原标题：TI TIC12400-Q1 12V汽车系统24路输入开关检测方案

　　TI公司的TIC12400-Q1是用在12V汽车系统的24路输入多路开关检测接口(MSDI)器件,集成了10位ADC来检测模拟开关多种位置,集成的比较器用来检测MCU的数字开关,检测阈值可编程,以支持各种开关拓扑和系统非理想性,工作温度–40℃ 到125℃,支持连续模式和轮询模式,主要用在12V汽车系统中的车体控制和网关,汽车照明,加热和冷却,电动座椅和镜子.本文介绍了TIC12400-Q1主要特性,框图和应用电路,以及评估模块TIC12400 EVM特性,框图,主板和开关板电路图,材料清单.

　　The TIC12400-Q1 is an advanced Multiple SwitchDetection Interface (MSDI) designed to detectexternal switch status in a 12-V automotive system.The TIC12400-Q1 features an integrated 10-bit ADCto monitor multi-position analog switches and acomparator to monitor digital switches independentlyof the MCU. Detection thresholds can beprogrammed for the ADC and the comparator tosupport various switch topologies and system nonidealities.

　　The device monitors 24 direct switch inputs,with 10 inputs configurable to monitor switchesconnected to either ground or battery. 6 uniquewetting current settings can be programmed for eachinput to support different application scenarios. Thedevice supports wake-up operation on all switchinputs to eliminate the need to keep the MCU activecontinuously, thus reducing power consumption of thesystem. The TIC12400-Q1 also offers integrated faultdetection, ESD protection, and diagnostic functionsfor improved system robustness. The TIC12400-Q1supports 2 modes of operations: continuous and　polling mode. In continuous mode, wetting current issupplied continuously. In polling mode, wettingcurrent is turned on periodically to sample the inputstatus based on a programmable timer, thus thesystem power consumption is significantly reduced.

　　TIC12400-Q1主要特性:

　　• Qualified for Automotive Applications

　　• AEC-Q100 Qualified With the Following Results:

　　– Device Temperature Grade 1: –40 ℃ to 125℃ Ambient Operating Temperature

　　– Device HBM ESD Classification Level H2

　　– Device CDM ESD Classification Level C4B

　　• Designed to Support 12-V Automotive Systemswith Over-voltage and Under-voltage Warning

　　• Monitors up to 24 Direct Switch Inputs with 10Inputs Configurable to Monitor Switches

　　Connected to Either Ground or Battery

　　• Switch Input Withstands up to 40 V (Load DumpCondition) and down to –24 V (Reverse PolarityCondition)

　　• 6 Configurable Wetting Current Settings:(0 mA, 1 mA, 2 mA, 5 mA, 10 mA, and 15 mA)

　　• Integrated 10-bit ADC for Multi-Position AnalogSwitch Monitoring

　　• Integrated Comparator with 4 ProgrammableThresholds for Digital Switch Monitoring

　　• Ultra-low Operating Current in Polling Mode:

　　68 μA Typical (tPOLL = 64 ms, tPOLL_ACT = 128 μs,All 24 Inputs Active, Comparator Mode, AllSwitches Open)

　　• Interfaces Directly to MCU Using 3.3 V/5 VSerial Peripheral Interface (SPI) protocol

　　• Interrupt Generation to Support Wake-UpOperation on All Inputs

　　• Integrated Battery and Temperature Sensing

　　• ±8 kV Contact Discharge ESD Protection on InputPins per ISO-10605 With Appropriate ExternalComponents

　　• 38-Pin TSSOP Package

　　TIC12400-Q1应用:

　　• Body Control Module and Gateway

　　• Automotive Lighting

　　• Heating and Cooling

　　• Power Seats

　　• Mirrors

　　图1.TIC12400-Q1框图

　　图2.TIC12400-Q1简化电路图

　　图3.TIC12400-Q1在12V汽车系统应用电路图

　　图4.TIC12400-Q1在车体控制模块的应用电路图

　　评估模块TIC12400 EVM

　　The TIC12400 is a multiple switch detection interface that is designed to detect the opening and closing ofup to 24 switch contacts. 10 out of the 24 inputs are configurable to detect switch states that are eitherbattery connected switches (BCS) or ground connected switches (GCS), which means it can either sink orsource current from the channel. The remaining 14 channels are design to support ground connectedswitches only (source current). The wetting current can be preprogrammed to six available values, whichaccommodates for different application scenarios. Communication to and from the device is done using a24-bit SPI protocol.

　　The TIC124000 and TIC12400-Q1 provide the same functionality and the TIC12400 Evaluation Module isused for both devices.

　　主板材料清单:

　　开关板材料清单:

　　详情请见:

tic12400-q1.pdf

scpu036.pdf