Comparator-Based Supply Voltage Measurement With Adaptive References
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to accurately measure internal supply voltages in integrated circuits, which experience voltage drops due to process and temperature variations, affecting the operation of circuit blocks and requiring compensation to ensure consistent voltage levels across different dies and temperatures.
Innovation Solution
A circuit comprising a comparator, resistor divider, multiplexer, and control circuit measures internal supply voltages by comparing them to reference voltages, using a band gap reference voltage generator to maintain constant ratios of resistors, and a programmable current source to adjust for voltage offsets, allowing for precise determination of internal supply voltages despite variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If internal supply voltage is measured directly, then measurement simplicity is improved, but measurement precision deteriorates due to voltage drops from process and temperature variations
Solution Approach 1:
The patent introduces a comparator as an intermediary device that indirectly measures the internal supply voltage by comparing it against a reference voltage. Instead of directly measuring the variable internal voltage, the comparator determines whether the internal voltage is higher or lower than a known reference, thereby achieving accurate measurement without direct contact with the unstable voltage source.
Solution Approach 2:
The patent creates a reference voltage that copies or replicates the characteristics of the desired internal supply voltage level. By generating a reference voltage through a resistor divider and comparing it with the internal voltage, the system effectively creates a stable reference copy that can be used for accurate measurement despite process and temperature variations.
2Device complexity
If a fixed reference voltage is used for comparison, then device complexity is reduced, but adaptability deteriorates as it cannot compensate for voltage drops across different dies and temperatures
Solution Approach 1:
The patent implements a dynamic reference voltage system where the reference voltage can be adjusted based on the internal supply voltage level. The control circuit dynamically selects different reference voltages from the resistor divider network, allowing the system to adapt to different operating conditions and compensate for voltage drops across process and temperature variations while maintaining manageable complexity through automated control.
Solution Approach 2:
The patent changes the reference voltage parameter dynamically by selecting different voltage levels from a resistor divider network. The control circuit modifies the reference voltage parameter based on comparisons with the internal supply voltage, enabling the system to adapt to different dies and temperature conditions without requiring a completely complex redesign of the reference voltage generation system.
3Measurement precision
If multiple reference voltages are generated through a resistor divider, then measurement precision is improved, but device complexity increases due to additional components and control logic
Solution Approach 1:
The patent segments the reference voltage generation into discrete levels using a resistor divider network. Instead of using a single complex variable reference voltage source, the system divides the reference voltage into multiple fixed levels that can be selectively accessed. This segmentation simplifies the control logic while providing sufficient measurement precision through the discrete voltage steps.
Solution Approach 2:
The resistor divider network serves multiple functions: it generates multiple reference voltage levels, provides a scalable structure for different measurement ranges, and enables both coarse and fine measurement through selective activation. This multi-functionality reduces the need for separate circuits for different measurement purposes, thereby managing complexity while improving precision.
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
This solution enables accurate measurement and compensation of internal supply voltages, ensuring consistent operation of circuit blocks across different integrated circuit dies and temperatures, thereby addressing the issue of voltage drops and variations.
Implementation Method 1
The comparator compares an internal supply voltage of the circuit to a selected reference voltage
Implementation Method 2
The resistor divider generates reference voltages
Implementation Method 3
The programmable current source supplies charge for the reference voltage
Data Source
AI summary
A circuit can include a comparator, a resistor divider, a control circuit, and a multiplexer. The comparator compares an internal supply voltage of the circuit to a selected reference voltage. The resistor divider generates reference voltages. The control circuit receives an output signal of the comparator and generates a select signal. The multiplexer transmits one of the reference voltages from the resistor divider to the comparator as the selected reference voltage in response to the select signal.