Negative Level Shifter Using a Single Deep Well
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Solution Overview
Problem
Conventional level shifters require separate deep wells for multiple differential amplification stages, leading to a larger circuit size and increased current consumption.
Innovation Solution
A level shifter design that incorporates a differential input stage, breakdown voltage controller, and load stage using NMOS and PMOS transistors within a single deep well, with bias voltages applied to the transistors to control voltage levels without exceeding breakdown voltages, reducing circuit size and current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate deep wells are used for multiple differential amplification stages, then the breakdown voltage levels are maintained, but the circuit size becomes relatively large
Solution Approach 1:
The patent combines multiple differential amplification stages into a single deep well structure. The first and second differential amplification stages share the same deep well, eliminating the need for separate deep wells for each stage. This merging approach reduces the overall circuit area while maintaining the breakdown voltage protection function through shared well isolation.
Solution Approach 2:
The single deep well structure serves multiple functions: it provides breakdown voltage protection for both the first and second differential amplification stages simultaneously, acts as a common isolation structure, and enables compact integration of multiple stages. This multi-functional design resolves the contradiction by making the deep well structure serve universal purposes across different stages.
2Adaptability or versatility
If multiple differential amplification stages are implemented, then the voltage level shifting capability is achieved, but the current consumption increases
Solution Approach 1:
The patent merges the first and second differential amplification stages into a compact configuration within a single deep well. By combining these stages and sharing common structures (such as the deep well isolation and biasing networks), the current consumption is reduced compared to having completely separate implementations, while maintaining the full voltage level shifting capability from first to third voltage levels.
Data Source
AI summary
A level shifter including a differential input stage including first and second transistors having respective first terminals, respective control terminals configured to receive a differential input signal, and respective second terminals connected in common to a first voltage; a breakdown voltage controller including third and fourth transistors having respective first terminals, respective second terminals connected to respective first terminals of the first and second transistors, and respective control terminals configured to receive a bias signal, and a load stage comprising fifth and sixth transistors having respective first terminals connected to respective first terminals of the third and fourth transistors, respective control terminals that are cross coupled, and respective second terminals connected to a second voltage is disclosed. A bias voltage applied to bulks or bodies of the first through the fourth transistors equals or substantially equals the first voltage.