Internal Voltage Generator Leakage Current Control
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Solution Overview
Problem
Conventional semiconductor memory devices face increased power consumption and size due to leakage currents caused by resistive shorts between word lines and bit lines, which are difficult to manage with fixed bleeder circuits.
Innovation Solution
An internal voltage generator with a voltage drop unit and control unit that adjusts the bit line precharge voltage in response to test mode signals and leakage current measurements, reducing power consumption and chip size by varying the voltage drop amount based on detected leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional bleeder circuit with a fixed transistor is used to reduce leakage current, then power consumption is reduced, but the device complexity increases and chip size increases due to additional wires
Solution Approach 1:
The patent combines the bleeder circuit functionality with the existing bit line precharge voltage generation unit by sharing the precharge voltage wire. The bleeder transistor is integrated into the precharge circuit structure, eliminating the need for separate wires and reducing overall circuit complexity while maintaining leakage current reduction capability
Solution Approach 2:
The bit line precharge voltage generation unit is designed to serve dual purposes: normal precharge operation and leakage current suppression. The same voltage generation circuit and wire are used for both functions, eliminating redundant components and reducing chip size
2Loss of energy
If a conventional bleeder circuit with a fixed transistor is used, then leakage current is reduced, but the device cannot adapt to variable leakage conditions
Solution Approach 1:
The patent introduces dynamic control of the bleeder transistor through a control signal that adjusts the transistor's conductivity based on detected leakage current levels. This allows the circuit to adapt to variable leakage conditions by dynamically modifying the bleeder transistor's resistance, ensuring optimal leakage suppression across different operating conditions
Solution Approach 2:
The circuit incorporates a feedback mechanism where leakage current is detected and used to control the bleeder transistor's operation. The control signal is generated based on the detected leakage current level, creating a closed-loop system that automatically adjusts the bleeder transistor to maintain optimal leakage suppression
3Loss of energy
If the bit line precharge voltage is always supplied through a bleeder transistor, then leakage current is reduced, but power consumption increases due to unnecessary current flow
Solution Approach 1:
The patent implements periodic or conditional activation of the bleeder transistor based on operational mode signals. The bleeder transistor is activated only when needed (e.g., during standby mode or when leakage is detected) and deactivated during active operation, reducing unnecessary power consumption while maintaining leakage suppression capability when required
Solution Approach 2:
The circuit automatically determines when the bleeder transistor should be activated based on internal conditions such as operational mode and detected leakage current. The control logic self-adjusts the bleeder transistor operation without external intervention, optimizing the balance between leakage suppression and power consumption
Data Source
AI summary
An internal voltage generation device includes a plurality of output nodes; a bit line precharge voltage generation unit for generating a bit line precharge voltage; a first voltage drop unit for transferring the bit line precharge voltage to a first output node after decreasing the bit line precharge voltage by a first voltage drop amount in response to a test mode signal; and a second voltage drop unit for transferring the bit line precharge voltage to a second output node after decreasing the bit line precharge voltage by a second voltage drop amount in response to the test mode signal, wherein the second voltage drop amount is greater than the first voltage drop amount.