Latch-Controlled Voltage Level Shifter for Fast Low-Power Transfer
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Solution Overview
Problem
Existing level shifters face a compromise between low current consumption and high transfer speed, as reducing current consumption leads to longer transfer times and vice versa, making it difficult to achieve both low power consumption and fast signal transfer in digital electronic circuits.
Innovation Solution
The proposed level shifter design incorporates a latch structure with cross-coupled CMOS transistors and controller modules that control switch elements during transition and stability periods, allowing for short transition times with minimal current consumption by using biased and switch transistors in parallel with resistive elements to limit drain-source current during short transition periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional level shifter design is used, then current consumption is reduced, but transfer delay increases
Solution Approach 1:
The circuit dynamically switches between different operational modes using control signals. During transition periods, the circuit activates fast switching paths with lower resistance to reduce transfer delay. During stability periods, it switches to high-impedance paths to minimize current consumption. This dynamic adaptation allows the circuit to optimize both speed and power consumption at different times.
Solution Approach 2:
The level shifter operates in periodic cycles consisting of transition periods and stability periods. During transition periods, the circuit prioritizes fast signal transfer by activating low-resistance paths. During stability periods, it prioritizes low current consumption by deactivating these paths. This periodic switching between operational states resolves the contradiction between speed and power consumption.
2Speed
If conventional level shifter design is used, then transfer speed is improved, but current consumption increases
Solution Approach 1:
The circuit employs dynamic control mechanisms that adjust the operational state of switching elements based on signal transition requirements. Fast switching elements are activated only during transition periods when speed is critical, while remaining in high-impedance states during stability periods to minimize current draw. This dynamic behavior enables the circuit to achieve fast transfer speeds only when necessary.
Solution Approach 2:
The level shifter uses periodic control signals to activate fast switching paths only during transition periods. During stability periods, these paths are deactivated to reduce current consumption. This periodic activation strategy allows the circuit to maintain fast transfer capabilities while minimizing overall power consumption throughout the operating cycle.
3Loss of time
If fast transition is achieved, then transfer delay is reduced, but current consumption increases
Solution Approach 1:
The circuit dynamically adjusts the conductivity of switching elements during transition periods to enable fast signal propagation. Control signals temporarily reduce the on-resistance of switching elements M4 and M5 during transitions, achieving fast transition times. After transitions complete, the circuit returns to high-impedance states to minimize current consumption during stability periods.
Solution Approach 2:
Fast switching paths are activated periodically only during transition periods when rapid signal transfer is required. During stability periods, these paths remain inactive with high impedance to minimize current consumption. This periodic activation pattern enables the circuit to achieve fast transition times without continuously consuming high current.
4Use of energy by moving object
If low current consumption is achieved, then power consumption is reduced, but transfer speed decreases
Solution Approach 1:
The circuit dynamically switches between power-saving mode and high-speed mode based on operational requirements. During stability periods, the circuit maintains high-impedance states to minimize current consumption and power dissipation. During transition periods, control signals activate low-resistance paths to enable fast signal transfer, temporarily increasing current consumption only when speed is required.
Solution Approach 2:
The level shifter operates in periodic cycles where power-saving mode dominates during stability periods, and high-speed mode is activated only during transition periods. This periodic switching ensures that the circuit consumes minimal power overall while still providing fast transfer capability when needed, resolving the contradiction between power consumption and transfer speed.
Data Source
AI summary
A level shifter includes a latch supplied at a first voltage VDD1. First and second switches are connected in series with first and second latches and are cross-coupled to maintain the state of the latches during a stability period. A controller responds to a change of state of an input signal at a voltage different from the first voltage at an end of the stability period to deactivate both the first and second switches, to cause third and fourth switches to deactivate both the first and second latches during a transition period, and subsequently to change the state of the latch and maintain the changed state during the subsequent stability period. This avoids undesirable compromise between current consumption and transfer delay, as in a conventional level shifter.