LTC2943具温度电压和电流测量功能的多节电池电量测量芯片解析.docx

1、LTC2943 具温度电压和电流测量功能的多节电池电量测量芯片解析LTC2943 - 具温度、电压和电流测量功能的多节电池电量测量芯片特点 可测量累积的电池充电和放电电量 3.6V 至 20V 工作范围可适合多种电池应用 14 位 ADC 负责测量电池电压、电流和温度 1% 电压、电流和充电准确度 50mV 检测电压范围 高压侧检测 适合任何电池化学组成和容量的通用测量 I2C / SMBus 接口 可配置警报输出 / 充电完成输入 静态电流小于 120A 小外形 8 引脚 3mm x 3mm DFN 封装典型应用描述LTC2943可测量便携式产品应用中的电池充电状态、电池电压、电池电流及其自

2、身温度。其具有宽输入电压范围，因而可与高达20V的多节电池配合使用。一个精准的库仑计量器负责对流经位于电池正端子和负载或充电器之间的一个检测电阻器电流进行积分运算。电池电压、电流和温度利用一个内部14位无延迟增量累加(No Latency TM) ADC来测量。测量结果被存储于可通过内置I2C / SMBus接口进行存取的内部寄存器中。LTC2943具有针对所有4种测量物理量的可编程高门限和低门限。如果超过了某个编程门限，则该器件将采用SMBus警报协议或通过在内部状态寄存器中设定一个标记来传送警报信号。LTC2943仅需采用单个低阻值检测电阻器以设定测量电流范围。应用 电动工具 电动自行车

3、便携式医疗设备 视频摄像机程序：#include #include #include Linduino.h#include LT_I2C.h#include UserInterface.h#include QuikEval_EEPROM.h#include LTC2943.h#include / Function Declarationvoid print_title(); / Print the title blockvoid print_prompt(); / Print the Promptvoid store_alert_settings(); / Store the alert se

4、ttings to the EEPROMint8_t restore_alert_settings(); / Read the alert settings from EEPROM#define AUTOMATIC_MODE_DISPLAY_DELAY 1000 /! The delay between readings in automatic mode#define SCAN_MODE_DISPLAY_DELAY 10000 /! The delay between readings in scan modeconst float resistor = .100; /! resistor

5、value on demo board/ Error stringconst char ack_error = Error: No Acknowledge. Check I2C Address.; /! Error message/ Global variablesstatic int8_t demo_board_connected; /! Set to 1 if the board is connectedstatic uint8_t alert_code = 0; /! Value stored or read from ALERT register. Shared between loo

6、p() and restore_alert_settings()/! Initialize Linduinovoid setup() char demo_name = DC1812; /! Demo Board Name stored in QuikEval EEPROM quikeval_I2C_init(); /! Configure the EEPROM I2C port for 100kHz quikeval_I2C_connect(); /! Connects to main I2C port Serial.begin(115200); /! Initialize the seria

7、l port to the PC print_title(); demo_board_connected = discover_demo_board(demo_name); if (demo_board_connected) print_prompt(); else demo_board_connected = true; Serial.println(Did not read ID String, attempting to proceed anyway.nPlease ensure I2C lines of Linduino are connected to the LTC device)

8、; /! Repeats Linduino loopvoid loop() int8_t ack = 0; /! I2C acknowledge indicator static uint8_t user_command; /! The user input command static uint8_t mAh_or_Coulombs = 0; static uint8_t celcius_or_kelvin = 0; static uint16_t prescalar_mode = LTC2943_PRESCALAR_M_4096; static uint16_t prescalarValu

9、e = 4096; static uint16_t alcc_mode = LTC2943_ALERT_MODE; if (demo_board_connected) /! Do nothing if the demo board is not connected if (Serial.available() /! Do nothing if serial is not available user_command = read_int(); /! Read user input command if (user_command != m) Serial.println(user_comman

10、d); Serial.println(); ack = 0; switch (user_command) /! Prints the appropriate submenu case 1: ack |= menu_1_automatic_mode(mAh_or_Coulombs, celcius_or_kelvin, prescalar_mode, prescalarValue, alcc_mode); /! Automatic Mode break; case 2: ack |= menu_2_scan_mode(mAh_or_Coulombs, celcius_or_kelvin, pre

11、scalar_mode, prescalarValue, alcc_mode); /! Scan Mode break; case 3: ack |= menu_3_manual_mode(mAh_or_Coulombs, celcius_or_kelvin, prescalar_mode, prescalarValue, alcc_mode); /! Manual Mode break; case 4: ack |= menu_4_sleep_mode(mAh_or_Coulombs, prescalar_mode, prescalarValue, alcc_mode); /! Sleep

12、Mode break; case 5: ack |= menu_5_shutdown_mode(); /! Shutdown Mode break; case 6: ack |= menu_6_settings(&mAh_or_Coulombs, &celcius_or_kelvin, &prescalar_mode, &prescalarValue, &alcc_mode); /! Settings Mode break; if (ack != 0) /! If ack is not recieved print an error. Serial.println(ack_error); Se

13、rial.print(F(*); print_prompt(); / Function Definitions/! Print the title blockvoid print_title() Serial.println(F(n*); Serial.print(F(* DC1812A Demonstration Program *n); Serial.print(F(* *n); Serial.print(F(* This program communicates with the LTC2943 Multicell Coulomb *n); Serial.print(F(* Counte

14、r found on the DC1812A demo board. *n); Serial.print(F(* Set the baud rate to 115200 and select the newline terminator.*n); Serial.print(F(* *n); Serial.print(F(*n);/! Print the Promptvoid print_prompt() Serial.print(F(n1-Automatic Moden); Serial.print(F(2-Scan Moden); Serial.print(F(3-Manual Moden)

15、; Serial.print(F(4-Sleep Moden); Serial.print(F(5-Shutdown Moden); Serial.print(F(6-Settingsn); Serial.print(F(Enter a command: );/! Automatic Mode.int8_t menu_1_automatic_mode(int8_t mAh_or_Coulombs, int8_t celcius_or_kelvin ,uint16_t prescalar_mode, uint16_t prescalarValue, uint16_t alcc_mode) /!

