Charge Pump Circuit Protection for Intermediate Node Electrification
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Solution Overview
Problem
In charge pump circuits, the lack of a suitable leakage path for intermediate nodes of series-coupled capacitors can lead to device destruction due to electrification and reduced pump efficiency from leakage currents.
Innovation Solution
A protection circuit is implemented at the series coupling node of the capacitors, which is conductive when the step-up voltage is not generated to discharge stored charge and non-conductive when it is generated, using diodes or MOS transistors to control the leakage path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If two capacitors are coupled in series to form one step-up capacitor, then the withstand voltage of the step-up capacitor is relaxed (voltage per capacitor is reduced), but the intermediate node may become electrified causing device destruction
Solution Approach 1:
A protection circuit is introduced as an intermediary element between the series-coupled capacitors. This protection circuit includes a discharge path with a switching element that actively manages the intermediate node, preventing electrification while maintaining the voltage division benefit of series coupling.
2Reliability
If a leakage path is provided for the intermediate node, then electrification is prevented, but pump efficiency decreases due to leakage current
Solution Approach 1:
The protection circuit employs a switching element that dynamically changes its state based on operational requirements. During normal operation, the switch is open to prevent leakage current and maintain pump efficiency. When electrification risk is detected, the switch closes to provide a discharge path, thus adaptively balancing reliability and productivity.
3Productivity
If no leakage path is provided for the intermediate node, then pump efficiency is maintained, but the intermediate node may become electrified leading to device destruction
Solution Approach 1:
A protection circuit is introduced as an intermediary element between the series-coupled capacitors. This protection circuit includes a discharge path with a switching element that actively manages the intermediate node, preventing electrification while maintaining the voltage division benefit of series coupling.
4Reliability
If a protection circuit is added to manage the intermediate node, then device destruction is prevented, but circuit complexity increases
Solution Approach 1:
A protection circuit is introduced as an intermediary element between the series-coupled capacitors. This protection circuit includes a discharge path with a switching element that actively manages the intermediate node, preventing electrification while maintaining the voltage division benefit of series coupling.
Solution Approach 2:
The protection circuit is designed to automatically detect and respond to electrification conditions without external intervention. The switching element self-activates when voltage thresholds are exceeded, eliminating the need for complex control logic or external monitoring systems.
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
This configuration prevents device destruction and maintains pump efficiency by managing voltage levels and preventing leakage currents during operation.
Implementation Method 1
a protection circuit coupled to a series coupling node of the first capacitance and the second capacitance. The protection circuit is set in a conductive state and discharges a stored charge at the series coupling node of the first capacitance and the second capacitance, when the step-up voltage is not generated
Implementation Method 2
a step-up capacitor including a first capacitance and a second capacitance coupled in series with each other, a capacitance driver capable of generating step-up voltage by driving the step-up capacity
Data Source
AI summary
Improvement technology of a charge pump circuit is provided for avoiding device destruction due to electrification of an intermediate node of plural capacitors coupled in series to form one step-up capacitor, and avoiding reduction of pump efficiency due to leakage current which flows through a leakage path of the intermediate node concerned. A charge pump circuit includes a step-up capacitor configured by a first capacitance and a second capacitance coupled in series, a capacitance driver, and a protection circuit. The protection circuit is set at a conductive state and discharges a stored charge at the series coupling node of the first capacitance and the second capacitance, when the step-up voltage is not generated, and the protection circuit is maintained in a non-conductive state, when the step-up voltage is generated. Accordingly, relaxation of the withstand voltage of the step-up capacitor is achieved, and reduction of the pump efficiency is avoided.