DC-DC Converter Ripple Signal Generator for Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
DC-DC converters using ceramic capacitors with smaller equivalent series resistance (ESR) face stability issues due to reduced ripple signals, which can worsen the accuracy of output signals, and conventional solutions to enhance stability often compromise output accuracy.
Innovation Solution
A DC-DC converter design incorporating a controller, two switches, an inductor, and a ripple signal generator that generates a ripple signal in-phase with the inductor current and resets it to a specific voltage every cycle, using two circuit groups in an interleaving manner to improve stability while maintaining output accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a ceramic capacitor with smaller ESR is used, then the DC-DC converter can operate with modern low-ESR components, but the stability of the converter deteriorates due to reduced ripple signal
Solution Approach 1:
The patent introduces a ripple signal generator as an intermediary component that artificially generates a ripple signal to compensate for the insufficient natural ripple signal produced by low-ESR ceramic capacitors. This mediator restores the necessary ripple signal strength to maintain converter stability without requiring high-ESR capacitors.
Solution Approach 2:
The patent changes the parameter of ripple signal characteristics by generating an artificial ripple signal with specific amplitude and frequency characteristics that match the requirements for stable converter operation. The ripple signal generator adjusts the signal parameters to compensate for the low ESR of ceramic capacitors.
2Stability of the object's composition
If an additional signal path is added to increase ripple signal strength, then the stability improves, but the output signal accuracy deteriorates
Solution Approach 1:
The patent employs asymmetric circuit configuration where the ripple signal generator is connected in a specific asymmetric manner to the feedback network, allowing the ripple signal to be injected only into the stability-critical path while keeping the output measurement path unaffected. This asymmetric arrangement enables stability improvement without compromising output accuracy.
Solution Approach 2:
The patent segments the signal paths by separating the ripple signal generation function from the output signal path. The ripple signal is generated and injected into the feedback network through dedicated circuitry, while the output signal remains on a separate clean path, preventing degradation of output accuracy.
3Stability of the object's composition
If the ripple signal is continuously generated without reset, then the stability is maintained, but the output voltage accuracy deteriorates due to drift
Solution Approach 1:
The patent implements periodic action by resetting the ripple signal to a specific voltage level at regular intervals (every switching cycle). This periodic reset prevents signal drift while maintaining the ripple signal's stabilizing effect during the active period, thereby preserving both stability and output voltage accuracy.
Solution Approach 2:
The patent uses feedback mechanisms where the ripple signal generator is controlled by the switching state of the converter, and the reset operation is triggered by feedback from the switching cycle. This feedback ensures the ripple signal is regenerated and reset at appropriate moments to maintain both stability and accuracy.
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 enhances the stability and accuracy of the DC-DC converter by compensating for the smaller ripple signals, ensuring consistent output voltage levels and improved operational stability.
Implementation Method 1
The inductor is coupled between the first node and an output node, and is configured to receive a first signal from the first node to generate the output signal at the output node
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention provides a DC-DC converter, wherein the DC-DC converter includes a controller, a first switch, a second switch, an inductor and a ripple signal generator. The controller is configured to generate an up signal and a down signal according to an output signal and a ripple signal. The first switch is coupled between an input voltage and a first node, and is controlled by the up signal. The second switch is coupled between the first node and a reference voltage, and is controlled by the down signal. The inductor is coupled between the first node and an output node, and is configured to receive a first signal from the first node to generate the output signal at the output node. The ripple signal generator is configured to generate the ripple signal, and reset the ripple signal every cycle to a specific voltage.