16、return Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. int8_t LTC2943_mode; int8_t ack = 0; LTC2943_mode = LTC2943_AUTOMATIC_MODE|prescalar_mode|alcc_mode ; /! Set the control register of the LTC2943 to automatic mode as well as set prescalar an

17、d AL#/CC# pin values. Serial.println(); ack |= LTC2943_write(LTC2943_I2C_ADDRESS, LTC2943_CONTROL_REG, LTC2943_mode); /! Writes the set mode to the LTC2943 control register do Serial.print(F(*nn); uint8_t status_code, hightemp_code, lowtemp_code; uint16_t charge_code, current_code, voltage_code, tem

18、perature_code; ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_ACCUM_CHARGE_MSB_REG, &charge_code); /! Read MSB and LSB Accumulated Charge Registers for 16 bit charge code ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_VOLTAGE_MSB_REG, &voltage_code); /! Read MSB and LSB Voltage R

19、egisters for 16 bit voltage code ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_CURRENT_MSB_REG, ¤t_code); /! Read MSB and LSB Current Registers for 16 bit current code ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_TEMPERATURE_MSB_REG, &temperature_code); /! Read MSB and L

20、SB Temperature Registers for 16 bit temperature code ack |= LTC2943_read(LTC2943_I2C_ADDRESS, LTC2943_STATUS_REG, &status_code); /! Read Status Register for 8 bit status code float charge, current, voltage, temperature; if(mAh_or_Coulombs) charge = LTC2943_code_to_coulombs(charge_code, resistor, pre

21、scalarValue); /! Convert charge code to Coulombs if Coulomb units are desired. Serial.print(Coulombs: ); Serial.print(charge, 4); Serial.print(F( Cn); else charge = LTC2943_code_to_mAh(charge_code, resistor, prescalarValue); /! Convert charge code to mAh if mAh units are desired. Serial.print(mAh: )

22、; Serial.print(charge, 4); Serial.print(F( mAhn); current = LTC2943_code_to_current(current_code, resistor); /! Convert current code to Amperes voltage = LTC2943_code_to_voltage(voltage_code); /! Convert voltage code to Volts Serial.print(F(Current ); Serial.print(current, 4); Serial.print(F( An); S

23、erial.print(F(Voltage ); Serial.print(voltage, 4); Serial.print(F( Vn); if(celcius_or_kelvin) temperature = LTC2943_code_to_kelvin_temperature(temperature_code); /! Convert temperature code to kelvin Serial.print(F(Temperature ); Serial.print(temperature, 4); Serial.print(F( Kn); else temperature =

24、LTC2943_code_to_celcius_temperature(temperature_code); /! Convert temperature code to celcius Serial.print(F(Temperature ); Serial.print(temperature, 4); Serial.print(F( Cn); checkAlerts(status_code); /! Check status code for Alerts. If an Alert has been set, print out appropriate message in the Ser

25、ial Prompt. Serial.print(F(m-Main Menunn); Serial.flush(); delay(AUTOMATIC_MODE_DISPLAY_DELAY); /! Delay for 1s before next polling while (Serial.available() = false | (ack); /! if Serial is not available and an NACK has not been recieved, keep polling the registers. read_int(); / clears the Serial.

26、available return(ack);/! Scan Modeint8_t menu_2_scan_mode(int8_t mAh_or_Coulombs , int8_t celcius_or_kelvin ,uint16_t prescalar_mode,uint16_t prescalarValue, uint16_t alcc_mode)/! return Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge int8_t LTC2

27、943_mode; int8_t ack = 0; LTC2943_mode = LTC2943_SCAN_MODE|prescalar_mode|alcc_mode ; /! Set the control mode of the LTC2943 to scan mode as well as set prescalar and AL#/CC# pin values. Serial.println(); ack |= LTC2943_write(LTC2943_I2C_ADDRESS, LTC2943_CONTROL_REG, LTC2943_mode); /! Writes the set

28、 mode to the LTC2943 control register do Serial.print(F(*nn); uint8_t status_code; uint16_t charge_code, current_code, voltage_code, temperature_code; ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_ACCUM_CHARGE_MSB_REG, &charge_code); /! Read MSB and LSB Accumulated Charge Registers for 16

29、 bit charge code ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_VOLTAGE_MSB_REG, &voltage_code); /! Read MSB and LSB Voltage Registers for 16 bit voltage code ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_CURRENT_MSB_REG, ¤t_code); /! Read MSB and LSB Current Registers for

30、 16 bit current code ack |= LTC2943_read_16_bits(LTC2943_I2C_ADDRESS, LTC2943_TEMPERATURE_MSB_REG, &temperature_code); /! Read MSB and LSB Temperature Registers for 16 bit temperature code ack |= LTC2943_read(LTC2943_I2C_ADDRESS, LTC2943_STATUS_REG, &status_code); /! Read Status Registers for 8 bit stat