Semiconductor Reference Voltage Trimming for Noise Immunity
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Solution Overview
Problem
Conventional semiconductor integrated circuits face instability and errors in signal logic value discrimination due to noise-induced changes in external reference voltages, leading to power noise and distorted voltage levels, which affect operation stability.
Innovation Solution
A semiconductor integrated circuit design that includes a reference voltage pad, an internal reference voltage generator, a selector, and a voltage trimming block to selectively use either external or internal reference voltages, with the trimming block regulating the output voltage level to maintain stability, thereby isolating the circuit from external noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If external reference voltage is used to reduce device complexity, then the circuit structure is simpler, but noise from external power supply fluctuations causes voltage level distortion and operation instability
Solution Approach 1:
An internal reference voltage generator is introduced as an intermediary component between the external reference voltage pad and the input buffers. This generator creates a clean internal reference voltage that mediates the connection, blocking external noise from reaching the buffers while maintaining the external reference voltage input capability. The selector then chooses between the external and internal reference voltages, with the internal one serving as the noise-free intermediary option.
2Reliability
If internal reference voltage generator is added to improve noise immunity, then operation stability is improved, but device complexity increases
Solution Approach 1:
The internal reference voltage generator is designed to serve multiple functions: it generates a stable reference voltage from the external reference voltage, acts as a noise filter, and can be selectively switched with the external reference voltage source. This multi-functionality reduces the need for separate noise filtering circuits and voltage selection mechanisms, thereby limiting the increase in device complexity while achieving improved operation stability.
3Adaptability or versatility
If selector is used to switch between external and internal reference voltages, then adaptability is improved, but device complexity increases
Solution Approach 1:
The selector circuit is merged with the reference voltage distribution network, combining the voltage source selection function with the existing reference voltage routing infrastructure. This integration allows the selector to switch between external and internal reference voltages without requiring completely separate switching circuits for each buffer, reducing overall device complexity while maintaining adaptability.
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 ensures stable reference voltage generation, reducing noise influence and maintaining operation stability even when external power supply voltages fluctuate, ensuring accurate signal buffering and reduced error rates.
Implementation Method 1
an internal reference voltage generator that is configured to generate an internal reference voltage by voltage dividing
Data Source
AI summary
A semiconductor integrated circuit can include a reference voltage pad that can be configured to receive an external reference voltage and supply the external reference voltage to the inside of the semiconductor integrated circuit, an internal reference voltage generator that can be configured to generate an internal reference voltage by voltage dividing, a selector that can be configured to select and output one of the external reference voltage and the internal reference voltage in response to a selection signal, and a voltage trimming block that can be configured to regulate the level of the output voltage from the selector in response to trimming signals and outputs the level-regulated voltage as a reference voltage.