Digital Charge Pump Control via Cascode Transistors
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Solution Overview
Problem
Conventional charge pumps rely on analog control of clock cycles for voltage regulation, limiting their ability to achieve full-chip control and efficiency in voltage management.
Innovation Solution
A charge pump system that generates digital control signals using a differential amplifier, oscillating circuit, cascode transistors, and an inverter to control a current sink, allowing for precise turn-on and turn-off of the current sink based on feedback voltage levels, enabling faster output control and energy savings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If analog control is used to regulate clock cycles for charge pump voltage control, then voltage regulation is achieved, but full-chip control and system efficiency are limited
Solution Approach 1:
The patent replaces the analog control mechanism with a digital control system. A differential amplifier compares the feedback voltage with a reference voltage and generates a digital control signal based on the comparison result. This digital signal directly controls the charge pump operation, enabling full-chip control while simplifying the overall system architecture by eliminating complex analog control circuits.
2Use of energy by moving object
If the current sink remains continuously on for voltage regulation, then voltage control is maintained, but energy efficiency is reduced
Solution Approach 1:
The patent implements periodic action by using a digital control signal that turns the current sink on and off based on voltage comparison results. When the feedback voltage exceeds the reference voltage, the digital signal activates the current sink to discharge excess charge. When the voltage is sufficient, the current sink is turned off to conserve energy. This periodic operation maintains voltage regulation stability while significantly improving energy efficiency.
3Speed
If analog control signals are used for charge pump regulation, then voltage control is achieved, but control speed is limited
Solution Approach 1:
The patent substitutes analog control signals with digital control signals generated by a differential amplifier. The differential amplifier provides precise voltage comparison between feedback and reference voltages, generating clean digital signals that can be rapidly processed and executed. This digital approach increases control speed while the differential amplifier's inherent precision ensures accurate voltage comparison, simultaneously improving both speed and measurement precision.
Data Source
AI summary
A charge pump system includes: a differential amplifier, for receiving a feedback voltage and a reference voltage and generating an output signal; an oscillating circuit for generating clock pulses; a charge pump for receiving the clock pulses and generating an output voltage; a current sink coupled to the output of the charge pump; a first pair of cascode transistors for generating a digital signal; and an inverter for inverting the digital signal to generate a first digital signal according to the output signal, wherein the first digital signal is input to the current sink. When the feedback voltage is higher than the reference voltage, the first digital signal will be generated and the current sink will be turned on, and when the feedback voltage is lower than the reference voltage, the first digital signal will not be generated and the current sink will be turned off.