Charging module protection and power product series

Latest update time：2024-02-05

Reads：

✦

Brief discussion on technology

Techtalk

✦

Author: Littelfuse Account Manager Rambo Liu

twenty four

Continuing from the previous chapter, this chapter mainly introduces the overcurrent, overvoltage and power control devices involved in the power module. There are many types and can be used as a reference.

AC fuse products

The commonly used fuse is 6*32mm, which can achieve higher power through parallel connection. Too many parallel connections will cause problems of current sharing and untimely protection. Therefore, a fuse with a larger current flow of 10*32mm can realize the function of 1 for 2 or 1 for 3. , improve system reliability.

DC fuse

Installed inside the distribution box, which requires larger current, and is usually installed with bolts.

Varistor

Higher temperature resistance can be achieved through improvements in outsourcing materials. At the same time, improvements in material formulas have made higher energy density possible. Now 20mm can reach 15kA surge, and 11mm can meet the 6500A surge requirements of most current choices, reducing floor space. size.

Varistor with thermal fuse

It can effectively prevent fires and add a boost to safety work.

Super junction MOSFET

Fast recovery diode series

Achieving the required hard and soft and fast reverse recovery characteristics through different doping

Driver IC

Maximum 30A low-side driving capability and silicon carbide dedicated driver IC

CAN communication ESD protection

The lightning surge low residual voltage solution mentioned in the previous article: MOV+Sidactor

In actual projects, sometimes the residual voltage of the varistor is too high. The common solutions are to choose a larger size varistor or use a 2-3 level varistor solution, or even use TVS for the third level, which not only increases the cost, but also The layout space is also occupied .

As shown below, for the single-phase power supply MOV+Sidactor solution, the abscissa is the surge voltage, and the ordinate is the residual voltage. It can be seen that MOV+Sidactor can reduce the residual voltage by 300+V, and the stress on the voltage of the downstream MOSFET/IGBT is much smaller.

At the same time, the leakage current of the MOV+Sidactor solution is smaller under high voltage. We all know that the varistor is a material device, and the number of surges is not unlimited. It will attenuate once it is hit. The leakage current may increase as a result, and it may fail later. MOV+Sidactor can extend its service life by reducing leakage current.

Asymmetric TVS, silicon carbide MOSFET driver protection solution

For the requirement of driving asymmetry, Littelfuse has developed a small package SOD-123 400W product with a negative voltage of -5V and a positive voltage of 19V. At the same time, the forward voltage can be adjusted according to customer needs. This product is asymmetrical between IGBT and silicon carbide MOSFET. Provide protection, a single TVS can achieve positive and negative voltage protection, saving board space.

Asymmetric TVS is a new product proposed for the market. Interested parties are welcome to communicate, exchange and provide opinions.