Charge Pump Regulation Circuit for Nonvolatile Memory
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Solution Overview
Problem
Existing charge pump regulation schemes for non-volatile memory devices do not effectively track variations in parasitic diode breakdown voltage due to process and temperature variations, leading to potential breakdown and damage during program and erase operations.
Innovation Solution
A charge pump and regulation circuit that includes a comparator and current mirrors to monitor and control the charge pump output voltage, ensuring it does not exceed the safe reverse bias threshold by comparing voltages and adjusting the clock signals to prevent diode breakdown, using a diode formed in the same process as the memory transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rail voltage limits are defined for parasitic PN junctions to prevent breakdown, then reliability is improved, but area cost and production cost increase
Solution Approach 1:
The patent implements a feedback mechanism where a comparator continuously monitors the charge pump output voltage and compares it against a reference voltage. When the output voltage approaches the breakdown threshold of parasitic diodes, the comparator triggers a control signal to stop or reduce charge pump operation, preventing diode breakdown without requiring oversized voltage rails
Solution Approach 2:
The patent dynamically adjusts the charge pump output voltage based on real-time conditions by monitoring against a reference voltage. Instead of using fixed high voltage rails, the system changes the voltage parameter adaptively, stopping charge pump operation when the monitored voltage reaches a safe threshold, thus preventing breakdown while optimizing area usage
2Productivity
If charge pump output voltage is increased to improve program and erase efficiency, then productivity is improved, but risk of parasitic diode breakdown increases
Solution Approach 1:
The comparator provides continuous feedback monitoring of the charge pump output voltage. When the voltage reaches a threshold close to the parasitic diode breakdown voltage, the comparator generates a control signal that stops or modulates the charge pump operation, allowing high voltage operation for efficiency while preventing breakdown through real-time feedback control
Solution Approach 2:
The system dynamically adjusts the charge pump operation based on real-time voltage conditions. The charge pump can operate at high voltages to maximize program and erase efficiency, but the system dynamically stops or reduces operation when the monitored voltage approaches the breakdown threshold, enabling adaptive optimization of both efficiency and safety
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution prevents diode breakdown by maintaining a safe reverse bias across parasitic diodes, reducing the risk of damage and allowing for efficient program and erase operations while reducing production costs and area requirements.
Implementation Method 1
A comparator has an inverting input coupled to the second node and a non-inverting input coupled to a third node, the comparator being configured to cause generation of the at least one charge pump control signal
Implementation Method 2
A current sink is configured to sink a first current from the second node
Implementation Method 3
a current source is configured to source a second current to the third node, the second current having a same magnitude as the first current
Implementation Method 4
A diode has a cathode coupled to the first node and an anode coupled to a second node
Data Source
AI summary
A charge pump circuit generates a charge pump output signal at a first node and is enabled by a charge pump control signal. A diode has first and second terminals coupled to first and second nodes. A comparator has an inverting input coupled to the second node and a non-inverting input coupled to a third node, and causes generation of the charge pump control signal. A first current mirror produces a first current at the second node, and a second current mirror produces a second current (equal in magnitude to the first current) at the third node. The first terminal and second terminals may be a cathode and an anode. The first current mirror may be a current sink sinking a first current from the second node. The second current mirror may be current source sourcing a second current (equal in magnitude to the first current) to the third node.