Level Shifter Power Switching for Stable Interface Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional level shifters fail to maintain stable inter-device communication when the power voltage stability of external devices is insufficient, leading to variations in signal waveform amplitude and maximum value over time.
Innovation Solution
A level shifter with a power switch unit, internal and external interface power units, and a selector unit that controls power supply and conduction between interface circuits, ensuring stable communication by adapting to the electrical input-output characteristics of both devices, even with unstable power voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional level shifter is used with unstable power voltage, then the device can interface with external devices, but the signal waveform amplitude and maximum value vary with time
Solution Approach 1:
The patent introduces an external interface power unit as an intermediary power source between the internal interface circuit and the external device interface circuit. This mediator supplies stable power voltage specifically to the interface circuit, isolating it from fluctuations in the internal power supply, thereby maintaining consistent signal waveform characteristics while enabling compatibility with various external devices
2Reliability
If power is continuously supplied to the interface circuit, then stable communication is maintained, but power is wasted when no external device is connected
Solution Approach 1:
The patent employs a power switch unit that dynamically controls the power supply state of the external interface power unit based on detection of external device connection status. When an external device is detected, power is supplied to maintain stable communication; when no device is connected, power supply is stopped to eliminate waste, thus adapting the system's power consumption characteristics to actual operational needs
Data Source
AI summary
A level shifter included in a device includes an external interface power circuit configured to supply a power voltage corresponding to electrical input-output characteristics of an interface circuit of an external device, an internal interface power circuit configured to supply a power voltage corresponding to electrical input-output characteristics of an internal interface circuit in the device, a power switch configured to control power supply to the external interface power unit according to an electrical signal from the external device, and a selector configured to control conduction between the interface circuit of the external device and the internal interface circuit. The selector is configured to transition to an operable state when the external interface power unit is supplied with power.