Three Rail Level Shifter Circuit for Voltage Domain Communication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuits face challenges in efficiently communicating data between different voltage domains due to the need for level shifting, which often requires complex modifications and increased costs.
Innovation Solution
A three-rail level shifter circuit that generates upper, mid, and lower voltage rails using cross-coupled devices and capacitors, allowing for flexible voltage programming and operation across various integrated circuits without redesign, functioning as a pre-driver in transmitter circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional level shifting methods are used to communicate data between different voltage domains, then data transmission between voltage domains is achieved, but circuit complexity increases and manufacturing costs increase
Solution Approach 1:
The level shifter circuit is designed to operate across multiple voltage domains (first voltage domain with VDD1/VSS1 and second voltage domain with VDD2/VSS2) using a unified circuit architecture. The circuit can be programmed to support different voltage configurations without requiring redesign, making it universally applicable to various integrated circuit applications with different voltage requirements.
Solution Approach 2:
The level shifter uses programmable voltage references and controllable switches to dynamically adjust its operating voltage parameters. By changing the voltage parameters (VDD1, VSS1, VDD2, VSS2) through programming rather than hardware modification, the circuit adapts to different voltage domains while maintaining the same physical circuit structure, thereby reducing complexity.
2Reliability
If traditional level shifting methods are used to communicate data between different voltage domains, then data transmission between voltage domains is achieved, but manufacturing costs increase
Solution Approach 1:
A single level shifter circuit design can be manufactured and programmed to support multiple voltage domain configurations. This universal design reduces manufacturing costs by eliminating the need to create and stock multiple specialized level shifter variants for different voltage combinations, as one programmable circuit can serve all configurations.
Solution Approach 2:
By implementing voltage domain adaptation through software programming rather than hardware customization, the same manufactured circuit can be configured for different applications. This parameter-based configuration approach reduces manufacturing costs by standardizing the production process while maintaining flexibility for different voltage requirements.
3Use of energy by moving object
If voltage domains are separated to save power in most modules, then power consumption is reduced, but communication between different voltage domains becomes more difficult
Solution Approach 1:
The level shifter acts as an intermediary circuit between the low-voltage domain (where most modules operate to save power) and the high-voltage domain (where certain modules require higher voltage). This intermediary enables seamless communication between the separated voltage domains, making the power optimization strategy practical by solving the communication barrier it creates.
Solution Approach 2:
The level shifter dynamically adjusts its voltage parameters to match the source and destination voltage domains, enabling flexible communication between different voltage levels. This parameter adaptation allows modules operating at different voltages (for power savings) to communicate efficiently without requiring all modules to operate at the same voltage level.
Data Source
AI summary
A level shifter generates at least three separate voltage rails. The level shifter features two cross-coupled devices coupled together in parallel by a capacitor. A first stage includes a PMOS cross-coupled device in series with a PMOS cascode circuit that generates an upper voltage rail. A second stage includes a NMOS cross-coupled device in series with a NMOS cascode circuit that generates a lower rail. A third stage includes the PMOS cascode circuit and the NMOS cascode circuit that together are configured to generate a third voltage rail.