Display Power Circuit With Load-Adaptive Voltage Feedback
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Solution Overview
Problem
The existing power circuits for display devices face challenges in maintaining a stable voltage range for digital circuits when load changes occur, leading to potential damage or malfunction due to IR drops, and result in increased power consumption.
Innovation Solution
A power circuit with a current sensing resistor, sensing part, and voltage generation part, including a buck converter, that adjusts the output voltage based on current changes to maintain a stable voltage range and reduce power consumption by using differential amplifiers and PWM control signals to manage the voltage applied to the digital circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the PMIC increases the voltage of VDD in consideration of the IR drop of VDD, then the voltage stability is improved, but the VDD voltage applied to the DDIC instantaneously increases when a load suddenly decreases, which may cause damage or malfunction of the DDIC
Solution Approach 1:
The patent implements a feedback mechanism where the sensing part continuously monitors the current flowing through the current sensing resistor and adjusts the output voltage accordingly. When load current decreases, the feedback signal triggers the voltage generation part to lower the output voltage, preventing voltage spikes that could damage the DDIC while maintaining stable voltage under heavy load conditions.
Solution Approach 2:
The patent makes the output voltage dynamic by continuously adjusting it based on real-time current sensing. The voltage generation part responds to current changes by dynamically modifying the output voltage level, transitioning from a static voltage supply to an adaptive system that optimizes voltage output according to actual load conditions.
2Reliability
If the PMIC maintains the output voltage constant through a feedback path when the current of an output terminal is large, then the voltage drop is reduced, but the device complexity increases
Solution Approach 1:
The patent combines the voltage regulation and current sensing functions into a single integrated circuit. The sensing part, voltage generation part, and control logic are merged within the PMIC, eliminating the need for separate external components and reducing overall system complexity while maintaining voltage stability under heavy load conditions.
3Reliability
If a separate power source (VDDI) is added to prevent voltage drop below operating rate, then the reliability is improved, but the power consumption increases
Solution Approach 1:
The patent makes the single power source VDD multi-functional by enabling it to serve both as the primary power supply and as a regulated voltage source that adapts to different load conditions. The voltage generation part ensures VDD remains within the operating rate voltage range regardless of load variations, eliminating the need for a separate VDDI while maintaining operational reliability and reducing power consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively stabilizes the voltage applied to digital circuits within a safe range, preventing damage and optimizing power consumption by dynamically adjusting the output voltage in response to load changes.
Implementation Method 1
a current sensing resistor connected to the output terminal
Implementation Method 2
a sensing part configured to receive a first reference voltage and voltages of both ends of the current sensing resistor and vary one of a feedback voltage and a second reference voltage
Implementation Method 3
a voltage generation part configured to receive the feedback voltage and the second reference voltage and lowers the output voltage when a current flowing through the current sensing resistor decreases
Data Source
AI summary
The present disclosure relates to a power circuit and a display device including the same. The power circuit includes an output terminal configured to supply an output voltage to a digital circuit; a current sensing resistor connected to the output terminal; a sensing part configured to receive a first reference voltage and voltages of both ends of the current sensing resistor and vary one of a feedback voltage and a second reference voltage; and a voltage generation part configured to receive the feedback voltage and the second reference voltage and lowers the output voltage when a current flowing through the current sensing resistor decreases.