How to choose the right bridge for quick recovery

How to choose the right bridge for quick recovery

The fast reverse recovery characteristic of the fast recovery bridge is widely used in high-frequency circuits such as switching power supplies, inverters, UPS power supplies, etc. Choosing a suitable fast recovery bridge can not only improve the conversion efficiency of the circuit, but also effectively reduce switch losses and electromagnetic interference.

1. Determine voltage and current parameters

The primary parameters of a fast recovery bridge are its reverse voltage (VR) and forward current (IF). The reverse voltage should be selected with a safety margin 20% -30% higher than the actual operating voltage to ensure that it will not break down under various operating conditions. For example, in a 300V circuit, it is reasonable to choose a fast recovery bridge with a withstand voltage of 400V-500V.

The selection of forward current should be based on the load current of the circuit. It is generally recommended to choose a fast recovery bridge that is 1.5 to 2 times greater than the maximum load current to prevent overload under peak load. Especially in high current applications, the surge current capability of the fast recovery bridge needs to be considered to ensure that it can withstand instantaneous high current surges.

2. Reverse recovery time (trr)

Reverse recovery time (trr) is one of the core parameters of the fast recovery bridge. It represents the time required for the diode to transition from a conducting state to a cutoff state. The shorter the reverse recovery time, the lower the switch loss, making it suitable for use in high-frequency circuits. Generally speaking, in applications with high switching frequencies, such as power converters above 50kHz, choosing a fast recovery bridge with reverse recovery time in the tens of nanoseconds (ns) level can significantly improve system efficiency and reduce heat loss.

3. Temperature characteristics and heat dissipation design

The fast recovery bridge generates heat during operation, and temperature has a direct impact on its performance. The working temperature range should generally be between -40 ° C and+150 ° C. In high temperature environments, the performance of fast recovery bridges may decrease, so special attention needs to be paid to their working environment and heat dissipation design. To ensure stable operation, the fast recovery bridge should be equipped with sufficient heat dissipation measures, such as installing heat sinks or using thermal conductive materials, to maintain its operating temperature within a safe range.

4. Positive pressure drop and efficiency

The forward voltage drop (VF) of the fast recovery bridge has a direct impact on the overall efficiency of the circuit. A lower forward voltage drop means less energy loss and higher circuit efficiency. Especially in power applications that require high efficiency, choosing a low voltage drop fast recovery bridge can help reduce power consumption and improve system performance.

5. Packaging form and installation method

Choosing the appropriate packaging form based on the spatial layout and power density requirements of the circuit board is also a key factor. There are various packaging forms for fast recovery bridges, such as SMD (surface mount), DIP (direct insertion), TO-220, GBJ, etc. For designs with limited space, SMD packaging can be chosen; In applications that require high heat dissipation capacity, TO-220 packaging is a common choice as it can better manage heat dissipation.

6. Reliability and Electromagnetic Compatibility

When choosing a fast recovery bridge, its reliability and electromagnetic compatibility (EMC) should also be considered. Choosing a fast recovery bridge with high reliability can reduce circuit failure rates and extend system lifespan. For occasions with high requirements for electromagnetic compatibility, products with good EMC characteristics should be selected, or filtering circuits should be added to the design to suppress electromagnetic interference caused by the switching process.

The selection of YFW fast recovery bridge is a complex process that requires comprehensive consideration of various factors such as voltage, current, reverse recovery time, temperature characteristics, packaging form, etc. Proper selection can significantly improve the performance and reliability of circuits. In practical applications, engineers should select the most suitable fast recovery bridge model based on specific circuit requirements, combined with the manufacturer's product parameters and recommendations.