Power Management Unit Over-Discharge State Control
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Solution Overview
Problem
Mobile devices face issues with stable system start-up when using newly developed battery packs with higher voltage levels, as the safety switch's reset voltage is higher than the original battery's, leading to failed attempts to switch to active state due to inrush currents, causing the system to repeatedly return to standby during charging.
Innovation Solution
A power management unit that detects the safety switch state and inhibits the transition to active state until the battery voltage exceeds a predefined monitor level, ensuring stable system start-up by controlling charging and monitoring the battery voltage, without requiring additional external components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the power management unit transitions to active state immediately during charging, then the charging speed is improved, but the system stability deteriorates due to repeated state transitions caused by inrush currents
Solution Approach 1:
The system performs preliminary detection of the battery safety switch state before allowing transitions to active state. This preliminary action prevents premature state transitions that would cause inrush currents and subsequent stability issues. The PMU checks the safety switch status in advance and only transitions to active state when conditions are favorable, maintaining both charging efficiency and system stability.
2Measurement precision
If additional external components are added to monitor battery state, then the detection precision is improved, but the device complexity and cost increase
Solution Approach 1:
The power management unit is designed to perform multiple functions: it monitors battery voltage, detects the safety switch state, controls charging operations, and manages state transitions. By making the PMU multi-functional, the patent achieves precise battery state detection without adding separate dedicated monitoring components, thus improving detection precision while avoiding increased device complexity and cost.
Solution Approach 2:
The power management unit uses its existing internal circuitry to detect the battery safety switch state and monitor battery conditions. The system serves itself by utilizing the PMU's built-in capabilities rather than requiring external monitoring components, achieving accurate battery state detection without increasing overall device complexity.
Data Source
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AI summary
A method of operating battery power management unit (PMU) in over- discharge situation is disclosed. Furthermore, a power management unit (PMU) and a device comprising a power management unit (PMU) are disclosed. The power management unit (PMU) is part of a system, comprising a battery and a safety circuit connected to the battery. The state of the safety circuit of the battery is determined and the on/off control of the device is made inactive while the safety circuit remains active. Thereby avoiding an application run on the device to go into an active state, i.e. to be turned on, at a moment when the battery has not returned to its normal operation mode.