OR Gate Level Shifter Circuit for Mixed-Voltage I/O

Solution Overview

Problem

High-density storage devices face challenges in reducing PCB footprint and component costs due to the need for voltage level-shifting ICs to accommodate different I/O voltages, especially with the trend towards lower voltage I/Os in SoC and SSDs, while legacy devices with higher voltage IOs are still in use.

Innovation Solution

A circuit design that combines the functionality of an OR gate and a level shifter using two N-channel MOSFETs and resistors, allowing for a single power supply and reducing the number of components, thereby minimizing space and cost, while supporting both lower and higher voltage I/Os.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate OR gate IC and level shifter IC are used, then voltage level shifting function is achieved, but PCB footprint and component cost increase

Engineering Contradiction:

Improvevoltage level shifting functionVSAvoidPCB footprint

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines the OR gate logic function and the voltage level shifting function into a single integrated circuit. The OR gate IC includes internal level shifting circuitry that automatically shifts the output voltage level based on the difference between supply voltage VCC and input voltage Vin, eliminating the need for a separate level shifter IC and reducing PCB footprint.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The OR gate IC is designed to perform multiple functions: it performs the logical OR operation on input signals while simultaneously acting as a voltage level shifter. The circuit can handle different input voltage levels (Vin) and supply voltage levels (VCC), providing both logic functionality and voltage adaptation in one component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If separate OR gate IC and level shifter IC are used, then voltage level shifting function is achieved, but component cost increases

Engineering Contradiction:

Improvevoltage level shifting functionVSAvoidcomponent cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent combines the OR gate logic function and the voltage level shifting function into a single integrated circuit. The OR gate IC includes internal level shifting circuitry that automatically shifts the output voltage level based on the difference between supply voltage VCC and input voltage Vin, eliminating the need for a separate level shifter IC and reducing PCB footprint.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The OR gate IC is designed to perform multiple functions: it performs the logical OR operation on input signals while simultaneously acting as a voltage level shifter. The circuit can handle different input voltage levels (Vin) and supply voltage levels (VCC), providing both logic functionality and voltage adaptation in one component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If traditional OR gate with lower output voltage is used, then MCU I/O specifications are met, but voltage level flexibility is reduced

Engineering Contradiction:

ImproveMCU I/O specification complianceVSAvoidvoltage level flexibility

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent utilizes variable voltage parameters VCC and Vin to dynamically adjust the output voltage level. The level shifting function is achieved by exploiting the voltage difference between VCC and Vin, allowing the circuit to adapt to different voltage requirements while maintaining compliance with MCU I/O specifications.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11171635B2Circuits and methods of operating the circuits

Publication Date: 2021.11.09 SK HYNIX INC

AI summary

Circuits integrating OR logic and level shifting functionality and methods of operating the same are configured to accommodate different applications. One such circuit comprises first and second transistors coupled in parallel defining first and second nodes, the first transistor being responsive to a first input signal and the second transistor being responsive to a second input signal; a first resistor coupled between a power supply terminal of the circuit and the first node; and a second resistor coupled between the second node and a ground terminal of the circuit. The circuit generates an output signal having a voltage level that is lower than a voltage level of each of the first and second input signals.