Internal Voltage Generation Circuit for Peak Current Suppression
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Solution Overview
Problem
Semiconductor memory devices face challenges in stabilizing internal voltage generation during power-up, leading to peak current spikes due to abrupt voltage increases, which can cause increased current consumption and instability.
Innovation Solution
An internal voltage generation circuit that buffers and integrates a reference voltage, using a divider and selector to control the voltage rise with a constant slope, and a second voltage generator that receives or blocks external power based on feedback voltage comparisons, stabilizing the operation and reducing peak current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the internal voltage is generated by directly applying external power voltage during power-up, then the voltage generation speed is fast, but peak current spikes occur due to abrupt voltage increases
Solution Approach 1:
The circuit performs preliminary actions by buffering the reference voltage before integration and using enable signals to control the timing of voltage generation. The first voltage generator buffers the reference voltage from a first time point to a second time point, and the second voltage generator is enabled only after the initial voltage reaches a threshold, preventing peak current while maintaining efficient voltage generation.
Solution Approach 2:
The patent introduces intermediary elements including the first voltage generator that buffers reference voltage, the second voltage generator that integrates the buffered voltage, and enable signals that mediate between the power supply and voltage generation circuits. These intermediaries control the rate of voltage change, suppressing peak current while maintaining generation speed.
2Loss of time
If the voltage rises rapidly during power-up, then the power-up time is reduced, but current consumption increases due to peak current generation
Solution Approach 1:
The circuit prepares in advance by buffering the reference voltage during a predetermined period before actual voltage generation begins. This preliminary buffering action allows the subsequent integration phase to proceed efficiently without causing peak current, thus reducing overall power-up time while controlling current consumption.
Solution Approach 2:
The voltage generation process is divided into periodic phases: a buffering period where reference voltage is prepared, a transition period where integration begins, and a stable generation period. This periodic structure optimizes both speed and energy efficiency by controlling when current is drawn and how voltage rises.
3Reliability
If all circuits are initialized by a power-up reset signal, then the system stability is improved, but the complexity of the initialization control increases
Solution Approach 1:
The initialization control is segmented into multiple independent parts: a power-up reset signal for overall system initialization, enable signals for controlling specific voltage generation circuits, and threshold-based control for the second voltage generator. This segmentation maintains system stability while reducing the complexity of any single control mechanism.
Solution Approach 2:
The circuit uses feedback mechanisms where the second voltage generator monitors its own output voltage and compares it against a threshold voltage. When the initial voltage reaches the threshold, the generator automatically stops integrating, providing self-controlled initialization that improves reliability without requiring complex external control logic.
Data Source
AI summary
An internal voltage generation circuit comprising: a first voltage generator buffers a first reference voltage from a first to a second time point and integrates the first reference voltage after the second time point to generate a first initial voltage, a divider outputs a second initial voltage by dividing the first initial voltage from the first to the second time point and to outputs the first initial voltage as the second initial voltage after the second time point, a selector selects and output the second initial voltage or a second reference voltage based on a comparison of level of a feedback voltage and the second reference voltage, and a second voltage generator generates an internal voltage depending on a result of comparing levels of an output voltage of the selector and the feedback voltage, and to generates the feedback voltage by dividing the internal voltage.