SMPS Control Circuit for Duty Cycle Optimization
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Solution Overview
Problem
Existing switched mode power supply (SMPS) control strategies face challenges in maintaining high power efficiency while effectively responding to voltage transients and load changes, often compromising on output voltage tolerance and transient responses.
Innovation Solution
A control circuit that generates a control signal for the duty cycle of an SMPS based on both input and output voltages, incorporating an input reference voltage generator, error signal generator, and duty cycle control signal generator to maintain a duty cycle near 100% and improve damping of oscillations due to input voltage transients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If output regulated converters use feedback control to maintain stable output voltage, then output voltage stability is improved, but power efficiency deteriorates due to reduced duty cycle
Solution Approach 1:
The patent applies dynamics by making the duty cycle adjustable and adaptive rather than fixed. The control circuit dynamically modifies the duty cycle based on operating conditions (input voltage, output voltage, load current) to optimize both efficiency and regulation performance across different scenarios
Solution Approach 2:
The patent changes the duty cycle parameter adaptively based on operating conditions. By adjusting the duty cycle according to input voltage level, output voltage requirements, and load current, the system achieves high efficiency at light loads while maintaining proper voltage regulation at heavy loads
2Loss of energy
If fixed ratio converters operate with maximised duty cycle to achieve high efficiency, then power efficiency is improved, but output voltage tolerance to transients deteriorates
Solution Approach 1:
The patent implements feedback control where the control circuit continuously monitors output voltage and load current, then adjusts the duty cycle accordingly. This feedback mechanism allows the system to maintain high efficiency while compensating for voltage transients and maintaining proper output voltage tolerance
Solution Approach 2:
The system transitions from a static fixed ratio converter to a dynamic controlled converter where the duty cycle can be adjusted in real-time based on feedback from voltage and current sensors, enabling adaptive response to transient conditions
3Stability of the object's composition
If semi-regulated converters compensate for varying input voltage, then line regulation is improved, but power efficiency deteriorates due to varying duty cycle
Solution Approach 1:
The patent optimizes the duty cycle parameter to achieve a balance between line regulation and efficiency. Rather than using aggressive duty cycle variations for regulation, the system makes subtle adjustments that maintain proper input voltage compensation while minimizing efficiency losses
Data Source
AI summary
A control circuit for a switched mode power supply (SMPS) has an input voltage reference voltage generator arranged to receive a signal indicative of an input voltage of the SMPS and is arranged to generate a reference signal directly proportional to the input voltage. An error signal generator of the control circuit is arranged to receive a signal indicative of an output voltage of the SMPS and arranged to generate an error signal based on the reference signal generated by the input reference voltage generator and based on the output voltage of the SMPS. A duty cycle control signal generator of the control circuit is arranged to generate a control signal, to control the duty cycle of the SMPS, in dependence upon the error signal.