Pulse-Accelerated Level Shifter for Fast Rising Output Transitions
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Solution Overview
Problem
Existing level shifters face challenges in achieving high-speed transitions due to the limitations of pull-up circuit strength, which results in slow low-to-high transitions, while ensuring smooth high-to-low transitions.
Innovation Solution
A level shifter design incorporating an acceleration circuit with pulse generation transistors and current mirrors, controlled by an acceleration controller, accelerates low-to-high transitions without complex logic gates, and includes leakage protection to prevent current leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the pull-up circuit is designed with strong driving capability to achieve immediate low-to-high transition, then the low-to-high transition speed is improved, but the high-to-low transition becomes non-smooth
Solution Approach 1:
The patent employs periodic pulse signals generated by the acceleration controller to periodically activate the acceleration circuit. This periodic action provides temporary current bursts during low-to-high transitions without permanently altering the pull-up circuit's driving capability, thus maintaining smooth high-to-low transitions while accelerating low-to-high transitions.
Solution Approach 2:
The acceleration circuit is activated in advance during the low-to-high transition period to prepare and deliver current before the transition completes. This preliminary action ensures the transition starts immediately without waiting for the pull-up circuit to build up sufficient voltage, while the pull-up circuit remains the primary driver for high-to-low transitions.
2Stability of the object's composition
If the pull-up circuit is designed with weak driving capability to ensure smooth high-to-low transition, then the high-to-low transition smoothness is improved, but the low-to-high transition becomes slow
Solution Approach 1:
The acceleration circuit acts as an intermediary between the input circuit and the output node. It provides additional current support during low-to-high transitions without interfering with the pull-up circuit's normal operation during high-to-low transitions. The acceleration controller mediates when the acceleration circuit should be active, allowing it to supplement the pull-up circuit only when needed.
3Speed
If an acceleration circuit is added to accelerate low-to-high transition, then the low-to-high transition speed is improved, but the device complexity increases
Solution Approach 1:
The acceleration controller serves multiple functions: it generates pulse signals, controls the acceleration circuit timing, and derives control signals from the input signal itself. The acceleration circuit uses standard current mirror transistors that can be integrated with existing process technologies. This multi-functionality reduces the need for additional dedicated components, thereby limiting the increase in device complexity.
4Speed
If pulse generation transistors are used in the acceleration controller, then the acceleration circuit can be enabled in pulse manner for high-speed transition, but the power consumption increases
Solution Approach 1:
The acceleration controller generates periodic pulse signals rather than continuous signals. This allows the acceleration circuit to be activated only during the brief periods when transitions occur, rather than remaining continuously active. The pulse width is limited to the duration needed for the transition, significantly reducing overall power consumption compared to continuous activation.
Solution Approach 2:
The acceleration controller derives its control signals directly from the input signal and its inverted version, making the system self-regulating. When the input signal is stable, no pulses are generated and the acceleration circuit remains off, consuming minimal power. The system automatically activates the acceleration circuit only when transitions are detected, eliminating the need for external control logic and reducing overall system power consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves high-speed transitions with reduced power consumption by utilizing pulse-controlled acceleration circuits and current mirrors, ensuring rapid voltage level changes at the output terminals.
Implementation Method 1
The acceleration circuit includes a first current mirror, which is controlled by the acceleration controller to provide a first acceleration current to the first connection node in the pulse manner
Implementation Method 2
The first series of pulse generation transistors receive first driving signals, which have time differences between them, and thereby the acceleration controller enables the acceleration circuit in a pulse manner
Implementation Method 3
The first delay circuit receives an inverted input signal that is inverted from the input signal, to generate a delayed inverted input signal
Data Source
AI summary
A level shifter is disclosed. The input circuit receives an input signal operating within a first voltage range that is defined by a first voltage level. A pull-up circuit is coupled between a second voltage line and the input circuit. The second voltage line supplies a second voltage level. The second voltage level is higher than the first voltage level. A first connection node between the pull-up circuit and the input circuit serves as an output terminal of the level shifter. An acceleration circuit coupled to the first connection node accelerates the low-to-high transition at the output terminal. The acceleration controller for the acceleration circuit includes a first series of pulse generation transistors driven by first driving signals which have time differences therebetween, so that the acceleration controller enables the acceleration circuit in a pulse manner. The first driving signals are derived from the input signal.