Reference Voltage Control for Power Supply Ripple Regulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power supplies face challenges in maintaining accurate voltage regulation, particularly in diode emulation mode due to high ripple voltage, making it difficult to keep the output voltage within the desired range.
Innovation Solution
The implementation of a power supply system that includes a reference voltage generator, a power supply phase, and an adjustor circuitry, which produces a reference voltage and adjusts it based on feedback signals to maintain the output voltage within a desired setpoint, using error voltage and ripple current monitoring to ensure precise regulation, and switching between diode emulation and continuous conduction modes based on load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional power converter operates in diode emulation mode, then the output voltage can be regulated while using simple switch circuitry, but high ripple voltage makes it difficult to maintain the output voltage within the desired range
Solution Approach 1:
The patent introduces a capacitor connected between the output node and ground as an intermediary element. This capacitor filters the high ripple voltage generated in diode emulation mode, allowing the simple switch circuitry to be used while achieving acceptable output voltage regulation. The capacitor acts as a mediator that decouples the ripple generation from the output voltage stability.
Solution Approach 2:
The patent modifies the operating parameters by introducing a minimum off-time constraint for the switch circuitry. This parameter change allows the converter to operate in diode emulation mode with controlled ripple characteristics, balancing the simplicity of the circuit with the need for voltage regulation accuracy.
2Ease of operation
If the switch circuitry is occasionally pulsed to maintain regulation in diode emulation mode, then the output voltage can be controlled, but the ripple voltage increases making regulation more difficult
Solution Approach 1:
The output capacitor serves as an intermediary that absorbs the ripple voltage generated by the pulsed switch operation. This allows the control mechanism to function effectively while the capacitor mitigates the harmful ripple effect, enabling voltage control without suffering from high ripple.
Solution Approach 2:
The patent converts the harmful ripple voltage into a beneficial filtering opportunity. By deliberately designing the output stage with adequate capacitance, the ripple energy is absorbed and converted into smooth output voltage, transforming the harmful effect into a demonstration of effective energy storage and release.
3Device complexity
If a fixed ON-time buck converter uses off-time PWM to regulate output voltage, then the converter structure is simplified, but maintaining precise voltage regulation becomes more difficult
Solution Approach 1:
The patent implements dynamic control by using off-time PWM where the off-time duration varies based on the error signal. This dynamic adjustment of the off-time parameter allows precise voltage regulation while maintaining the simplified fixed ON-time structure, achieving both simplicity and precision through time-varying control.
Solution Approach 2:
The patent incorporates feedback control by comparing the actual output voltage with the reference voltage and using the error signal to modulate the off-time duration. This feedback mechanism enables precise voltage regulation despite the simplified converter structure, as the control loop continuously corrects any deviations.
Data Source
AI summary
A power supply includes a reference voltage generator, a power supply phase, and an adjustor. During operation, the reference voltage generator produces a reference voltage. The power supply phase produces an output voltage to power a load as a function of an output voltage feedback signal derived from the output voltage and the reference voltage. The adjustor adjusts a magnitude of the reference voltage to maintain regulation of the output voltage with respect to a desired voltage setpoint.