方案描述：

　　专门用于关键安全应用的先进的16位和32位MCU，已成为当前电子助力转向系统的核心组件。这些控制器可提供更强的计算能力和用以支持复杂电机控制功能的专用片内外设。集成式电源解决方案也是电子助力转向单元的重要组件。它们集成了用于CAN和LIN等各种汽车总线互连能力。MCU通常可以通过SPI接口或直接控制内置的预驱动器，对功率MOSFET进行驱动。

　　方案设计图：

方案关键器件表：

　　S12XE

　　概述

　　S12XE系列提升了S12XD系列，提高了系统完整性和功能性，包括：

　　存储器保护单元(MPU)

　　纠错码(ECC)

　　增强的EEPROM功能

　　增强的XGATE

　　频率调制闭环

　　快速模数转换器(ADC)

　　此外，S12XE系列的特性还包括：

　　使S12X产品系列的闪存容量提高到1MB，208引脚的旗舰版MC9S12XE100还增加了I/O的数量

　　既具有32位微控制器的性能，又提供16位微控制器的所有优势和高效率。

　　针对汽车多路复用、通用型汽车车身和工业控制应用进行了优化

　　特性

　　XGATE协处理器帮助建立虚拟外设，提高整体性能

　　灵活的、可编程的硬件仿真EEPROM

　　支持系统完整性，提供存储保护单元与超级用户/用户模式

　　S12X CPU @ 50Mhz总线频率

　　模数转换器(ADC)，12 位分辨率和 3μs转换时间

　　增强型捕捉定时器(ECT)

　　周期中断定时器(PIT)

　　实时中断(RTI)

　　异步周期性中断(API)

　　脉宽调制器(PWM)

　　MSCAN模块

　　串行外设接口(SPI)

　　串行通信接口(SCI)

　　后台调试模块(BDM)和调试器(xDBG)

　　片上稳压器

　　本产品包含在恩智浦产品长期供货计划中，自推出后至少保证15年供货

　　超高可靠性MCU

　　MC33742

　　The 33742 and the 33742S are SPI-controlled System Basis Chips (SBCs) combining many frequently used functions along with a CAN 2.0-compliant transceiver, used in many automotive electronic control units (ECUs). The 33742 SBC has a fully protected fixed 5.0 V low dropout internal regulator with current limiting, overtemperature pre-warning, and reset. A second 5.0 V regulator can be implemented using external pass PNP bipolar junction pass transistor driven by the SBC’s external V2 sense input and V2 output drive pins.

　　The SBC has four main operating modes: Normal, Standby, Stop, and Sleep mode. Additionally there is an internally switched high-side power supply output, four wake-up inputs pins, a programmable window watchdog, interrupt, reset, and a SPI module for communication and control. The high-speed CAN A and B transceiver is available for inter-module communication.

　　Features

　　•1.0 Mbps CAN Transceiver Bus Interface with Bus Diagnostic Capability

　　•SPI Control at Frequencies up to 4.0 Mhz

　　•5.0 V Low Dropout Voltage Regulator with Current Limiting,

　　Overtemperature Pre-Warning, and Output Monitoring and Reset

　　•A Second 5.0 V Regulator Capability using an External Series Pass Transistor

　　•Normal, Standby, Stop, and Sleep Modes of Operation with Low Sleep and Stop Mode Current

　　•A High-Side (HS) Switch Output Driver for Controlling External Circuitry.

　　•Pb-Free Packaging Designated by Suffix Code EG and EP

　　MC33981

　　The 33981 is a high-frequency, self-protected 4.0mΩ RDS(ON) high-side switch used to replace electromechanical relays, fuses, and discrete devices in power management applications.

　　The 33981 can be controlled by pulse-width modulation (PWM) with a frequency up to 60kHz. It is designed for harsh environments, and it includes self-recovery features. The 33981 is suitable for loads with high inrush current, as well as motors and all types of resistive and inductive loads.

　　The 33981 is packaged in a 12x12nonleaded power-enhanced Power QFN package with exposed tabs.

　　Features

　　•Single 4.0mΩ RDS(ON) Maximum High-Side Switch •PWM Capability up to 60kHz with Duty Cycle from 5% to 100%•Very Low Standby Current

　　•Slew Rate Control with External Capacitor

　　•Overcurrent and Overtemperature Protection, Undervoltage Shutdown and Fault Reporting

　　•Reverse Battery Protection

　　•Gate Drive Signal for External Low-Side N-Channel MOSFET with Protection Features

　　•Output Current Monitoring •

　　Temperature Feedback