Boosted High-Speed Level Shifter With Extended Gate-Drive Swing

Solution Overview

Problem

Existing level shifters face inefficiencies in switching voltage levels due to leakage periods during signal transitions, particularly due to the competition between pull-up and pull-down transistors, which affects operational speed and energy efficiency.

Innovation Solution

A boosted high-speed level shifter design that includes a driver circuit to generate a drive signal with a voltage swing greater than the input signal, enhancing the current sourcing capability of pull-up transistors and reducing parasitic capacitance, thereby minimizing leakage periods and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the pull-up transistor is designed with higher current sourcing capability to reduce leakage period, then the operational speed is improved, but the transistor size increases leading to increased parasitic capacitance

Engineering Contradiction:

Improveoperational speedVSAvoidparasitic capacitance

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

A driver circuit is introduced as an intermediary component between the input signal and the pull-up transistor. This driver circuit generates a boosted drive signal with larger voltage swing, which enables the pull-up transistor to achieve high current sourcing capability without requiring a large transistor size, thus reducing parasitic capacitance while maintaining fast operational speed.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The drive signal voltage swing is changed from the standard input signal range to an extended range with larger amplitude. This parameter change allows the pull-up transistor to operate in a regime where it can source high current quickly (reducing leakage period) while the transistor itself can remain small (reducing parasitic capacitance), because the enhanced voltage swing compensates for the smaller device size.

Inventive Principle:

Principle #35Parameter changes

2Duration of action of moving object

If the pull-up transistor size is increased to reduce leakage period duration, then the switching speed is improved, but the device area increases

Engineering Contradiction:

Improveleakage period durationVSAvoiddevice area

Core Design Contradiction:

Duration of action of moving objectVSArea of stationary object

Solution Approach 1:

The driver circuit serves as a mediator that decouples the relationship between transistor size and current sourcing capability. By providing an enhanced drive signal, it allows a small pull-up transistor to achieve the same effective current drive as a larger transistor would provide with standard signaling, thereby reducing both leakage period duration and device area.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The driver circuit provides an excessive or enhanced voltage swing beyond what is minimally required for standard logic operation. This excessive action (larger voltage swing) compensates for the reduced transistor size, enabling fast switching and short leakage periods while maintaining a compact device area.

Inventive Principle:

Principle #16Partial or excessive action

3Device complexity

If a standard drive signal is used without boosting, then the device complexity is reduced, but the current sourcing capability is insufficient leading to longer leakage periods

Engineering Contradiction:

Improvedevice complexityVSAvoidleakage period duration

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

A driver circuit is introduced as an intermediary component between the input signal and the pull-up transistor. This driver circuit generates a boosted drive signal with larger voltage swing, which enables the pull-up transistor to achieve high current sourcing capability without requiring a large transistor size, thus reducing parasitic capacitance while maintaining fast operational speed.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The drive signal voltage swing is changed from the standard input signal range to an extended range with larger amplitude. This parameter change allows the pull-up transistor to operate in a regime where it can source high current quickly (reducing leakage period) while the transistor itself can remain small (reducing parasitic capacitance), because the enhanced voltage swing compensates for the smaller device size.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10396795B1Boosted high-speed level shifter

Publication Date: 2019.08.27 MICRON TECHNOLOGY INC

AI summary

Methods, systems, and devices for shifting voltage levels of electrical signals and more specifically for boosted high-speed level shifting are described. A boosted level shifter may include a driver circuit that generates a drive signal having a greater voltage swing than an input signal, and the drive signal may drive the gate of a pull-up transistor within the boosted level shifter. The lower bound of the drive signal may in some cases be a negative voltage. Driving the pull-up transistor with a drive signal having a greater voltage swing than the input signal may improve the operational speed and current-sourcing capability of the pull-up transistor, which may provide speed and efficiency benefits.