SMPS Controller Architecture Without VCC-Sampling Capacitors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional high-side buck AC/DC switch-mode power supply (SMPS) systems face challenges in achieving ultra-low standby power dissipation due to the use of a VCC-sampling capacitor, which results in poor load regulation and dynamic characteristics, and the indirect sampling of the output voltage.
Innovation Solution
An SMPS controller with a built-in energy storage unit and logic control unit, powered by an output-voltage power supply unit, eliminates the need for a stand-off capacitor, integrating these components in a single package to reduce standby power dissipation and improve load regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a VCC-sampling capacitor is used to power the control chip from the output voltage, then standby power dissipation is reduced, but load regulation and dynamic characteristics deteriorate
Solution Approach 1:
The power supply function is segmented into two independent paths: a VCC power supply unit that provides operating voltage to the control chip, and a separate output voltage sampling path that directly samples the output voltage without using a capacitor. This segmentation allows the control chip to be powered efficiently while maintaining accurate output voltage sampling for proper load regulation.
Solution Approach 2:
The VCC-sampling capacitor is extracted and removed from the circuit. Instead of using a capacitor to both power the control chip and sample the output voltage, the patent separates these functions: the VCC power supply unit handles power delivery while a dedicated sampling circuit handles output voltage measurement, eliminating the performance degradation caused by capacitor-based sampling.
2Loss of energy
If a VCC-sampling capacitor is used to power the control chip from the output voltage, then standby power dissipation is reduced, but dynamic characteristics deteriorate
Solution Approach 1:
The power supply and voltage sampling functions are segmented into separate circuits. The VCC power supply unit provides stable operating voltage to the control chip, while the dedicated sampling circuit directly measures output voltage changes, enabling fast dynamic response without the voltage ripple and delay introduced by capacitor charging/discharging cycles.
Solution Approach 2:
The VCC-sampling capacitor is extracted from the circuit, removing the bottleneck that limited dynamic performance. The separate sampling circuit can respond immediately to output voltage changes, improving transient response and dynamic characteristics while the VCC power supply unit maintains efficient standby power consumption.
3Ease of operation
If a stand-off capacitor is used for sampling the output voltage, then the control chip can be powered from the output voltage, but the system complexity increases
Solution Approach 1:
The VCC power supply unit and the output voltage sampling function are merged into an integrated controller chip. This integration eliminates the need for external stand-off capacitors and separate sampling components, reducing system complexity while maintaining the ability to power the control chip from the output voltage and accurately sample the output voltage for regulation.
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
This solution significantly reduces standby power dissipation and enhances dynamic characteristics by maximizing the utilization of the output voltage, minimizing the contribution of a high-voltage power supply, and allowing for miniaturization and simplification of the SMPS system.
Implementation Method 1
a built-in energy storage unit... configured to charge the built-in energy storage unit using an output voltage from the switch-mode power supply system
Data Source
AI summary
A switch-mode power supply (SMPS), an SMPS system and a power supply method for an SMPS system are disclosed. The SMPS controller includes an output-voltage power supply unit, a built-in energy storage unit and a logic control unit. The output-voltage power supply unit is configured to charge the built-in energy storage unit using an output voltage from the SMPS system so that the built-in energy storage unit can provide an operating voltage for the logic control unit. The use of a stand-off energy storage capacitor can be dispensed with, and the use of the output voltage as a power supply is enabled. As a result, significant reductions in overall and standby power dissipation are achieved. In addition, the SMPS controller may further include a high-voltage power supply unit, which provides a hybrid power supply solution, together with the output-voltage power supply unit.