Multi-Converter Rail-to-Rail Voltage Detection With Low Chip Area
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Solution Overview
Problem
Existing on-chip voltage measurement solutions suffer from significant rail-to-rail nonlinearities and require substantial semiconductor chip area, making them unsuitable for distributed on-chip applications.
Innovation Solution
Implementing a rail-to-rail voltage detector with multiple voltage converters, including NMOS and PMOS V2I converters, to achieve accurate voltage measurement with minimal area consumption, using a time-based analog-to-digital conversion method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If analog components such as constant transconductance stages or analog comparators are added to improve linearity, then measurement precision is improved, but device complexity and chip area increase significantly
Solution Approach 1:
The voltage detection range is segmented into multiple intervals, with each interval handled by a dedicated V2I converter optimized for that range. This segmentation allows each converter to operate linearly within its specific voltage range, achieving rail-to-rail coverage without requiring complex analog components across the entire range.
Solution Approach 2:
The system dynamically switches between different V2I converters based on the input voltage level. A voltage detector identifies which converter should be active for the current voltage condition, and the system transitions between converters as needed. This dynamic adaptation enables linear operation across the full voltage range while maintaining simplicity in each individual converter design.
2Measurement precision
If multiple V2I converters are used to achieve rail-to-rail coverage, then measurement precision is improved, but device complexity increases
Solution Approach 1:
Each V2I converter is designed to be universally applicable across the full voltage range through calibration, but in practice, each converter is optimized for a specific voltage interval. The calibration process adjusts the transfer characteristics of each converter so that it accurately measures voltages within its designated range, allowing multiple simple converters to replace what would otherwise require one complex converter.
Solution Approach 2:
A voltage detector provides feedback about the current input voltage level to the system, enabling the selection of the appropriate V2I converter. This feedback mechanism ensures that the correct converter is activated for the current voltage condition, maintaining measurement accuracy while keeping each individual converter simple and specialized.
3Area of stationary object
If time-based analog-to-digital conversion is used, then chip area is reduced, but measurement precision may be compromised
Solution Approach 1:
The patent replaces traditional mechanical/analog voltage measurement approaches with a time-based digital conversion method. Instead of using complex analog components, the system uses time-based measurement techniques combined with multiple simple V2I converters to achieve accurate voltage measurement across the full rail-to-rail range, significantly reducing the required chip area.
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 solution provides accurate rail-to-rail voltage measurement with reduced chip area, enabling efficient parallel testing and validation of on-chip voltages without significant area impact.
Implementation Method 1
a voltage to current converter configured to convert the selected voltage into an output current
Implementation Method 2
a converter configured to convert the output current into a measured value
Data Source
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AI summary
A voltage detector for measuring a voltage between voltage rails including first and second voltage to current (V2I) converters, a current converter, and a controller. The controller enables the first V2I converter when a selected voltage is between the first voltage rail and an intermediate voltage and enables the second V2I converter when the selected voltage is between the intermediate voltage and the second voltage rail. Each V2I converter converts the selected voltage into an output current when enabled. The current converter converts the output current into a measured value and the controller converts the measured value into an output voltage. The controller may enable either V2I converter and select a reference voltage for determining a reference value, then select an input voltage for determining an input value using the enabled V2I converter, and then compare the reference and input values for determining which V2I converter provides a correct result.