With the continuous advancement of electronic technology, the field of power supply design is also constantly innovating. In recent years, the use of mosfets instead of synchronous rectifier diodes in circuit schemes has gradually attracted widespread attention. This article will delve into the principles and advantages of this technology, helping you better understand this cutting-edge technology.

What is synchronous rectification?

Synchronous rectification is a rectification technology that uses active switching elements (such as MOSFETs) instead of traditional diodes. Traditional diodes experience a certain forward voltage drop during conduction, resulting in energy loss. Synchronous rectification, on the other hand, significantly reduces conduction losses and improves overall efficiency by precisely controlling the switching state of MOSFETs.

Advantages of MOSFET

Low on resistance: MOSFETs have lower on resistance compared to diodes, which can reduce energy loss and improve efficiency. This is particularly evident in high-frequency and high-power applications.

Fast switching characteristics: MOSFETs have faster switching speeds, which can effectively reduce switching losses. This makes it perform better in high-frequency applications and helps improve overall system performance.

Better thermal management: Due to the lower operating temperature of MOSFETs, it can reduce the complexity of heat dissipation design and improve system stability.

The working principle of MOSFET in synchronous rectification

In synchronous rectification circuits, MOSFETs are commonly used as switching elements. In the positive half cycle of the power supply, the MOSFET conducts, allowing current to pass through, while the diode is in the off state; In the negative half cycle, the MOSFET is turned off and the diode is turned on. By controlling the switching of MOSFETs, energy loss during rectification can be effectively reduced.

Drive signal: The switching state of MOSFET is controlled by a drive signal, usually using PWM (Pulse Width Modulation) signal. This method can accurately control the switching timing of MOSFET, ensuring the optimal conduction time and turn off time.

Feedback mechanism: In order to improve efficiency and stability, many designs have introduced feedback mechanisms to monitor the output voltage and adjust the switching frequency and duty cycle of MOSFETs as needed.

Application scenarios

MOSFET synchronous rectification technology is widely used in fields such as switching power supplies, battery chargers, and DC-DC converters. Especially in these applications, high efficiency is required, and using MOSFETs can significantly improve overall performance.

Conclusion

The technology of replacing synchronous rectifier diodes with MOSFETs not only improves rectification efficiency, but also brings many advantages in thermal management and system stability. With the continuous improvement of energy efficiency requirements for electronic products, synchronous rectification technology using MOSFETs will play an increasingly important role in future power supply designs.

Fushite Technology focuses on the field of power devices, providing customers with power devices such as IGBT and IPM modules, as well as MCU and touch chips. It is an electronic component supplier and solution provider with core technology.