LDO Power Supply Control for Mobile Terminals
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Solution Overview
Problem
Current power management chips in mobile terminals face challenges in achieving zero power consumption while maintaining performance, as existing power-saving methods often compromise other terminal functions and do not fully reduce power consumption.
Innovation Solution
The apparatus and method involve a power supply control system that dynamically adjusts the operating mode of a low dropout regulator (LDO) by selecting between USBIN and ACIN voltages and using a voltage detecting circuit to provide an enable signal, allowing the LDO to operate in different modes based on threshold voltages, thereby minimizing current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If complex control logics are added to implement power saving management, then power consumption is reduced, but device complexity increases
Solution Approach 1:
The patent changes the operating parameters of the LDO by dynamically adjusting the reference voltage level. When USB charging is detected, the reference voltage is lowered to enable the LDO to enter a lower power consumption mode. This parameter change allows the system to reduce power consumption without adding complex control logic, as the LDO automatically adapts to the changed reference voltage level.
2Use of energy by moving object
If power consumption is reduced to achieve zero power consumption, then energy efficiency is improved, but other terminal performances are influenced
Solution Approach 1:
The patent implements dynamic operation of the LDO by enabling it to switch between different operating modes based on the charging state. When USB charging is detected, the LDO dynamically adjusts its reference voltage and enters a lower power consumption mode. When USB charging is not present, it automatically returns to normal operation. This dynamic adaptation ensures that power consumption is reduced only when appropriate, without compromising terminal performance.
Solution Approach 2:
The system uses the presence or absence of USB voltage as a self-triggering condition that automatically controls the LDO's operating mode. The detection circuit identifies USB charging status and the LDO autonomously adjusts its reference voltage and power consumption level without requiring external intervention. This self-service mechanism ensures that power saving is achieved naturally based on actual usage conditions, maintaining terminal performance when needed.
3Stability of the object's composition
If LDO operates in regulation mode to provide stable voltage, then voltage stability is improved, but power consumption increases
Solution Approach 1:
The patent changes the reference voltage parameter of the LDO based on the charging state. When USB charging is detected, the reference voltage is lowered, allowing the LDO to operate in a lower power consumption mode while still providing adequate voltage regulation. This parameter change enables the system to trade some voltage regulation precision for reduced power consumption during USB charging, when the battery is being charged and voltage stability requirements are less critical.
Data Source
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AI summary
Apparatuses and methods for controlling a power supply are provided. First power supply selecting circuit selects a higher voltage from USBIN and ACIN to be first output voltage; first LDO decreases the first output voltage to second output voltage, and closes self-start circuit after receiving reference voltage; second power supply selecting circuit selects a higher voltage from second output voltage and VBAT to be third output voltage; second LDO supplies the third output voltage as the first input voltage to reference circuit; reference circuit outputs the reference voltage according to first input voltage; second LDO closes self-start circuit after receiving the reference voltage; voltage detecting circuit supplies an enable signal to second LDO when determining that USBIN orACIN reaches a threshold voltage according to the reference voltage; and second LDO provides the first input voltage to reference circuit after receiving the enable signal.