Differential Modulator Circuit for Bidirectional Isolation Links
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Solution Overview
Problem
Existing systems face challenges in performing bidirectional data transmission over isolation media due to the complicating effect of galvanic isolation, which impedes the efficient processing of received data and can cause circuit damage and safety hazards.
Innovation Solution
Implementing differential modulation techniques with specific frequency modulation and demodulation operations on differential signals to facilitate data transmission through isolation devices, utilizing transformers with reduced frequency bands and transformers with fewer coil turns to minimize attenuation and enable efficient bidirectional communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If galvanic isolation is implemented between two devices with different voltage domains, then circuit safety and protection from DC/low frequency signal damage are improved, but the ability to perform bidirectional data transmission is complicated and processing of received data becomes difficult
Solution Approach 1:
The patent applies periodic action by using alternating current (AC) coupling through the isolation medium. The isolation device blocks DC signals while allowing AC signals to pass, enabling bidirectional data transmission. The modulator circuit modulates data onto AC carriers that can traverse the galvanically isolated medium, and the demodulator recovers the original data signals, thus resolving the contradiction between safety isolation and transmission capability.
Solution Approach 2:
The patent introduces an intermediary AC coupling mechanism between the two voltage domains. The isolation device acts as a mediator that blocks harmful DC signals while permitting AC-coupled data signals to pass through. The modulator and demodulator circuits serve as intermediary components that convert data into a form suitable for transmission through the isolated medium, maintaining both safety and functionality.
2Object-affected harmful factors
If traditional isolation devices are used to block DC and low frequency signals, then circuit damage and safety hazards are prevented, but data transmission capability is impeded and processing efficiency is reduced
Solution Approach 1:
The patent applies parameter changes by transforming the data signal from DC or low-frequency baseband signals into high-frequency AC modulated signals. The modulator circuit shifts the frequency of the data signals into a range that can pass through the isolation medium's AC coupling capacitors. The demodulator then converts these high-frequency signals back to baseband, maintaining data integrity while enabling efficient transmission through the safety-isolated medium.
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 approach allows for effective bidirectional data transmission over isolation media while preventing DC and low-frequency signal flow, reducing transformer complexity and cost, and ensuring safety by minimizing circuit damage and hazards.
Implementation Method 1
A first differential modulator circuit is coupled between first differential terminals and second differential terminals... modulate first differential signals at the first differential terminals with the first differential modulation signals
Data Source
AI summary
An apparatus includes a controller having differential modulation control outputs and is configured to provide differential modulation signals having a particular frequency at the differential modulation control outputs. A differential modulator circuit is coupled between first differential terminals and second differential terminals. The differential modulator circuit has differential modulation control inputs coupled to the differential modulation control outputs. The differential modulator circuit is configured to: modulate first differential signals at the first differential terminals with the differential modulation signals having the particular frequency, provide the modulated first differential signals at the second differential terminals, modulate second differential signals at the second differential terminals with the differential modulation signals having the particular frequency, and provide the modulated second differential signals at the first differential terminals.