Pull-Up Voltage Detection Circuit for Adaptive Bus Logic Thresholds
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Solution Overview
Problem
Existing IC designs face challenges in meeting different logic threshold voltage specifications under varying pull-up voltages, leading to inventory management issues due to the need for multiple IC chip models with different eFuse settings.
Innovation Solution
A pull-up voltage detection circuit that automatically detects and adapts to different pull-up voltages using a comparator and selector circuit to determine a logic threshold voltage, enabling dynamic selection and adjustment without additional pins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple IC chip models with different eFuse settings are provided to meet different logic threshold voltage specifications under different pull-up voltages, then the logic threshold voltage specification requirement is satisfied, but inventory management complexity increases and more management efforts are required
Solution Approach 1:
The patent implements a universal IC chip design that can adapt to multiple pull-up voltage levels (1.2V, 1.8V, 3.3V, 5V) through integrated voltage detection and automatic threshold adjustment circuitry. The detection circuit automatically identifies the pull-up voltage level and configures the logic threshold voltage accordingly, eliminating the need for different eFuse settings across multiple chip models. This multi-functional approach allows a single chip model to satisfy all logic threshold voltage specifications while simplifying inventory management.
Solution Approach 2:
The patent employs dynamic parameter adjustment by detecting the pull-up voltage level and automatically changing the logic threshold voltage parameter to match the detected level. The detection circuit measures the actual pull-up voltage and switches between pre-configured threshold voltage values (e.g., 0.6V for 1.2V pull-up, 0.9V for 1.8V pull-up, 1.65V for 3.3V pull-up, 2.5V for 5V pull-up), enabling the same hardware to adapt to different voltage specifications without requiring multiple chip variants.
2Reliability
If different eFuse settings are used in different IC chip models to meet different logic threshold voltage specifications, then the logic threshold voltage requirement is met, but the number of IC chip models increases
Solution Approach 1:
The patent creates a universal IC chip model that performs multiple functions by detecting different pull-up voltage levels and automatically adjusting the logic threshold voltage accordingly. This single multi-functional chip model replaces what would otherwise require four separate chip models with different eFuse settings, thereby reducing the quantity of different chip models while maintaining compliance with all logic threshold voltage specifications across 1.2V, 1.8V, 3.3V, and 5V systems.
3Reliability
If manual configuration of eFuse settings is performed for different pull-up voltages, then logic threshold voltage specifications are met, but operation complexity and setup requirements increase
Solution Approach 1:
The patent implements a self-service mechanism where the IC chip automatically detects the pull-up voltage level and configures its own logic threshold voltage without requiring external manual intervention. The detection circuit measures the pull-up voltage and the control circuit automatically selects the appropriate threshold voltage value, enabling the device to self-configure upon power-up. This eliminates the need for manual eFuse configuration and simplifies operation while ensuring compliance with the correct logic threshold voltage specification.
Solution Approach 2:
The patent performs voltage detection and threshold configuration as a preliminary action during the power-up sequence, before the I2C communication functionality is activated. The detection circuit immediately measures the pull-up voltage when power is applied, and the control circuit pre-configures the logic threshold voltage before any communication operations begin. This preliminary configuration ensures the device is ready for immediate operation with the correct threshold settings, eliminating the need for subsequent manual setup or configuration steps.
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
Enables automatic detection and adaptation of pull-up voltages, reducing inventory management complexity and eliminating the need for multiple IC chip models.
Implementation Method 1
at least one comparator circuit, which is configured to operably compare the communication signal or a divided voltage thereof with at least one reference voltage in a detection procedure, so as to generate at least one comparison result
Data Source
AI summary
A pull-up voltage detection circuit is for use in a serial bus. The serial bus includes a communication signal. During a communication interval, the communication signal is toggled based on a pull-up voltage for communicating on the serial bus via open-drain scheme. The pull-up voltage detection circuit includes: at least one comparator circuit for comparing the communication signal or a divided voltage thereof with at least one reference voltage in a detection procedure, so as to generate at least one comparison result; and a selector circuit for selecting one of plural predetermined voltages according to the at least one comparison result. The selected predetermined voltage serves as a logic threshold voltage corresponding to the pull-up voltage. In the communication interval, the logic state of the communication signal is determined by comparing the communication signal and the logic threshold voltage for communicating on the serial bus.