Internal Voltage Generation Circuit for Semiconductor Memory
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Solution Overview
Problem
Semiconductor memory devices face challenges in accurately detecting memory cells and data transmission paths with varying data retention characteristics due to fluctuations in internal voltage, leading to incorrect identification of defective cells and paths, which affects yield and reliability.
Innovation Solution
An internal voltage generation circuit that includes a voltage generation circuit and a voltage control circuit, utilizing pull-up and pull-down current load circuits to maintain the output voltage within specific limits, ensuring accurate detection and correction of voltage variations, thereby improving data retention and detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage generation circuit generates power supply voltage without precise control, then circuit complexity is reduced, but measurement precision of data retention characteristics deteriorates
Solution Approach 1:
The voltage generation circuit incorporates a feedback mechanism where the generated power supply voltage is fed back to a voltage detection circuit. The detection circuit compares the actual voltage against reference values and generates control signals to adjust the voltage generation, ensuring precise control of voltage within specified ranges for accurate data retention measurement.
Solution Approach 2:
The circuit dynamically adjusts the power supply voltage parameter based on detection results. The voltage generation circuit can modify the output voltage level in response to feedback from the voltage detection circuit, allowing precise control of the voltage parameter to match specific test requirements for data retention characteristics.
2Reliability
If voltage fluctuations are allowed in internal voltage generation, then device complexity is reduced, but reliability of memory cell detection deteriorates
Solution Approach 1:
A feedback control system is implemented where the power supply voltage is continuously monitored by a voltage detection circuit and compared against reference values. The detection circuit generates control signals based on deviations from target voltage levels, and the voltage generation circuit adjusts accordingly, ensuring stable and reliable voltage for accurate memory cell detection.
Solution Approach 2:
The voltage generation circuit performs preliminary voltage adjustment and stabilization before memory cell detection operations begin. The feedback mechanism ensures that the voltage reaches and maintains the required stable level in advance, preventing voltage fluctuations from affecting detection reliability during actual memory cell testing.
3Manufacturing precision
If voltage is not controlled within specified limits, then ease of operation is improved, but manufacturing precision of detection results deteriorates
Solution Approach 1:
The voltage control system operates automatically through feedback from the voltage detection circuit to the voltage generation circuit. The system self-regulates to maintain voltage within specified limits without requiring manual intervention, achieving precise detection results while maintaining ease of operation through automated control.
Solution Approach 2:
The voltage generation and control system is designed to self-regulate and self-correct voltage deviations automatically. The feedback mechanism enables the circuit to monitor and adjust its own output, eliminating the need for external manual voltage control while ensuring precise detection results through consistent voltage maintenance.
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
The solution effectively maintains the output voltage within predetermined limits, enhancing the detection of defective memory cells and data transmission paths, improving yield and reliability by preventing misidentification and ensuring data integrity.
Implementation Method 1
a first current load circuit that changes the voltage of the output node so as to pull down the voltage of the output node
Implementation Method 2
a second current load circuit that changes the voltage of the output node so as to pull up the voltage of the output node
Data Source
AI summary
An internal voltage generation circuit includes a vblh voltage generation circuit that generates a voltage vblh that is supplied as a high-voltage power supply of a sense amplifier, and a voltage distribution control circuit that has a first current source that pulls down an output node and a second current source that pulls up the output node. The output node is pulled down by the first current source operating, and the voltage thereof is maintained at a voltage that corresponds to a lower limit of a detection voltage value. The output node is pulled up by the second current source operating, and the voltage thereof is maintained at a voltage that corresponds to an upper limit of the detection voltage value.