PFC Boost Pre-Regulator With Synchronous MOSFET Loss Reduction
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Solution Overview
Problem
Switch mode power supplies in information handling systems experience inrush current issues during start-up and brown-out events, leading to over-stressing of internal components, safety circuit disconnections, and power grid perturbations, as well as significant switching losses due to reverse recovery phenomena in boost silicon diodes.
Innovation Solution
The implementation of a power supply system using synchronous switches, including a MOSFET switch and a PFC module, which regulates the input voltage through PWM signals to minimize inrush current and switching losses by gradually saturating the MOSFET switch and utilizing zero voltage transitions to reduce energy losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a boost silicon diode is used in the boost switch, then the power supply can regulate output voltage, but significant switching losses occur due to reverse recovery phenomena
Solution Approach 1:
The patent changes the operating parameters of the boost switch by implementing zero voltage switching (ZVS) transitions. The synchronous rectifier circuit ensures that the boost switch turns on only when the voltage across it is zero, eliminating reverse recovery losses. This parameter change transforms the switching operation from a lossy process to a lossless process while maintaining voltage regulation capability
Solution Approach 2:
The patent replaces the traditional passive silicon diode with an active synchronous rectifier circuit using MOSFETs. This substitution eliminates the reverse recovery phenomenon inherent in silicon diodes by using voltage-controlled switches that can be turned on and off precisely when needed, thereby eliminating switching losses while maintaining the voltage boosting function
2Power
If switch mode power supply operates at high power, then efficient power conversion is achieved, but inrush current over-stresses internal components and causes safety circuit disconnections
Solution Approach 1:
The patent implements preliminary action by using the synchronous rectifier circuit to control the timing of power transfer. Before the main power switch closes, the synchronous rectifier prepares the circuit by establishing proper voltage conditions and controlling current flow, thereby preventing inrush current spikes that would otherwise stress components and trigger safety disconnections
Solution Approach 2:
The patent employs feedback control through the synchronous rectifier circuit that monitors voltage and current conditions. The circuit uses feedback signals to adjust the switching timing and duty cycle, ensuring that power conversion operates efficiently while preventing conditions that would cause component over-stress or safety circuit activation
3Power
If switch mode power supply operates at high power, then efficient power conversion is achieved, but power grid perturbations affect other electronic devices
Solution Approach 1:
The synchronous rectifier circuit incorporates feedback control that monitors the power conversion process and adjusts switching parameters in real-time. This feedback mechanism smooths power draw from the grid by preventing abrupt current changes, thereby eliminating power grid perturbations that would affect other connected electronic devices while maintaining high conversion efficiency
Solution Approach 2:
The patent ensures continuous controlled power transfer through the synchronous rectifier circuit. By maintaining continuous regulation of current and voltage throughout the switching cycle, the circuit eliminates discontinuous current spikes and voltage sags that cause power grid perturbations, thereby protecting other electronic devices while sustaining efficient power conversion
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 approach effectively reduces inrush current and switching losses, enhancing the efficiency and reliability of the power supply by limiting power loss spikes and preventing reverse current through the MOSFET switch, thereby improving overall system performance.
Implementation Method 1
employs zero crossing detection, PWM signals, and zero voltage switching transitions to manage inrush currents and reduce switching losses
Implementation Method 2
employs zero crossing detection, PWM signals, and zero voltage switching transitions to manage inrush currents and reduce switching losses
Implementation Method 3
employs zero crossing detection, PWM signals, and zero voltage switching transitions to manage inrush currents and reduce switching losses
Data Source
AI summary
A power supply device comprises a driver circuit, a transistor switch, and a first transistor. The driver circuit is configured to provide a stable driving signal and a floating driving signal. The transistor switch has a first terminal, a second terminal connected to a first terminal of the driver circuit, and a third terminal connected to a second terminal of the driver circuit, and is configured to prevent a reverse current based on the floating driving signal. The first transistor has a first current electrode connected to the first terminal of the transistor switch, a second current electrode connected to the first voltage reference, and a control electrode connected to the third terminal of the driver circuit, and is configured to activate and deactivate based on the stable driving signal, and further configured to regulate an input voltage to a substantially constant direct current output voltage.