Power module customization takes you to understand module power circuit analysis

Power module customizationTake you to understand the analysis of the module power circuit, the module power circuit has an input protection circuit and an output overvoltage protection circuit!

(1) Input protection circuit

Generally, the company's products have built-in filters, which can meet the requirements of general power supply applications. However, if the power supply system requires higher requirements, an input filter network can be added. A simple LC or p-type network can be used, but in the design process, care should be taken to choose a smaller inductance and a larger capacitance as much as possible.

An aluminum electrolytic capacitor should be added to the input to absorb the voltage spike at the input of the module and provide a certain maintenance voltage for the module. Generally, for a module with a power of 25~50W and a 48V input, it is more appropriate to choose a capacitor of about tens of microfarads. Considering the ripple factor, try to choose a capacitor with low ESR.

In order to prevent the transient high voltage of the input power from burning the power supply module, it is recommended that the user connect a transient absorption diode at the input end and use it with a fuse to ensure that the module is within a safe input voltage range.

In order to reduce common mode noise, Y capacitors can be added. Generally choose a few nanofarad high-frequency capacitors.

(2) Output overvoltage protection circuit

1. Consideration of output overvoltage

The output of the module power supply produced by Gongjun Electronics has over-voltage clamping protection, and there is basically no output over-voltage phenomenon, so there is no need to add an over-voltage protection circuit. The circuit shown in Figure 2-20 is recommended by us. It is only suitable for Overvoltage requirements and strict application circuits are provided for users' reference.

2. