Boost Converter Ripple Emulation for Stable Constant On-Time Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional boost converters for mobile electronic devices face instability and high ripple issues due to burst mode operation, which requires additional components like RC networks and current sensors for stability, increasing circuit complexity and footprint.
Innovation Solution
A boost converter design that uses sawtooth-shape voltage signals from on-time and off-time control circuits to stabilize the system without the need for an RC network or current sensor, generating a synthetic ripple in the feedback loop to provide phase margin and prevent burst mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional boost converters operate in burst mode to handle load variations, then they can adapt to different load conditions, but this causes high output voltage ripple and higher switching losses
Solution Approach 1:
The patent implements a feedback mechanism where the output voltage is continuously monitored and compared with a reference voltage. The error signal is fed back to the control circuit to adjust the duty cycle, preventing burst mode operation and maintaining stable output voltage under varying load conditions.
Solution Approach 2:
The control circuit dynamically adjusts the duty cycle in real-time based on load conditions and output voltage feedback. This dynamic control prevents the converter from entering burst mode while adapting to different load requirements, thereby reducing output ripple and switching losses.
2Stability of the object's composition
If additional components like RC networks and current sensors are added to stabilize the boost converter, then system stability is improved, but circuit complexity and footprint increase
Solution Approach 1:
The patent employs a self-service stabilization mechanism where the control circuit uses inherent circuit parameters and feedback signals to maintain stability without requiring external RC networks or current sensors. The controller automatically adjusts operating parameters based on real-time feedback, achieving stability through intelligent control rather than additional passive components.
Solution Approach 2:
The control circuit is designed to perform multiple functions: voltage regulation, stability maintenance, and adaptive load handling. By integrating these functions into a single controller that uses feedback from existing circuit nodes, the patent eliminates the need for separate stabilization components, thereby reducing circuit complexity while maintaining stability.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A boost converter comprises a comparator circuit including: a first input port configured to receive an off-time sawtooth voltage a second input port configured to receive an on-time sawtooth voltage, the comparator circuit comparing the off-time sawtooth voltage and on-time sawtooth voltage to generate trigger signal including a differential ripple voltage that is output by an output port to a power stage circuit. The boost converter further comprises a reference voltage source that provides a reference voltage to the first input port and a feedback circuit that provides the on-time sawtooth voltage to the second port, wherein the differential ripple voltage emulates an inductor current or voltage of an output capacitor of the power stage circuit.