Single Capacitor Charge Pump Circuit for Low Leakage Voltage Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional charge pumps require multiple capacitors and switches, occupying significant real estate in integrated circuits, making it challenging to reduce the size of the charge pump circuit while generating higher voltage levels from a reduced supply voltage.
Innovation Solution
A single capacitor charge pump circuit using a transistor and delay circuitry to generate higher peak voltage values, with the capacitor acting as both a flywheel and reservoir, reducing the circuit's size and minimizing leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple capacitors and switches are used in conventional charge pumps, then higher voltage levels can be generated from reduced supply voltage, but the real estate occupied in the integrated circuit increases significantly
Solution Approach 1:
The patent combines multiple capacitors into a single capacitor that performs multiple functions. The first and second capacitors of conventional charge pumps are merged into one capacitor that alternates between storing charge during the charging phase and providing charge during the discharge phase, thereby reducing the total capacitor count and occupied area while maintaining voltage multiplication capability
Solution Approach 2:
The single capacitor in the patent serves multiple functions that were previously distributed among multiple capacitors. It acts as both the flying capacitor for voltage multiplication and the reservoir for charge storage, dynamically switching between these roles through controlled charging and discharging cycles, thus eliminating the need for separate dedicated capacitors
2Ease of operation
If multiple switches are used in conventional charge pumps, then voltage switching and charge transfer can be controlled, but the device complexity and real estate requirements increase
Solution Approach 1:
The patent merges the functions of multiple switches into a single switch that controls both charge transfer and voltage switching. The switch alternates between connecting the capacitor to the input voltage source for charging and connecting it to the output for discharge, thereby maintaining controlled voltage multiplication with reduced switch count and lower device complexity
3Area of stationary object
If a single capacitor is used for both flywheel and reservoir functions, then real estate requirements are reduced, but leakage current may increase
Solution Approach 1:
The patent employs periodic charging and discharging cycles where the single capacitor is charged during one phase and discharged during another. This periodic operation allows the capacitor to reset its voltage state regularly, minimizing the accumulation of leakage current effects and enabling the single capacitor to effectively serve both flywheel and reservoir functions without excessive leakage
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 doubles the input voltage with reduced real estate requirements and minimized leakage current, enabling efficient voltage generation for IC components.
Implementation Method 1
uses one capacitor, a transistor, and appropriately connected delay circuitry to generate a signal having a higher peak voltage value than the input signal
Data Source
AI summary
A charge pump circuit includes a delay circuit, a transistor, and a capacitor. The charge pump receives an input signal and outputs an output signal. The delay circuit receives a first signal based on the input signal and outputs a first delayed signal. The transistor includes a gate, a first channel node, and a second channel node. The first channel node receives the first signal. The second channel node is connected to the output and to a first plate of the capacitor. A second plate of the capacitor receives a second signal based on the first delayed signal. The charge pump circuit is adapted to operate such that the voltage range of the output signal is greater than the voltage range of the input signal.