ZHCSJZ6F June 2019 – February 2025 BQ25618 , BQ25619
PRODUCTION DATA
- 1
- 1 特性
- 2 應用
- 3 說明
- 4 說明（續）
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 Power-On-Reset (POR)
- 7.3.2 Device Power Up From Battery Without Input Source
- 7.3.3 Power Up From Input Source
- 7.3.4 Boost Mode Operation From Battery
- 7.3.5 Power Path Management
- 7.3.6 Battery Charging Management
- 7.3.7 Ship Mode and QON Pin
- 7.3.8 Status Outputs (STAT, INT , PMID_GOOD)
- 7.3.9 Protections
- 7.3.10 Serial Interface
- 7.4 Device Functional Modes
- 7.5 Register Maps
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Revision History
- 13Mechanical, Packaging, and Orderable Information
8.2.2.1 Inductor Selection
The 1.5-MHz switching frequency allows the use of small inductor and capacitor values to maintain an inductor saturation current higher than the charging current (ICHG) plus half the ripple current (IRIPPLE):
The inductor ripple current depends on the input voltage (VVBUS), the duty cycle (D = VBAT/VVBUS), the switching frequency (fS) and the inductance (L).
The maximum inductor ripple current occurs when the duty cycle (D) is 0.5 or approximately 0.5. Usually inductor ripple is designed in the range between 20% and 40% maximum charging current as a trade-off between inductor size and efficiency for a practical design.
For compact solution size and efficiency at high current, a 1-μH inductor is recommended. To achieve better light load efficiency during boost mode (output current below 500 mA), the device also supports a 2.2-μH inductor with a 10-μF (min) cap on the system.