Charge Pump Voltage Inversion Using Ping-Pong Phase Switching
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Solution Overview
Problem
Conventional charge pumps in OLED display panels are unable to achieve optimal charge transfer as they fail to provide output voltages that are (−⅔) times the input voltage, limiting their efficiency.
Innovation Solution
A charge pump design utilizing ten switches and three capacitors, operating in two modes to provide output voltages that are (−½) and (−⅔) times the input voltage, with a phase switching method called 'ping-pong' to enhance charge transfer in the second mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional charge pump circuit configuration is used, then the circuit structure is simple, but the output voltage cannot achieve (−2⁄3) times the input voltage and charge transfer efficiency is suboptimal
Solution Approach 1:
The charge pump circuit is divided into multiple operational phases (first phase period and second phase period) with different switch configurations. During the first phase period, switches SW1, SW3, SW5, and SW8 are conductive while others are nonconductive. During the second phase period, switches SW2, SW3, SW4, SW7, and SW10 are conductive. This temporal segmentation enables the circuit to achieve (−2⁄3) times voltage multiplication while managing complexity through controlled operation sequences.
Solution Approach 2:
The circuit employs dynamic switch control where the conductivity state of each switch changes between phase periods. The ping-pong phase switching method dynamically reconfigures the capacitor connections - C1 and C3 are charged during the first phase, then discharged during the second phase, creating a dynamic charge transfer process that achieves optimal efficiency.
2Productivity
If the charge pump uses more switches and capacitors to achieve better charge transfer, then the charge transfer efficiency improves, but the number of components increases
Solution Approach 1:
Each capacitor (C1, C2, C3) serves multiple functions across different phase periods. For example, C1 is charged from VIN during the first phase and then discharged to contribute to VOUT during the second phase. The switches serve dual purposes of controlling charge flow paths and enabling voltage multiplication. This multi-functionality allows the circuit to achieve (−2⁄3) times voltage ratio with only three capacitors and ten switches, rather than requiring additional components.
Solution Approach 2:
The charge pump maintains continuous useful action through the ping-pong phase switching method. While one set of capacitors is charging during the first phase period, another set is discharging during the second phase period, ensuring uninterrupted charge transfer to the output. This continuous operation maximizes productivity without requiring redundant components to handle idle periods.
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 allows for efficient charge transfer by reducing the number of components needed while achieving the desired output voltages, with the second mode achieving the best charge transfer through the 'ping-pong' phase switching method.
Implementation Method 1
The charge pump is a DC-DC converter using the capacitor to store power and used for generating the output voltage higher than the input voltage
Data Source
AI summary
A charge pump and operating method thereof are disclosed. The charge pump includes a first capacitor to a third capacitor and a first switch to a tenth switch. The charge pump is used to receive an input voltage and provide an output voltage to a load capacitor. When the charge pump is operated in a first mode, the charge pump controls the second capacitor failure, the output voltage and the input voltage have opposite electricity and the output voltage is (−½) times the input voltage. When the charge pump is operated in a second mode, the charge pump controls the second capacitor failure, the output voltage and the input voltage have opposite electricity and the output voltage is (−⅔) times the input voltage.