Boosted Level Shifter Circuit for Near-Threshold Voltage Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing circuit architectures fail to effectively support near-threshold operating voltages with optimized power, performance, and area (PPA) criteria, particularly in voltage level shifting, due to unreliable designs and leakage concerns, especially when input voltages approach sub-threshold levels of transistor devices.
Innovation Solution
The implementation of a level shifter architecture with boost circuitry that includes multiple stages, such as a diode-based latch with feedback assist branches and a boost circuit, enabling voltage shifting across a wide range from ultra-low core voltages to higher input-output voltages with high performance and reduced area, supporting frequencies up to 300 MHz.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing voltage level shifter architectures are used, then the circuit can operate at standard voltage levels, but it fails to reliably support near-threshold operating voltages with optimized power, performance and area
Solution Approach 1:
The level shifter is divided into multiple stages: a first stage for initial voltage level shifting, a second stage for intermediate processing, and a third stage (boost circuit) for final voltage enhancement. This segmentation allows each stage to be optimized for specific voltage ranges, enabling reliable operation from ultra-low core voltages (0.36V) to higher IO voltages (1.98V) while maintaining stability at near-threshold conditions.
Solution Approach 2:
The patent employs dynamic parameter changes including variable transistor sizing across stages, adjustable threshold voltages through body biasing, and configurable boost circuit activation. These parameter adjustments enable the circuit to adapt to different operating conditions, particularly improving reliability at near-threshold voltages while maintaining performance across the full voltage range.
2Ease of operation
If transistor device size is increased to enable turning on at sub-threshold levels, then the transistor can conduct at lower voltages, but the area increases and leakage concerns worsen
Solution Approach 1:
Different transistor sizes and types are used in different stages of the level shifter. The first stage uses transistors optimized for ultra-low voltage operation with larger effective area, while subsequent stages use progressively smaller transistors. This local quality differentiation enables sub-threshold turning on capability where needed without unnecessarily increasing the total area of the entire circuit.
Solution Approach 2:
The circuit employs dynamic transistor sizing techniques where transistor effective area is adjusted based on operating conditions. Body biasing and gate control mechanisms dynamically modify transistor characteristics to enable turning on at sub-threshold levels without requiring permanently large transistor dimensions, thus reducing overall area and leakage.
3Productivity
If existing level shifter architectures are used, then the design is simpler, but the performance is insufficient to meet desired level shifter performance with lesser area and leakage
Solution Approach 1:
The level shifter is divided into multiple stages: a first stage for initial voltage level shifting, a second stage for intermediate processing, and a third stage (boost circuit) for final voltage enhancement. This segmentation allows each stage to be optimized for specific voltage ranges, enabling reliable operation from ultra-low core voltages (0.36V) to higher IO voltages (1.98V) while maintaining stability at near-threshold conditions.
Solution Approach 2:
The multi-stage architecture with boost circuit serves multiple functions: voltage level shifting, voltage boosting, leakage reduction, and performance optimization. This universal design meets desired level shifter performance requirements with lesser area and leakage while supporting a broad voltage range, effectively consolidating multiple functions into a single integrated circuit.
4Use of energy by moving object
If voltage level shifting is performed at near sub-threshold levels, then power consumption is reduced, but the level shifting response becomes slower
Solution Approach 1:
The boost circuit operates periodically to enhance voltage levels during critical phases of operation. By timing the boost circuit activation with the level shifting process, the circuit achieves fast response during voltage transitions while maintaining low power consumption during steady-state near-sub-threshold operation. This periodic action reconciles the trade-off between power savings and response speed.
Solution Approach 2:
The circuit dynamically changes operating parameters including voltage levels and transistor characteristics based on operational requirements. During fast switching events, the boost circuit temporarily increases voltage levels to accelerate response. During normal operation, the circuit operates at near-sub-threshold levels for low power consumption. This dynamic parameter adjustment resolves the contradiction between power efficiency and response speed.
Data Source
AI summary
Various implementations described herein are related to a device having a level shifting circuit that shifts an input voltage in a first domain to an output voltage in a second domain, and also, the level shifting circuit may shift the input voltage to the output voltage based on a first level shifting response. The device may also include a boost circuit that increases the input voltage and provides a boosted input voltage to the level shifting circuit so that the level shifting circuit shifts the input voltage to the output voltage based on the boosted input voltage.