Startup-Initialized Level Shifter for Glitch-Free Voltage Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Level shifters face challenges in initializing nets or nodes at startup, leading to glitches and overvoltage conditions that can damage components due to incompatibility between different voltage domains.
Innovation Solution
A driver circuit is used to set an initial state for the level shifter, utilizing AC coupling capacitors and DC level shifters to mitigate incorrect initialization and prevent glitches by converting signals between voltage domains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a level shifter is used to convert signals between voltage domains, then compatibility between components operating at different voltage levels is improved, but incorrect initialization of nets or nodes at startup can occur, leading to glitches and overvoltage conditions
Solution Approach 1:
The patent applies preliminary action by initializing the level shifter circuit before normal operation begins. Specifically, the circuit uses startup circuits that set the initial state of internal nodes and transistors before signal conversion starts, ensuring that the circuit is in a known good state and preventing incorrect initialization, glitches, and overvoltage conditions during startup
2Adaptability or versatility
If traditional level shifter circuits are used, then voltage domain conversion is achieved, but protection against overvoltage damage is insufficient
Solution Approach 1:
The patent applies beforehand cushioning by incorporating protection circuits that prevent overvoltage damage before it can occur. The circuit includes clamping diodes, voltage limiting circuits, or other protective elements that are pre-configured to clamp or limit voltages to safe levels, cushioning the sensitive transistors and nodes from overvoltage stress during abnormal conditions or startup transients
Data Source
AI summary
In some examples, an apparatus includes a first level shifter circuit having first, second, third, and fourth inputs. The apparatus also includes a second level shifter circuit having first and second inputs, and first and second outputs. The first input of the second level shifter circuit is coupled to the first input of the first level shifter circuit. The second input of the second level shifter circuit is coupled to the second input of the first level shifter circuit. The first output of the second level shifter circuit is coupled to the third input of the first level shifter circuit. The second output of the second level shifter circuit coupled to the fourth input of the first level shifter circuit.