ZHCSLN5D december 2010 – september 2020 BQ24133
PRODUCTION DATA
- 1
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 5 Description (continued)
- 6 Device Comparison Table
- 7 Pin Configuration and Functions
- 8 Specifications
-
9 Detailed Description
- 9.1 Overview
- 9.2 Functional Block Diagram
- 9.3
Feature Description
- 9.3.1 Battery Voltage Regulation
- 9.3.2 Battery Current Regulation
- 9.3.3 Battery Precharge Current Regulation
- 9.3.4 Input Current Regulation
- 9.3.5 Charge Termination, Recharge, And Safety Timers
- 9.3.6 Power Up
- 9.3.7 Input Undervoltage Lockout (UVLO)
- 9.3.8 Input Overvoltage/Undervoltage Protection
- 9.3.9 Enable and Disable Charging
- 9.3.10 System Power Selector
- 9.3.11 Converter Operation
- 9.3.12 Automatic Internal Soft-Start Charger Current
- 9.3.13 Charge Overcurrent Protection
- 9.3.14 Charge Undercurrent Protection
- 9.3.15 Battery Detection
- 9.3.16 Battery Short Protection
- 9.3.17 Battery Overvoltage Protection
- 9.3.18 Temperature Qualification
- 9.3.19 MOSFET Short Circuit and Inductor Short Circuit Protection
- 9.3.20 Thermal Regulation and Shutdown Protection
- 9.3.21 Timer Fault Recovery
- 9.3.22 Charge Status Outputs
- 9.4 Device Functional Modes
- 10Application and Implementation
- 11Power Supply Recommendations
- 12Layout
- 13Device and Documentation Support
- 14Mechanical, Packaging, and Orderable Information
9.3.2 Battery Current Regulation
The ISET input sets the maximum charging current. Battery current is sensed by current sensing resistor RSR connected between SRP and SRN. The equation for charge current is:
Equation 1. 
The valid input voltage range of ISET is up to 0.5 V. With 10-mΩ sense resistor, the maximum output current is 2.5 A.
The charger is disabled when ISET pin voltage is below 40 mV and is enabled when the ISET pin voltage is above 120 mV. For 10-mΩ current sensing resistor, the minimum fast charge current must be higher than 600 mA.
Under high ambient temperature, the charge current will fold back to keep IC temperature not exceeding 120°C.