原标题：freescale的sensor方案2

　　Keywords： lin bus , periodic wake-up, MM912_637FS

　　摘要：本评估模块支持MM912J637，评估系统基于飞思卡尔S12单片机技术，同时这是一个完全实现了LIN电池监控装置。

　　基本特性：

　　The MM912_637 enables precision measurement of key battery parameters in automotive and other applications. The device integrates an HCS12 microcontroller and a SMARTMOS analog control IC into a single package solution. The analog die combines system basis and application specific functions, including a Local Interconnect Network (LIN) transceiver, and a two-channel 16-bit sigma delta analog to digital converter (ADC) for simultaneous measurement of battery voltage and current. An integrated temperature sensor combined with battery mounting allows measurement of battery temperature. Control of the analog die is through a new high performance internal Die-to-Die interface (D2D), which seamlessly integrates the analog IC registers into the MCU register map, to provide faster access than SPI-based systems. The MM912_637 also includes an internal oscillator, 96 k or 128 k Bytes of Flash memory, and 6.0 k Bytes of RAM. An optional external temperature sensor is also supported.

　　方案描述：

　　Freescale Semiconductor’s KIT912J637EVME is a system solution that gives the user the capability to easily

　　evaluate most of the features provided by the MM912J637 - Xtrinsic Battery Sensor. The 912J637 features two die in a single package. The 16-bit core and the analog die are connected via the die to die interface that provides direct address access to the registers on the analog die. The analog die contains three 16-bit sigma delta converters and enables simultaneous sampling of battery voltage and current, timer module, SCI module, LIN physical interface, and other general registers. All external signals are accessible via header connectors, and most of the signals can also be checked via test points. The evaluation module board also includes the TBDML programming/debugging interface, so no external interface is needed. The board is powered from two 4.0 mm banana connectors. For quick familiarization with the device, a CodeWarrior Template is provided together with the EVB.

　　3.1 MM912J637 Features

　　• Battery voltage measurement

　　• Battery current measurement in up to eight ranges

　　• On-chip temperature measurement

　　• Normal and two low-power modes

　　• Current threshold detection and current averaging in standby => wake-up from low-power mode

　　• Triggered wake-up from LIN and periodic wake-up

　　• Signal low pass filtering (current, voltage)

　　• PGA (programmable low-noise gain amplifier) with automatic gain control feature

　　• Accurate internal oscillator (an external quartz oscillator may be used for extended accuracy)

　　• Communication via a LIN 2.1, LIN 2.0 bus interface

　　• S12 microcontroller with 128 kByte flash, 6.0 kByte RAM, 4.0 kByte data flash

　　• Background debug module

　　• External temperature sensor option (TSUP, VTEMP)

　　• Optional 2nd external voltage sense input (VOPT)

　　• 4 x 5.0 V GPIO including one wake-up capable high voltage input (PTB3/L0)

　　• 8 x MCU general purpose I/O including SPI functionality

　　• Industry standard EMC compliance

　　参考原理图：

　　原理图1

　　原理图2