H-Bridge Common-Mode Control for Filterless Switching Amplifiers
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Solution Overview
Problem
H-bridge circuits operating in three states experience variations in common-mode voltage and current due to mismatches, leading to signal corruption, and existing solutions are inefficient and spatially extensive.
Innovation Solution
An H-bridge controller that receives signals indicating common-mode voltage and current, generates control signals to switch between variations of the third state operation, reducing average common-mode voltage and current variations, and includes a modulator and common-mode error determination circuit to optimize operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If H-bridge circuit operates in three states to reduce power dissipation in filterless operation, then power efficiency is improved, but common-mode voltage and current variations increase causing signal corruption
Solution Approach 1:
The patent changes the operating parameters of the H-bridge circuit by introducing controlled common-mode voltage adjustments. The controller modifies the duty cycle of switching signals to actively regulate common-mode voltage and current, transforming the fixed three-state operation into a dynamically adjustable system that maintains both power efficiency and signal integrity.
Solution Approach 2:
The patent implements a feedback mechanism where the controller receives information about the actual common-mode voltage and current levels and adjusts the switching signals accordingly. This closed-loop control ensures that power dissipation is minimized while keeping common-mode variations within acceptable limits to prevent signal corruption.
2Reliability
If existing solutions are used to control common-mode voltage variations, then signal integrity is improved, but device complexity and spatial requirements increase
Solution Approach 1:
The patent makes the controller perform multiple functions: it generates the basic switching signals for H-bridge operation, monitors common-mode voltage and current levels, and adjusts duty cycles to control common-mode variations. This multi-functional approach eliminates the need for separate control circuits, reducing overall device complexity while maintaining signal integrity.
Solution Approach 2:
The patent combines the common-mode control functionality with the existing H-bridge driver circuitry. By integrating the common-mode error determination and duty cycle adjustment functions into the single controller unit, the patent reduces spatial requirements and simplifies the overall system architecture while effectively controlling signal corruption.
Data Source
AI summary
A system includes a modulator for receiving an input signal, modulating the received input signal, and generating a digital signal, an H-bridge controller for receiving the digital signal and generating control signals, an H-bridge circuit for receiving the control signals and operating based on the received control signals so as to output an analog signal to a load, and a common-mode error determination circuit for generating an error signal indicating at least one of an error of a common-mode voltage and an error of a common-mode current of the H-bridge circuit. The H-bridge controller receives the error signal and generates the control signals based on the received digital signal and the received error signal so as to reduce variations in at least one of an average of the common-mode voltage or an average of the common-mode current of the H-bridge circuit.