DC-DC Converter Triangular Wave Frequency Control
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Solution Overview
Problem
Existing DC-DC converters achieve fixed switching frequency control but have complex circuit structures leading to undesirable anti-noise capabilities and increased costs due to large packaging areas in chip integration.
Innovation Solution
A DC-DC converter design incorporating a triangular wave generation module and a switch control module, where the triangular wave generation module generates signals based on voltages across an energy storage inductor, and the switch control module uses these signals to control PMOS and NMOS power tubes at a preset switching frequency, simplifying the circuit structure and improving anti-noise capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a current-type DC-DC converter with peak current mode control is used to achieve fixed switching frequency, then the switching frequency can be controlled, but the circuit structure becomes complex and anti-noise capability deteriorates
Solution Approach 1:
The patent extracts the frequency control function from the complex current-mode control circuit and implements it independently through a triangular wave generation module. This module generates a triangular wave signal that directly controls the switching frequency, separating the frequency control function from the current sampling and error amplification circuits, thereby simplifying the overall circuit structure while maintaining fixed switching frequency control.
Solution Approach 2:
The control circuit is segmented into independent functional modules: a triangular wave generation module for frequency control, a error amplifier module for voltage regulation, and power tube control modules. Each module operates independently with defined interfaces, reducing interdependencies and simplifying the overall circuit structure while maintaining fixed switching frequency.
2Reliability
If a voltage-type DC-DC converter with error amplifier and third-order compensation is used, then the switching frequency can be controlled, but the occupied packaging area increases and cost increases
Solution Approach 1:
The patent removes the complex third-order compensation network from the error amplifier and replaces it with a simplified compensation approach. The triangular wave generation module is extracted as a separate frequency control unit, eliminating the need for large capacitance and resistance values required for third-order compensation, thereby reducing the occupied packaging area on the chip.
Solution Approach 2:
The patent changes the control parameter from complex multi-order voltage compensation to simple triangular wave frequency modulation. By using the triangular wave signal to directly control the switching frequency instead of relying on large compensation components, the circuit achieves fixed switching frequency control with significantly reduced component values and smaller chip area occupation.
3Reliability
If complex circuit structures are used to achieve fixed switching frequency control, then the switching frequency can be controlled, but anti-noise capability deteriorates
Solution Approach 1:
The patent extracts the frequency control function into a dedicated triangular wave generation module that operates independently from the error amplifier and power management circuits. This separation prevents noise coupling between different functional blocks and improves anti-noise capability while maintaining fixed switching frequency control.
Solution Approach 2:
The circuit is divided into noise-isolated functional segments with clear signal boundaries. The triangular wave generation module generates clean frequency reference signals that are not affected by noise from the error amplifier or power switch nodes, thereby improving overall anti-noise performance while achieving fixed switching frequency control.
Data Source
AI summary
The present invention is applicable to the field of direct current conversion, and provides a DC-DC converter. In the present invention, a DC-DC converter including a triangular wave generation module and a switch control module is adopted. The triangular wave generation module generates a triangular wave signal according to voltages at both ends of an energy storage inductor L1, and the switch control module outputs a control level according to its internally generated clock signal and the triangular wave signal to control a switching operation of a PMOS power tube and an NMOS power tube according to a preset switching frequency.