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Application NoteNxp

Managing Failure Detections and Using Required Components for MC33903/4/5 Common Mode Choke Implementation

Application note detailing hardware protection and software management for CAN interfaces in MC33903/4/5 SBCs to meet ISO 7637-2 pulse 1 transient requirements.

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Overview

This application note provides technical recommendations for implementing NXP MC33903, MC33904, and MC33905 System Basis Chips (SBC) in automotive CAN applications. It details the use of protection elements like the NUP2105L or PESD1CAN dual Zener diodes to improve device performance against ISO 7637 pulse 1 when a common mode choke is used. The document also outlines software practices for detecting and recovering from CAN interface failures, including TxD dominant, RxD short circuits, and driver over-temperature conditions. It provides specific SPI command sequences and flow charts for managing status flags and re-enabling the CAN driver after a fault recovery.

Use Cases

  • Automotive ECU design requiring ISO 7637 pulse 1 transient protection on CAN lines.
  • Implementing software recovery routines for CAN bus failures in MC33903/4/5 based systems.
  • Selecting appropriate ESD and transient protection components for CAN networks using common mode chokes.

Topics

MC33903
MC33904
MC33905S
MC33905D
CAN Interface
ISO 7637-2
System Basis Chip
NUP2105L
PESD1CAN
Common Mode Choke
SPI Management
Failure Detection

Referenced Parts

PESD1CAN

NXP

D1: NUP2105L package SOT23 (or PESD1CAN)

MC33903

NXP

IC1: MC33903, MC33904, MC33905S, MC33905D

MC33904

NXP

IC1: MC33903, MC33904, MC33905S, MC33905D

MC33905D

NXP

IC1: MC33903, MC33904, MC33905S, MC33905D

MC33905S

NXP

IC1: MC33903, MC33904, MC33905S, MC33905D

ACT45B-510

TDK

L1: Common Mode Choke per customer requirement, i.e TDK ACT45B-510

NUP2105L

onsemi

D1: NUP2105L package SOT23 (or PESD1CAN)

ACT45B-510

TDK

ment, i.e TDK ACT45B-510

Managing Failure Detections and Using Required Components for MC33903/4/5 Common Mode Choke Implementation | Design Resources