Full-Bridge Class-D Driver Layout for Cross-Current Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Class-D full bridge amplifiers experience malfunctions due to cross currents generated by delay operations in switching elements, leading to uneven driver voltages and currents, which affect the amplification operation and input/output current balance.
Innovation Solution
The driver device for class-D full bridge amplifiers ensures equipotential reference potentials for high-side driver circuits and separate driver power supplies for each amplifier, preventing cross currents and uneven driver voltages by configuring the high-side driver circuits with direct current equipotential connections and individual power supplies for each amplifier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common driver power supply is used for multiple class-D full bridge amplifiers, then device complexity is reduced, but cross currents flow between amplifiers causing malfunction
Solution Approach 1:
The patent divides the driver power supply system into separate independent units for each class-D full bridge amplifier. Instead of using a common driver power supply for multiple amplifiers, each amplifier receives power from its own dedicated driver power supply. This segmentation prevents cross currents from flowing between amplifiers through the power supply, eliminating the malfunction caused by delay operations in switching elements, while maintaining manageable system complexity through modular architecture.
2Reliability
If high-side driver circuits are connected with different reference potentials, then electrical isolation is achieved, but driver voltage becomes uneven causing malfunction
Solution Approach 1:
The patent establishes equipotential connections for the reference potentials of high-side driver circuits within each class-D full bridge amplifier. By configuring the high-side driver circuits to have the same reference potential, the patent ensures uniform driver voltages are applied to the switching elements, preventing malfunction due to voltage imbalance. This equipotential configuration is implemented independently in each amplifier with its own driver power supply, maintaining both electrical isolation between amplifiers and voltage uniformity within each amplifier.
Data Source
AI summary
The present invention suppresses unevenness of an input/output current of a full bridge circuit, which is caused due to a cross current generated by a delay operation or the like of a switching element and unevenness of a driver voltage of each switching element, and suppresses an occurrence of an erroneous operation of an amplifier of a class-D full bridge circuit. A driver device of a class-D full bridge amplifier according to the present invention sets, at the same potential in terms of DC, reference potentials on a low-voltage side of two high-side driver circuits which drive two high-side switching elements which constitute a full bridge circuit, and suppresses an occurrence of unevenness of a driver voltage of the switching elements due to a cross current which flows between the bridge circuit and the high-side driver circuits. In the configuration in which a plurality of class-D full bridge amplifiers are driven, a driver power supply is individually provided to driver circuits which drive the class-D full bridge amplifiers, and cross currents which flow between the plurality of class-D full bridge amplifiers are suppressed.