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

1 Introduction

Safety MCUs are widely used in safety-critical automotive systems such as digital cockpits and instrument clusters. The MCU collects safety-relevant information from various electronic control units and sensors through a Controller Area Network (CAN). The device then executes the corresponding signal processing and fault detection to achieve the system functional safety requirements. Keeping the power supply within the recommended operating range of the safety MCU is essential to prevent the MCU from running into an unsafe state.

There are four classifications of ASILs in the ISO 26262 standard based on the inherent safety risk: ASIL A, ASIL B, ASIL C, and ASIL D, with ASIL D being the most stringent requirement. The target for digital cockpit and cluster applications is typically ASIL B.