原标题：On Semi NCV7471系统基础芯片汽车电控制解决方案

　　On Semi公司的NCV7471系统基础芯片(SBC)集成了车体的汽车电控单元(ECU)的功能,提供和监视应用微控制器和其它负载的低压电源,通过看门狗监视应用软件,以及高速CAN和LIN收发器,是ECU成为多个通信节点或用作网关单元.本文介绍了NCV7471主要特性,框图和应用框图,以及系统基础芯片(SBC)评估板主要特性,电路图,材料清单和PCB设计图.

　　NCV7471 is a System Basis Chip (SBC) integrating functions typically found in automotive Electronic Control Units (ECUs) in the body domain. NCV7471 provides and monitors the low-voltage power supplies for the application microcontroller and other loads, monitors the application software via a watchdog and includes high-speed CAN and LIN transceivers allowing the ECU to host multiple communication nodes or to act as a gateway unit. The on-chip state controller ensures safe power-up sequence and supports low-power modes with a configurable set of features including wakeup from the communication buses or by a local digital signal WU. The status of several NCV7471 internal blocks can be read by the microcontroller through the serial peripheral interface or can be used to generate an interrupt request.

　　NCV7471主要特性:

　　Control Logic

　　- Ensures safe powerup sequence and the correct reaction to different supply conditions

　　- Controls mode transitions including the power management and wakeup treatment bus

　　wakeups, local wakeups (via WU pin) and cyclic wakeups (through the onchip timer)

　　- Generates reset and interrupt requests

　　Serial Peripheral Interface

　　- Operates with 16bit frames

　　- Ensures communication with the ECUs microcontroller unit

　　- Mode settings, chip status feedback and watchdog are accessible through eight twelvebits registers

　　5 V VOUT Supply from a DC/DC Converter

　　- Can deliver up to 500 mA with accuracy of 2%

　　- Supplies typically the ECUs microcontroller

　　- Suitable for start stop systems with battery voltage as low as 2.5V

　　5 V VOUT2 Lowdrop Output Regulator

　　- Can supply external loads e.g. sensors

　　- Controlled by SPI and the state machine

　　- Protected against short to the car battery

　　A Highspeed CAN Transceiver

　　- ISO11898 compliant

　　- TxD dominant timeout protection

　　Two LIN Transceivers

　　- LIN2.1 and J2602 compliant

　　- TxD dominant timeout protection

　　Wakeup Input WU

　　- Edgesensitive highvoltage input

　　- Can be used as a wakeup source or as a logical input polled through SPI

　　Protection and Monitoring Functions

　　- Monitoring of the main supply through the V_MID point

　　- Monitoring of VOUT supply output with

　　programmable threshold

　　- VOUT2 supply diagnosis through SPI and interrupt

　　- Thermal warning and thermal shutdown protection

　　- Programmable watchdog monitoring the ECU software

Automotive Body Control Modules

　　图1. NCV7471框图

　　图2. NCV7471应用框图

　　NCV7471系统基础芯片(SBC)评估板

　　This document describes the NCV7471 EVB board for the ON Semiconductor NCV7471 System basis chip with a high−speed CAN and two LIN transceivers with boost−buck converter and low−drop voltage regulator. The functionality and major parameters can be evaluated with the NCV7471 EVB board.

　　NCV7471 is a System Basis Chip (SBC) integrating functions typically found in automotive Electronic Control Units (ECUs) in the body domain. NCV7471 provides and monitors the low−voltage power supplies for the application microcontroller and other loads, monitors the application software via a watchdog and includes high−speed CAN and LIN transceivers allowing the ECU to host multiple communication nodes or to act as a gateway unit. The on−chip state controller ensures safe power−up sequence and supports low−power modes with a configurable set of features including wakeup from the communication buses or by a local digital signal WU. The status of several NCV7471 internal blocks can be read by the microcontroller through the serial peripheral interface or can be used to generate an interrupt request.

　　NCV7471系统基础芯片(SBC)评估板主要特性:

　　• One−row Pin Header, Providing the Circuit Signals, Enables Easy Insertion of the Evaluation Board into a more Complex Application Setup

　　• Oscilloscope Test−points on All Important Signals

　　• Reverse Protection and Decoupling on the Main (Battery) Supply

　　• All the Necessary VOUT Converter External Components – Assembly Options Available

　　• Decoupling on VOUT Converter and VOUT2 Regulator Outputs

　　• Additional Pull−up Resistors on the Open−drain Digital Outputs (RSTN, INTN, UVN_VOUT)

　　• Filtering Circuit on the Switch−monitoring WAKE Input

　　• On−board Local Wakeup Switch

　　• CAN/LIN−bus Terminations

　　• Good Thermal Connection of the Circuit’s Exposed Pad to the Bottom Ground Plane

　　• Basic Standalone Functionality using Software Development Mode

　　图3. NCV7471系统基础芯片(SBC)评估板外形图

　　NCV7471系统基础芯片(SBC)评估板材料清单(BOM):