Charge Pump Clock Selection for Low-Ripple Voltage Regulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional charge pump voltage regulation methods in flash memory devices suffer from poor accuracy, instability, and ripple due to direct grounding or frequent disabling of the clock frequency, affecting the reliability of flash memory cells.
Innovation Solution
A charge pump voltage regulator circuit that utilizes an oscillating frequency source, Mux circuit, charge pump, voltage divider, and comparator to dynamically select a driving clock frequency based on voltage comparisons, reducing ripple and improving regulation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the output of the charge pump is directly grounded to discharge unwanted electricity, then the output voltage can be pulled down to a desired level, but this interrupts provision of the output voltage and adds ripple to the subsequent output voltage
Solution Approach 1:
The patent introduces an intermediary discharge path through a discharge transistor connected to a discharge node, rather than directly grounding the charge pump output. This intermediary structure allows controlled discharge of unwanted electricity while maintaining continuous voltage provision to the output, thereby reducing ripple and improving voltage stability while still achieving accurate voltage regulation.
2Measurement precision
If the driving clock frequency is frequently enabled and disabled to regulate output voltage, then voltage regulation can be achieved, but the charge pump operates only in discharging and normal conditions resulting in poor voltage regulation accuracy and long restart times
Solution Approach 1:
The patent implements dynamic control of the charge pump by adjusting the driving clock frequency in a stepped manner based on voltage comparison results, rather than simply enabling and disabling it. The Mux circuit selects from multiple oscillating frequencies to dynamically adapt the charge pump operation, allowing smooth transitions between operating states and eliminating long restart times while maintaining accurate voltage regulation.
Solution Approach 2:
The patent employs periodic voltage comparison and corresponding periodic adjustment of the driving clock frequency to regulate output voltage. The comparator continuously compares the divided output voltage with a reference voltage, and based on the comparison result, the Mux circuit periodically switches between different frequency options, creating a controlled periodic action that maintains stable voltage without frequent enable-disable cycles.
3Reliability
If multiple oscillating frequencies are used to drive the charge pump, then more accurate voltage regulation with less ripple can be achieved, but the device complexity increases due to additional circuits
Solution Approach 1:
The patent segments the voltage regulation function into distinct modular components: an oscillating frequency source circuit providing multiple frequencies, a Mux circuit for frequency selection, a voltage divider circuit, and a comparator circuit. This segmentation allows each component to perform a specific function efficiently, achieving accurate voltage regulation with reduced ripple while keeping the overall circuit design organized and manageable despite the increased complexity.
Data Source
AI summary
A charge pump voltage regulator circuit is provided. The charge pump voltage regulator circuit includes: an oscillating frequency source circuit for providing multiple oscillating frequencies; a Mux circuit for receiving the oscillating frequencies and a control signal, selecting one of the oscillating frequencies as a driving clock frequency based on a value of the control signal and outputting the driving clock frequency, wherein each oscillating frequency corresponds to a corresponding value of the control signal; a charge pump for raising an input voltage to a value corresponding to the driving clock frequency and outputting a voltage; a voltage divider circuit for dividing the voltage output from the charge pump to obtain multiple divided voltages; and a comparator circuit for comparing each divided voltage with a reference voltage to obtain multiple comparison values, which are taken as the control signal for the Mux circuit.