Low-Voltage Buck Regulator Switching for Faster Transient Settling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Buck converters face challenges in maintaining output voltage stability during extreme load transients, leading to overshoot and prolonged settling times, which can result in incorrect fault indications in safety-critical applications.
Innovation Solution
A selectively connectable transient suppression circuit is introduced, comprising a dissipation circuit and a suppression circuit switch controlled by a voltage monitor and trigger, which connects or disconnects the dissipation circuit based on voltage thresholds and switching frequency, facilitating charge balancing between output capacitors to reduce overshoot and settling time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard buck converter is used, then the circuit is simple and lightweight, but the output voltage exhibits overshoot and prolonged settling time during load transients
Solution Approach 1:
A transient suppression circuit is introduced as an intermediary component between the buck converter output and the load. This circuit includes a suppression capacitor connected in parallel with the output capacitor, and a suppression switch that selectively connects or disconnects the suppression capacitor based on transient detection, thereby mediating the voltage stabilization process during load transients
Solution Approach 2:
The suppression switch dynamically connects or disconnects the suppression capacitor based on real-time voltage monitoring. During load transients when voltage deviates from the threshold, the switch closes to enable the suppression capacitor to counteract voltage changes. When voltage stabilizes, the switch opens to remove the additional component, thus adapting the circuit behavior to transient conditions
2Reliability
If output capacitance is increased to reduce overshoot, then voltage stability improves, but power consumption increases
Solution Approach 1:
Instead of using a permanently connected large suppression capacitor that would continuously consume power, the circuit employs a suppression switch to dynamically connect the capacitor only when transients are detected. The switch monitors the output voltage and closes the suppression capacitor into the circuit only when voltage deviates from the threshold, thereby providing voltage stabilization only when needed and minimizing continuous power consumption
Solution Approach 2:
The suppression circuit operates periodically by detecting voltage transients and activating the suppression capacitor only during transient events. The suppression switch monitors voltage continuously and triggers the suppression capacitor discharge or charge action only when voltage exceeds or falls below the threshold, creating a periodic on-demand operation pattern rather than continuous operation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves significant reductions in overshoot and settling time, preventing nuisance trips and ensuring accurate fault indication in safety-critical applications, with improved power density and reduced power consumption.
Implementation Method 1
a dissipation circuit and a suppression circuit switch connected in series with the dissipation circuit that controls charge dissipation from the DC output into the dissipation circuit
Data Source
Figure 1
Figure 2A~2B
Figure 2C
AI summary
A power converter for providing power to a load includes a buck converter (301) having a DC input (302) and a DC output (304) and that is configured to receive a DC voltage at the DC voltage input and provide DC output voltage at the DC output. The converter also includes a voltage monitor (320) that monitors a voltage provided at the DC output and a selectively connectable transient suppression circuit (340) connected across that DC output and connected to the voltage monitor. The selectively connectable transient suppression circuit includes a dissipation circuit (370) and a suppression circuit switch (SW1) connected in series with the dissipation circuit that controls charge dissipation from the DC output into the dissipation circuit based on the voltage monitor determining that the voltage across the DC output is above a threshold.