Multi-Channel Amplifier Phase Shifting for Lower EMI Ripple
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Solution Overview
Problem
Conventional amplification systems, such as those using Class-D amplifiers, face challenges in efficiently processing multiple input signals due to phase alignment issues between channels, leading to increased ripple in the power supply and potential electromagnetic interference.
Innovation Solution
The implementation of multiple channels with phase-shifted ramp signals, where each channel processes input signals with a unique phase, and the use of periodic or pseudo-random jittering in the oscillator frequency to improve signal processing and reduce electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple channels share a common ramp signal, then device complexity is reduced, but power supply ripple and electromagnetic interference increase
Solution Approach 1:
The patent divides the common ramp signal into multiple phase-shifted ramp signals for different channels. Each channel receives a ramp signal with a different phase (e.g., 0°, 120°, 240°), which segments the original single ramp signal into multiple distinct signals. This segmentation reduces simultaneous switching across all channels, thereby reducing power supply ripple and electromagnetic interference while maintaining relatively simple circuit architecture.
Solution Approach 2:
The patent implements periodic phase shifting of ramp signals across channels. By cycling through different phase combinations in a periodic manner, the system distributes the switching activity over time, preventing concentrated ripple and interference events. This periodic action maintains low complexity while effectively managing electromagnetic interference.
2Ease of operation
If multiple channels use the same phase ramp signal, then ease of operation is improved, but signal processing effectiveness deteriorates
Solution Approach 1:
The patent introduces dynamic phase shifting to the ramp signals, where each channel's ramp signal phase is dynamically adjusted relative to others. This dynamic approach allows the system to optimize signal processing for different operating conditions while maintaining a relatively simple fixed architecture. The dynamic phase relationships improve signal processing effectiveness without requiring complex reconfigurable circuits.
Solution Approach 2:
The patent changes the phase parameter of ramp signals for different channels. By varying the phase angle parameter (e.g., setting channels to 0°, 120°, 240° phases), the system improves signal processing effectiveness through better spectral distribution and reduced interference, while the underlying circuit architecture remains simple and easy to operate.
3Stability of the object's composition
If oscillator frequency is fixed, then stability is improved, but electromagnetic interference increases
Solution Approach 1:
The patent applies periodic frequency modulation (jittering) to the oscillator, where the frequency varies periodically within a small range around a nominal value. This periodic variation prevents the oscillator from consistently operating at a single frequency that could cause electromagnetic interference, while maintaining overall frequency stability for proper system operation. The jittering effect distributes electromagnetic energy across a broader frequency spectrum, reducing peak interference.
Data Source
AI summary
Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different.