Phase Controller Latency Generator for PWM Edge Collision Avoidance
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Solution Overview
Problem
Existing phase controllers face challenges in preventing edge collisions between pulse signals from PWM circuits, which can cause switching noise and waveform disturbances, especially when feedback control dynamically changes pulse widths, making it difficult to avoid collisions between on and off edges.
Innovation Solution
A phase controller that dynamically generates latency in pulse signals to prevent edge collisions by using a latency control circuit to calculate and adjust phase differences between channels, reducing computational complexity through table generation and bit shift operations, allowing for real-time collision avoidance without feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed phase difference is added between PWM circuit channels to avoid edge collision, then on-edge collision is avoided, but off-edge collision cannot be avoided and computational complexity increases when pulse width dynamically changes
Solution Approach 1:
The patent pre-calculates and stores latency values in a table for different pulse width combinations before actual operation. When pulse widths change dynamically, the system simply looks up the pre-computed latency values rather than performing complex real-time calculations, thus avoiding edge collisions while maintaining low computational complexity
Solution Approach 2:
The patent dynamically adjusts the latency applied to each channel based on the actual pulse width values. By monitoring changes in pulse widths and selecting appropriate latency values from the pre-computed table, the system adapts to dynamic conditions without requiring complex real-time computation
2Measurement precision
If pulse width is updated in short units (several hundred Hz or less) to improve control precision, then responsiveness is improved, but collision avoidance computation must be performed in extremely short time intervals increasing computational burden
Solution Approach 1:
The patent pre-computes latency values for all possible pulse width combinations and stores them in a lookup table. This allows the system to respond to rapid pulse width changes (several hundred Hz or less) by simply retrieving pre-computed values rather than performing complex calculations in real-time, thus maintaining both high control precision and fast computation speed
3Device complexity
If multiple PWM circuits share the same power supply to reduce device complexity, then device complexity is reduced, but switching noise and power supply fluctuation increase when pulse signals change simultaneously
Solution Approach 1:
The patent pre-calculates appropriate latency values to stagger the switching events of multiple PWM circuits. By applying different latencies to each channel based on pre-computed values, the system ensures that pulse signals do not change simultaneously, thereby reducing switching noise and power supply fluctuations while maintaining a simple shared power supply architecture
Solution Approach 2:
The patent applies preliminary latency adjustment to prevent simultaneous switching of multiple PWM circuits. By proactively staggering the pulse signals through pre-computed latency values, the system prevents the occurrence of switching noise and power supply fluctuations before they can happen
Data Source
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AI summary
A phase controller includes a plurality of pulse width modulation (PWM) circuits, a plurality of switching devices, a computing unit, and a latency generator. The plurality of PWM circuits output pulse signals. The plurality of switching devices are coupled to the respective plurality of PWM circuits, and switch on and off based on the pulse signals. The computing unit calculates the pulse signals to be output from the plurality of PWM circuits, based on outputs of the plurality of switching devices. The latency generator generates latency in any of the pulse signals so that edge positions of the pulse signals output from the plurality of PWM circuits do not collide with each other, wherein the pulse signals change values at the edge positions.