Charge Pump Clock Frequency Regulation for Ramp Rate Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Charge pumps face challenges in maintaining accurate output voltage levels due to variations in ramp rates across different elements and conditions, leading to issues like hot electron injection and read disturbs in non-volatile memory devices, as existing designs prioritize minimum recovery rates over maximum ramp rates.
Innovation Solution
A trimmable clock frequency system for charge pumps is introduced, where the clock frequency is adjusted to ensure the ramp rate falls within a predetermined range, using a clock circuit, regulator circuit, and count/comparison circuitry to determine and adjust the number of clock cycles for recovery, thereby controlling the ramp rate and preventing excessive speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the charge pump operates with a high clock frequency to achieve fast recovery, then the recovery speed is improved, but the ramp rate becomes excessive causing hot electron injection and read disturbs
Solution Approach 1:
The charge pump system dynamically adjusts the clock frequency based on the detected ramp rate. The system transitions from a fixed frequency operation to a variable frequency operation where the clock frequency is modulated to maintain the ramp rate within safe boundaries, preventing hot electron injection while ensuring adequate recovery speed.
Solution Approach 2:
The system implements a feedback mechanism where the ramp rate is continuously monitored during the recovery phase. Based on this feedback, the control logic adjusts the clock frequency to ensure the ramp rate remains below the maximum threshold. This closed-loop control prevents excessive ramp rates that would cause harmful effects while maintaining optimal recovery performance.
2Device complexity
If the charge pump uses a fixed clock frequency, then the system complexity is reduced, but the output voltage accuracy deteriorates due to variations in ramp rates across different operating conditions
Solution Approach 1:
The system changes the operational parameters by introducing variable clock frequency control. Instead of using a single fixed frequency, the system adjusts the clock frequency parameter dynamically based on the actual ramp rate measurements. This allows the charge pump to adapt to different operating conditions and maintain accurate output voltage levels across various scenarios.
3Productivity
If the charge pump recovers quickly from reset to operating voltage, then the productivity is improved, but the reliability deteriorates due to read disturbs in non-volatile memory devices
Solution Approach 1:
The system uses feedback control to monitor the ramp rate during the recovery phase and adjusts the clock frequency accordingly. This ensures that the recovery process completes efficiently while maintaining the ramp rate below thresholds that would cause read disturbs in memory devices, thus preserving reliability.
Solution Approach 2:
The charge pump employs dynamic clock frequency adjustment during the recovery phase. The system transitions from static to dynamic operation, where the clock frequency is continuously adapted to achieve the optimal balance between fast recovery and preventing harmful effects on memory devices.
Data Source
AI summary
A method is presented of setting a frequency of a clock for a charge pump system including the clock and a charge pump. This includes setting an initial value for the frequency of the clock and, while operating the charge pump system using the clock running at the initial frequency value, determining the ramp rate of an output voltage for the charge pump during a recovery phase. The frequency of the clock is then adjusted so that the ramp rate of the output voltage for the charge pump during the recovery phase falls in a range not exceeding a predetermined maximum rate. A charge pump system is also described that includes a register having a settable value, where the charge pump clock frequency is responsive to the register value, and count and comparison circuitry is connectable to receive the pump's output voltage and the clock signal and determine from them the number of clock cycles the charge pump uses to recover from a reset value to a predetermined value.