ZHCSDI4D March 2015 – October 2022 BQ25890 , BQ25892
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 說明（續）
- 6 Device Comparison Table
- 7 Pin Configuration and Functions
- 8 Specifications
-
9 Detailed Description
- 9.1 Functional Block Diagram
- 9.2
Feature Description
- 9.2.1 Device Power-On-Reset (POR)
- 9.2.2 Device Power Up from Battery without Input Source
- 9.2.3 Device Power Up from Input Source
- 9.2.4 Input Current Optimizer (ICO)
- 9.2.5 Boost Mode Operation from Battery
- 9.2.6 Power Path Management
- 9.2.7 Battery Charging Management
- 9.2.8 Battery Monitor
- 9.2.9 Status Outputs ( PG, STAT, and INT)
- 9.2.10 BATET (Q4) Control
- 9.2.11 Current Pulse Control Protocol
- 9.2.12 Input Current Limit on ILIM
- 9.2.13 Thermal Regulation and Thermal Shutdown
- 9.2.14 Voltage and Current Monitoring in Buck and Boost Mode
- 9.2.15 Battery Protection
- 9.2.16 Serial Interface
- 9.3 Device Functional Modes
- 9.4 Register Maps
- 10Application and Implementation
- 11Power Supply Recommendations
- 12Layout
- 13Device and Documentation Support
- 14Mechanical, Packaging, and Orderable Information
9.2.6.2 Dynamic Power Management
To meet maximum current limit in USB spec and avoid over loading the adapter, the device features Dynamic Power Management (DPM), which continuously monitors the input current and input voltage. When input source is over-loaded, either the current exceeds the input current limit (IINLIM or IDPM_LIM) or the voltage falls below the input voltage limit (VINDPM). The device then reduces the charge current until the input current falls below the input current limit and the input voltage rises above the input voltage limit.
When the charge current is reduced to zero, but the input source is still overloaded, the system voltage starts to drop. Once the system voltage falls below the battery voltage, the device automatically enters the Section 9.2.6.3 where the BATFET turns on and battery starts discharging so that the system is supported from both the input source and battery.
During DPM mode, the status register bits VDPM_STAT (VINDPM) and/or IDPM_STAT (IINDPM) is/are set high. Figure 9-3 shows the DPM response with 9V/1.2A adapter, 3.2-V battery, 2.8-A charge current and 3.4-V minimum system voltage setting.
Figure 9-3 DPM Response