Regulated Charge Pump Circuit for Voltage Regulation
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Solution Overview
Problem
Charge pump circuits face inaccuracies in voltage difference due to manufacturing deviations, leading to a large spread in output voltage, which affects the accuracy of voltage regulation.
Innovation Solution
A regulated charge pump circuit comprising a charge pump, first and second level shifters, a voltage follower, and a current mirror, which generates a voltage difference by applying bias and difference currents to determine an accurate output voltage, allowing for a smaller output capacitor and reduced costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If zener diodes with or without series resistor are used to determine voltage difference, then the circuit structure is simple, but manufacturing deviations cause inaccurate voltage difference and large output voltage spread
Solution Approach 1:
The patent implements a feedback mechanism where the output voltage is sensed through level shifters, compared with the input voltage, and the difference current is fed back to the charge pump to adjust the charging current. This closed-loop feedback system automatically compensates for manufacturing deviations, ensuring accurate voltage difference without requiring high-precision components.
Solution Approach 2:
The circuit uses its own output voltage to generate the feedback signal through the level shifters and voltage follower. The system self-regulates by using the voltage difference itself to control the charging current, eliminating the need for external precision reference components and achieving self-correcting operation.
2Stability of the object's composition
If larger output capacitor is used to compensate for voltage spread, then output voltage stability is improved, but circuit cost and size increase
Solution Approach 1:
The feedback mechanism continuously monitors and adjusts the charging current to maintain stable output voltage. This active regulation eliminates the need for large output capacitors that would be required for passive voltage stabilization, achieving stability through control rather than energy storage.
Solution Approach 2:
The patent dynamically changes the charging current parameter based on the detected voltage difference. By adjusting this key parameter in real-time, the system maintains output stability without relying on large capacitor values, thereby reducing component size and cost.
Data Source
AI summary
A circuit includes a charge pump, a first level shifter, a second level shifter, a voltage follower and a current mirror. The charge pump is configured to generate a voltage difference between the input node and the output node. The first level shifter is coupled to the charge pump output and configured to apply a first voltage variation to the charge pump output in response to a bias current. The second level shifter is coupled to the input node and configured to apply a second voltage variation to the charge pump input. The voltage follower is configured to equalize outputs from the first and second level shifters and provide a difference current which is multiplied by the current multiplier to generate a charging current applied to the charge pump.