DC-to-DC Converter Ripple Compensation Feedback Bandwidth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current DC-to-DC converters in information handling systems face limitations in feedback loop bandwidth due to error amplifier output voltage ripple, which restricts loop gain and frequency response, necessitating additional output capacitors and increased costs.
Innovation Solution
The introduction of a ripple compensation mechanism using a pulse width modulation (PWM) generator, a ripple compensation voltage capacitor, and a high pass filter/scaler to synthetically generate and cancel the non-linear loop dynamics caused by output voltage ripple, thereby reducing the need for additional output filter capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the bandwidth of the DC-to-DC converter regulation feedback loop is increased to maintain voltage tolerance range during rapid current changes, then the voltage regulation performance is improved, but the error amplifier output voltage ripple increases which limits further bandwidth improvement
Solution Approach 1:
The patent measures the error amplifier output voltage ripple (harmful factor) and uses it to generate a compensation signal that is injected back into the feedback loop. By converting the harmful ripple into a useful compensation signal, the system achieves extended bandwidth without being limited by the original ripple problem.
Solution Approach 2:
The patent implements a feedback mechanism where the error amplifier output voltage ripple is measured and fed back through a compensation network. This feedback loop allows the system to dynamically adjust and cancel the ripple effects, enabling higher bandwidth operation.
2Stability of the object's composition
If additional output filter capacitors are added to maintain voltage regulation during large current steps, then the voltage stability is improved, but the cost and device complexity increase
Solution Approach 1:
The patent extracts and measures the voltage ripple component from the error amplifier output, separates it from the main feedback signal, and processes it through a compensation network. This extraction allows the ripple to be compensated independently without requiring additional bulk capacitance.
Solution Approach 2:
The patent changes the parameters of the feedback loop by introducing a compensation network that modifies the feedback signal characteristics. By adjusting the compensation network parameters (resistors, capacitors), the system achieves improved voltage stability without adding physical capacitors to the output filter.
Data Source
AI summary
Control loop ripple voltage in an error amplifier may be the result of a non-linear time varying behavior of a switch mode power conversion process. An inverse waveform replica of the error amplifier control loop ripple voltage waveform may be generated to substantially cancel the non-linear loop dynamics introduced by the control loop ripple voltage. Once the control loop ripple voltage is substantially cancelled the bandwidth of the DC-to-DC converter control loop may be increased for faster loop response thus reducing the need for additional output filter capacitance.