ZHCS229C September   2011  – January 2020 BQ24725A

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 SMBus Interface
    4. 8.4 Device Functional Modes
      1. 8.4.1  Adapter Detect and ACOK Output
      2. 8.4.2  Adapter Over Voltage (ACOVP)
      3. 8.4.3  System Power Selection
      4. 8.4.4  Battery LEARN Cycle
      5. 8.4.5  Enable and Disable Charging
      6. 8.4.6  Automatic Internal Soft-Start Charger Current
      7. 8.4.7  High Accuracy Current Sense Amplifier
      8. 8.4.8  Charge Timeout
      9. 8.4.9  Converter Operation
      10. 8.4.10 Continuous Conduction Mode (CCM)
      11. 8.4.11 Discontinuous Conduction Mode (DCM)
      12. 8.4.12 Input Over Current Protection (ACOC)
      13. 8.4.13 Charge Over Current Protection (CHGOCP)
      14. 8.4.14 Battery Over Voltage Protection (BATOVP)
      15. 8.4.15 Battery Shorted to Ground (BATLOWV)
      16. 8.4.16 Thermal Shutdown Protection (TSHUT)
      17. 8.4.17 EMI Switching Frequency Adjust
      18. 8.4.18 Inductor Short, MOSFET Short Protection
    5. 8.5 Register Maps
      1. 8.5.1 Battery-Charger Commands
      2. 8.5.2 Setting Charger Options
        1. Table 3. Charge Options Register (0x12H)
      3. 8.5.3 Setting the Charge Current
        1. Table 4. Charge Current Register (0x14H), Using 10mΩ Sense Resistor
      4. 8.5.4 Setting the Charge Voltage
        1. Table 5. Charge Voltage Register (0x15H)
      5. 8.5.5 Setting Input Current
        1. Table 6. Input Current Register (0x3FH), Using 10mΩ Sense Resistor
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Typical System with Two NMOS Selector
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Negative Output Voltage Protection
          2. 9.2.1.2.2 Reverse Input Voltage Protection
          3. 9.2.1.2.3 Reduce Battery Quiescent Current
          4. 9.2.1.2.4 Inductor Selection
          5. 9.2.1.2.5 Input Capacitor
          6. 9.2.1.2.6 Output Capacitor
          7. 9.2.1.2.7 Power MOSFETs Selection
          8. 9.2.1.2.8 Input Filter Design
          9. 9.2.1.2.9 BQ24725A Design Guideline
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Simplified System without Power Path
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
    3. 9.3 System Examples
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 第三方米6体育平台手机版_好二三四免责声明
    2. 12.2 接收文档更新通知
    3. 12.3 支持资源
    4. 12.4 商标
    5. 12.5 静电放电警告
    6. 12.6 Glossary
  13. 13机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

8.5.3 Setting the Charge Current

To set the charge current, write a 16bit ChargeCurrent() command (0x14H or 0b00010100) using the data format listed in Table 4. With 10mΩ sense resistor, the BQ24725A provides a charge current range of 128mA to 8.128A, with 64mA step resolution. Sending ChargeCurrent() below 128mA or above 8.128A clears the register and terminates charging. Upon POR, charge current is 0A. A 0.1µF capacitor between SRP and SRN for differential mode filtering is recommended, 0.1µF capacitor between SRN and ground for common mode filtering, and an optional 0.1µF capacitor between SRP and ground for common mode filtering. Meanwhile, the capacitance on SRP should not be higher than 0.1µF in order to properly sense the voltage across SRP and SRN for cycle-by-cycle under-current and over current detection.

The SRP and SRN pins are used to sense RSR with default value of 10mΩ. However, resistors of other values can also be used. For a larger sense resistor, a larger sense voltage is given, and a higher regulation accuracy; but, at the expense of higher conduction loss. If the current sensing resistor value is too high, it may trigger an over current protection threshold because the current ripple voltage is too high. In such a case, either a higher inductance value or a lower current sensing resistor value should be used to limit the current ripple voltage level. A current sensing resistor value no more than 20mΩ is suggested.

To provide secondary protection, the BQ24725A has an ILIM pin with which the user can program the maximum allowed charge current. Internal charge current limit is the lower one between the voltage set by ChargeCurrent(), and voltage on ILIM pin. To disable this function, the user can pull ILIM above 1.6V, which is the maximum charge current regulation limit. Equation 2 shows the voltage set on ILIM pin with respect to the preferred charge current limit:

Equation 2. BQ24725A eq1_lusa79.gif
Figure 15. Charge Current Register (0x14H), Using 10mΩ Sense Resistor
15 14 13 12 11 10 9 8
Not in use Not in use Not in use Charge Current, DACICHG 6 Charge Current, DACICHG 5 Charge Current, DACICHG 4 Charge Current, DACICHG 3 Charge Current, DACICHG 2
R/W R/W R/W R/W R/W R/W R/W
7 6 5 4 3 2 1 0
Charge Current, DACICHG 1 Charge Current, DACICHG 0 Not in use Not in use Not in use Not in use Not in use Not in use
R/W R/W R/W R/W R/W R/W R/W R/W
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset

Table 4. Charge Current Register (0x14H), Using 10mΩ Sense Resistor

Bit Field Type Reset Description
[15] Not in use R/W Not used.
[14] Not in use R/W Not used.
[13] Not in use Not used.
[12] Charge Current, DACICHG 6 R/W 0 = Adds 0mA of charger current.
1 = Adds 4096mA of charger current.
[11] Charge Current, DACICHG 5 R/W 0 = Adds 0mA of charger current.
1 = Adds 2048mA of charger current.
[10] Charge Current, DACICHG 4 R/W 0 = Adds 0mA of charger current.
1 = Adds 1024mA of charger current.
[9] Charge Current, DACICHG 3 R/W 0 = Adds 0mA of charger current.
1 = Adds 512mA of charger current.
[8] Charge Current, DACICHG 2 R/W 0 = Adds 0mA of charger current.
1 = Adds 256mA of charger current.
[7] Charge Current, DACICHG 1 R/W 0 = Adds 0mA of charger current.
1 = Adds 128mA of charger current.
[6] Charge Current, DACICHG 0 R/W 0 = Adds 0mA of charger current.
1 = Adds 64mA of charger current.
[5] Not in use R/W Not used.
[4] Not in use R/W Not used.
[3] Not in use R/W Not used.
[2] Not in use R/W Not used.
[1] Not in use R/W Not used.
[0] Not in use R/W Not used.
千亿体育app官网登录(中国)官方网站IOS/安卓通用版/手机APP | 米乐app下载官网（中国）|ios|Android/通用版APP最新版 | 米乐|米乐·M6（中国大陆）官方网站 | 千亿体育登陆地址 | 华体会体育（中国）HTH·官方网站 | 千赢qy国际_全站最新版千赢qy国际V6.2.14安卓/IOS下载 | 18新利网v1.2.5|中国官方网站 | bob电竞真人（中国官网）安卓/ios苹果/电脑版【1.97.95版下载】 | 千亿体育app官方下载(中国)官方网站IOS/安卓/手机APP下载安装 |