Charge Pump Slew Rate Control for Non-Volatile Memory Programming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-volatile memory cells face durability and efficiency issues due to improper selection of program and erase voltages, and the slew rate of charge pumps affects the reliability of these operations.
Innovation Solution
A charge pump regulator is introduced to monitor and control the output voltage slew rate of charge pumps during program and erase operations, ensuring it falls within a desired range through feedback mechanisms, adjusting the clock signal frequency to maintain optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the high voltage is applied for a longer duration during program or erase cycles, then the program and erase efficiency is improved, but the durability of the non-volatile memory cell deteriorates
Solution Approach 1:
The patent implements a feedback mechanism that monitors the output voltage of the charge pump and adjusts the clock signal frequency accordingly. A sense current generator measures the slew rate by detecting the current through a sense capacitor, and this information feeds back to the clock generator to dynamically adjust the operating frequency, ensuring optimal balance between efficiency and durability
Solution Approach 2:
The patent dynamically changes the operating parameters of the charge pump by adjusting the clock signal frequency based on the monitored slew rate. This parameter adjustment allows the system to optimize the voltage application duration and rate, achieving efficient programming and erasing while preventing memory cell degradation
2Reliability
If the high voltage is applied for a shorter duration during program or erase cycles, then the durability of the non-volatile memory cell is improved, but the program and erase efficiency deteriorates
Solution Approach 1:
The feedback loop continuously monitors the charge pump output and adjusts the clock frequency to maintain optimal operation. This ensures that the high voltage is applied for the precise duration needed to achieve efficient programming and erasing without excessive time that would degrade memory cell durability
Solution Approach 2:
The system dynamically adjusts the charge pump operating frequency during operation based on real-time slew rate measurements. This dynamic adaptation allows the system to optimize each program/erase cycle individually, balancing efficiency and durability requirements
3Device complexity
If the slew rate of the charge pump output voltage is not controlled, then the device complexity is reduced, but the reliability of program and erase operations deteriorates
Solution Approach 1:
The patent introduces a feedback control system that monitors the charge pump output voltage slew rate and adjusts the clock signal frequency accordingly. This feedback mechanism ensures reliable program and erase operations by maintaining optimal slew rate conditions without requiring overly complex external control circuitry
Solution Approach 2:
The charge pump system performs self-regulation by using its own output voltage to generate the sense current that controls its operating frequency. The slew rate generator uses the charge pump's output to create feedback that automatically adjusts the clock frequency, making the system self-regulating with minimal external intervention
Data Source
AI summary
An integrated circuit includes a non-volatile memory, a charge pump that generates high voltages for programming operations of the non-volatile memory array, and a charge pump regulator that controls a slew rate of the charge pump. The charge pump regulator generates a sense current indicative of the slew rate and adjusts a frequency of a clock signal provided to the charge pump based on the sense current.