ZHCSKL0D December 2009 – December 2019 BQ24610 , BQ24617
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 说明 （续）
- 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 Input Adapter Current Regulation
- 9.3.4 Precharge
- 9.3.5 Charge Termination, Recharge, and Safety Timer
- 9.3.6 Power Up
- 9.3.7 Enable and Disable Charging
- 9.3.8 System Power Selector
- 9.3.9 Automatic Internal Soft-Start Charger Current
- 9.3.10 Converter Operation
- 9.3.11 Synchronous and Nonsynchronous Operation
- 9.3.12 Cycle-by-Cycle Charge Undercurrent Protection
- 9.3.13 Input Overvoltage Protection (ACOV)
- 9.3.14 Input Undervoltage Lockout (UVLO)
- 9.3.15 Battery Overvoltage Protection
- 9.3.16 Cycle-by-Cycle Charge Overcurrent Protection
- 9.3.17 Thermal Shutdown Protection
- 9.3.18 Temperature Qualification
- 9.3.19 Timer Fault Recovery
- 9.3.20 PG Output
- 9.3.21 CE (Charge Enable)
- 9.3.22 Charge Status Outputs
- 9.3.23 Battery Detection
- 9.4 Device Functional Modes
- 10Application and Implementation
- 11Power Supply Recommendations
- 12Layout
- 13器件和文档支持
- 14机械、封装和可订购信息
封装选项
机械数据 (封装 | 引脚)
- RGE|24
散热焊盘机械数据 (封装 | 引脚)
- RGE|24
订购信息
10.2.1.2.1 Inductor Selection
The BQ2461x has 600-kHz switching frequency to allow the use of small inductor and capacitor values. Inductor saturation current should be higher than the charging current (ICHG) plus half the ripple current (IRIPPLE):
The inductor ripple current depends on input voltage (VIN), duty cycle (D = VOUT/VIN), switching frequency (fs) and inductance (L):
The maximum inductor ripple current happens with D = 0.5 or close to 0.5. For example, the battery charging voltage range is from 9 V to 12.6 V for a 3-cell battery pack. For 20-V adapter voltage, 10-V battery voltage gives the maximum inductor ripple current. Another example is a 4-cell battery, the battery voltage range is from 12 V to 16.8 V, and 12-V battery voltage gives the maximum inductor ripple current.
Usually inductor ripple is designed in the range of (20%–40%) maximum charging current as a trade-off between inductor size and efficiency for a practical design.
The BQ2461x has cycle-by-cycle charge undercurrent protection (UCP) by monitoring the charging-current sensing resistor to prevent negative inductor current. The typical UCP threshold is 5-mV falling edge corresponding to 0.5-A falling edge for a 10-mΩ charging-current sensing resistor.