Interface Circuit with Adaptive Reference Voltage and Clock Phase
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Solution Overview
Problem
Existing interface circuits face challenges in maintaining a sufficient noise margin during high-speed data transfer, particularly due to ground potential differences and electromagnetic interference, which limits their effectiveness in high-frequency operations and increases the complexity and cost of wiring.
Innovation Solution
An interface circuit with a detecting unit that adjusts the reference voltage and clock phase based on the transition states of logic levels in received binary data signals, allowing for dynamic control of the reference voltage and clock phase to enhance noise margin and reduce electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed reference voltage is used, then the circuit structure is simple, but the noise margin is narrowed due to ground potential difference
Solution Approach 1:
The reference voltage is changed from a fixed value to a dynamically adjustable value that adapts to different operating conditions. The reference voltage control unit modifies the reference voltage based on detected signal characteristics, enabling the circuit to maintain adequate noise margin while accommodating ground potential differences without requiring complex differential wiring.
2Reliability
If the reference voltage is dynamically controlled after data reception, then the noise margin is improved, but the data cannot be captured by storage means before reference voltage adjustment
Solution Approach 1:
The detecting unit performs preliminary detection of the received signal characteristics before the reference voltage is adjusted. This allows the system to prepare the appropriate reference voltage in advance, enabling storage means to capture data at the correct timing without waiting for reference voltage stabilization, thus eliminating the timing conflict.
Solution Approach 2:
The detecting unit continuously monitors the received signal and provides feedback to the reference voltage control unit. This feedback mechanism enables real-time adjustment of the reference voltage based on actual signal conditions, ensuring that the reference voltage is optimally set for data capture while maintaining noise margin protection.
3Reliability
If a differential transfer system is used, then the noise margin is enlarged, but the wiring complexity and cost increase
Solution Approach 1:
The reference voltage control unit acts as an intermediary that compensates for ground potential differences and noise effects without requiring differential signaling. By dynamically adjusting the reference voltage to match the transmitted reference voltage characteristics, the system achieves noise immunity equivalent to differential transfer but with simpler single-ended wiring.
4Productivity
If synchronous transfer with simultaneous clocking is used, then the data transfer is coordinated, but electromagnetic interference and power supply noise increase
Solution Approach 1:
The clock phase control unit applies local phase adjustment to individual clock signals based on their specific routing characteristics and load conditions. This staggered clocking approach maintains data transfer coordination while distributing the electromagnetic interference over time, reducing peak EMI levels and power supply noise compared to simultaneous clocking of all storage means.
Data Source
AI summary
An interface circuit capable of controlling a noise margin and a time margin for producing an output a binary data is realized. The circuit comprises a detecting unit for detecting a transition state of logic levels in received binary data corresponding to preceding two clock signals, an output signal producing unit for producing an output binary data based on the received binary data by using a reference voltage and by latching the binary data using the clock signal, a reference voltage control unit for controlling the reference voltage, and a clock phase control unit for controlling a phase of the clock signal. The noise margin can be controlled by changing the reference voltage in accordance with the detected transition state, and the time margin can be controlled by changing the clock phase in accordance with the detected transition state.