Voltage Conversion Circuit Feedback Branch for Noise Reduction
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Solution Overview
Problem
Voltage conversion circuits face inaccuracies in controlling output voltage during the switched-off state of an electric load due to limited time for voltage control, leading to potential inaccuracies and increased switching noise.
Innovation Solution
A voltage conversion circuit with a feedback branch that includes a charge store and comparison circuit, allowing for continuous sensing of voltage variations by generating control signals during both the switched-on and switched-off states of a pulse-width modulated clock signal, using a first potential during the on-state and a second potential derived from the charge store during the off-state, which are compared to a reference voltage to improve accuracy and reduce switching noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage control is performed only during the switched-on state of the electric load, then the control circuit can operate with simpler timing, but the voltage control accuracy deteriorates due to limited control time
Solution Approach 1:
The feedback branch is segmented into two distinct sensing paths: a first sensing path that operates during the switched-on state of the electric load, and a second sensing path that operates during the switched-off state. This segmentation allows the circuit to gather voltage information from both states independently, improving overall voltage control accuracy without requiring complex simultaneous operation of all components
Solution Approach 2:
The feedback branch implements periodic sensing actions that alternate between the first sensing period (when the electric load is switched on) and the second sensing period (when the electric load is switched off). This periodic action ensures continuous voltage monitoring across complete PWM cycles, maintaining accurate voltage control while using simple, sequentially-operating circuit components
2Use of energy by moving object
If the electric load is switched off for extended periods, then energy consumption is reduced, but voltage control accuracy deteriorates due to insufficient sensing time
Solution Approach 1:
The first charge store is configured to hold the second potential (sensed during the switched-off state) in advance, so that this voltage information is readily available when the next sensing cycle begins. This preliminary storage of voltage data ensures that even if the switched-off period is extended for energy savings, the control system still has accurate voltage information from the previous cycle to maintain control accuracy
Solution Approach 2:
The feedback branch maintains continuous useful action by seamlessly transitioning between sensing during the switched-on state and sensing during the switched-off state. The charge stores ensure that voltage information is continuously available across state transitions, so that voltage control accuracy is maintained regardless of the duration of either state, allowing extended switched-off periods for energy efficiency
3Measurement precision
If voltage sensing is performed during both switched-on and switched-off states, then voltage control accuracy improves, but switching noise increases due to additional circuit switching
Solution Approach 1:
Charge stores are introduced as intermediary elements that buffer the voltage sensing operations. These charge stores capture voltage information during switching transitions and hold it steady for comparison, acting as intermediaries that isolate the sensitive comparison circuit from the noisy switching events. This allows accurate voltage sensing during both states while minimizing the propagation of switching noise to the control signal
Solution Approach 2:
The harmful switching noise is extracted and isolated from the main control path by performing voltage sensing on the second potential (at the second output) during the switched-off state, when the main power switching is inactive. This separates the critical voltage measurement function from the noisy switching operations, allowing accurate sensing without introducing additional switching noise into the control loop
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
Enables more accurate control of output voltage and reduces switching noise by allowing continuous monitoring and control of voltage variations, even during the switched-off state, enhancing the precision and efficiency of voltage regulation.
Implementation Method 1
A feedback branch is provided which comprises a first charge store with a first end coupled to the second output and comprises a comparison circuit
Data Source
AI summary
A voltage conversion circuit comprises a first and a second output (O1, O2) which are configured to have an electric load (LD) connected therebetween, wherein an output signal between the first and a second output (O1, O2) is generated in response to a pulse-width modulated clock signal (PWM). The circuit further comprises a forward branch (FWD) being configured to generate an output voltage (VDC) at the first output (O1) depending on a control signal. A feedback branch (FBK) comprises a comparison circuit (CC) being configured to generate the control signal. The feedback branch (FBK) is configured to provide a first potential corresponding to a voltage (VSINK) at a second output (O2) to a comparison input (CI) of the comparison circuit (CC) during a first sensing period which corresponds to at least a part of a period of a first state of the clock signal (PWM) and to provide a second potential derived from the voltage (VSINK) at a second output (O2) by means of a first charge store (C1) to the comparison input (CI) during a second sensing period which corresponds to a part of a period of a second state of the clock signal (PWM).