AC-Coupled Signal Receiver for Mixed-Voltage Logic Interfaces
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Solution Overview
Problem
Semiconductor devices face compatibility issues due to varying operating voltages, leading to incompatible high and low voltage definitions, which traditional methods attempt to address through voltage translation or increased pin count, resulting in increased costs and power dissipation.
Innovation Solution
An integrated circuit with a receiving circuit that uses AC coupling and transition detection, employing FETs to drive internal signals independently of input signal steady-state levels, isolating the detection circuit from steady-state values via capacitive coupling, and controlling switches to manage transitions between voltage thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If voltage translation devices are added to resolve incompatible voltage ranges, then voltage compatibility between devices is improved, but chip count and power dissipation increase
Solution Approach 1:
The patent extracts the voltage level conversion function from separate translation devices and integrates it directly into the receiving circuit. The receiving circuit now directly processes signals from different voltage domains (e.g., 5V input to 3.3V internal) without requiring external level shifters, thereby eliminating the need for additional components while maintaining voltage compatibility.
Solution Approach 2:
The receiving circuit is designed with multi-functionality to handle multiple voltage ranges natively. It can directly receive signals from different voltage domains (5V, 3.3V, 2.5V, etc.) and convert them to the internal 3.3V logic level through integrated AC coupling and transition detection circuits, making a single device compatible with multiple voltage standards without additional translation hardware.
2Adaptability or versatility
If voltage translation devices are added to resolve incompatible voltage ranges, then voltage compatibility between devices is improved, but device complexity increases
Solution Approach 1:
The patent merges the voltage translation function with the receiving circuit by integrating AC coupling capacitors and transition detection logic directly into the receiver. This consolidation eliminates separate level-shifting components and reduces overall system complexity while maintaining the ability to handle multiple voltage standards.
Solution Approach 2:
The patent introduces AC coupling capacitors as intermediary elements between the input signal and the receiving circuit logic. These capacitors block DC voltage levels while allowing signal transitions to pass through, enabling the receiver to detect signal changes from different voltage domains without being affected by their steady-state voltage differences.
3Adaptability or versatility
If bringing transmitting power voltage onto receiving chip is implemented, then voltage compatibility is improved, but die and package costs increase due to more pins and pads
Solution Approach 1:
The patent extracts the high voltage signal from the receiving chip's power domain and processes it externally through AC coupling. The capacitor-based coupling allows the high-voltage signal to be transmitted and detected without requiring the receiving chip to have multiple voltage domains or additional power pins, thereby simplifying the package design.
4Adaptability or versatility
If bringing transmitting power voltage onto receiving chip is implemented, then voltage compatibility is improved, but power dissipation increases due to voltage mismatch
Solution Approach 1:
The patent uses AC coupling capacitors as intermediary elements that block DC voltage levels while allowing AC signal components to pass. This prevents direct connection between mismatched voltage domains, eliminating the need for voltage clamping or regulation circuits that would dissipate power, while still enabling signal transmission between different voltage levels.
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 efficient signal reception across different voltage ranges with reduced static current draw and minimal power dissipation, maintaining compatibility without the need for additional voltage sources or increased pin counts.
Implementation Method 1
A transition detection circuit detects a transition of the input signal, in the second signaling range, from the first state to the second state using capacitive coupling of the input signal to isolate the detection circuit from a steady-state value of the input signal
Data Source
Figure 1
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Figure 3A
AI summary
Arrangement for accepting an input signal in a first voltage range and producing an output signal in a second voltage range. A transition detection circuit (230) detects a transition from a high level to a low level of the input signal and a control circuit (245) operates a first FET to produce the low level of the output signal. A second FET is operated by the high level of the input signal to output the high level of the output signal.