Bias-Assisted Level Shifter for Faster High-Frequency Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional level shifters have low operating speeds due to high threshold voltage and low input voltage amplitude, making them unsuitable for high-frequency operations.
Innovation Solution
A level shifter design incorporating a bias voltage providing circuit, a level shifting circuit with high and low level shifting units, and an output switching circuit using different types of switch elements to enable partial cut-off states, enhancing response speed by utilizing core devices and IO devices effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional level shifter design is used, then device simplicity is maintained, but response speed is slow due to high threshold voltage and low input voltage amplitude
Solution Approach 1:
The level shifter is divided into multiple independent units: high level shifting unit, low level shifting unit, bias voltage providing units, and output switching units. Each unit operates independently with its own bias voltage, allowing parallel operation and faster response without increasing overall system complexity.
Solution Approach 2:
Bias voltages are provided in advance to the shifting units before signal transitions occur. This preliminary biasing ensures that the switching elements are pre-positioned in optimal states, enabling faster response when voltage level changes are needed, eliminating the delay caused by threshold voltage limitations.
2Productivity
If conventional level shifter design is used, then device simplicity is maintained, but operating frequency is limited due to slow response speed
Solution Approach 1:
The patent changes the voltage parameters by introducing multiple bias voltages (first bias voltage, second bias voltage, third bias voltage) at different levels. This parameter modification allows the switching elements to operate in optimized regions, enabling high-frequency operation by overcoming the limitations of conventional single-voltage-level designs.
Solution Approach 2:
The level shifter employs dynamic switching between different voltage levels using controlled switching elements. The circuit can dynamically adjust its operating state based on input signals, transitioning between high level, low level, and intermediate states, which enables adaptation to high-frequency signal variations.
3Speed
If bias voltage is applied to maintain partial cut-off state, then response speed increases, but device complexity increases due to additional bias voltage providing circuit
Solution Approach 1:
The bias voltage providing circuit serves multiple functions: it provides bias voltages to different shifting units, establishes partial cut-off states for switching elements, and enables high-frequency operation. This multi-functional design reduces the need for separate circuits for each function, thereby limiting the increase in overall device complexity.
Data Source
AI summary
A level shift includes a bias voltage providing circuit, a level shifting circuit and an output switching circuit. The level shifting circuit includes a high level shifting unit and a low level shifting unit. When the high level shifting unit is in a cut-off state, the high level shifting unit further receives a first bias voltage such that the high level shifting unit is in a partially cut-off state, accordingly increasing a response speed of the high level shifting unit. When the low level shifting unit is in a cut-off state, the low level shifting unit further receives a second bias voltage such that the low level shifting unit is in a partially cut-off state, accordingly increasing a response speed of the low level shifting unit. The level shifter of the present application provides a higher response speed.