the LM63625-Q1 and TPS37A-Q1
  6. 4Summary
  7. 5Additional Resources

Abstract

Functional safety is important in automotive applications such as advanced driver assistance systems (ADAS), battery management systems (BMS), digital cockpits, and instrument clusters. Designers often wonder how to design power supplies for safety microcontrollers (MCU) to achieve Automotive Safety Integrity Level (ASIL) B.

This article describes a TI design leveraging two TI Functional Safety-Capable devices – the LM63625-Q1 buck converter combined with the TPS37A-Q1 supervisor – to meet random hardware fault metrics for ASIL B in digital cockpit and cluster applications. This method can also be scaled to other automotive applications.

TI Functional Safety-Capable devices are not developed according to the requirements of any functional safety standard. TI provides failure-in-time (FIT) rate and failure mode distribution information to customers to aid in the calculation of random hardware fault metrics. TI recommends integrating these components into a system through the strategy of “evaluation of hardware element” (International Organization for Standardization [ISO] 26262-8:2018, clause 13).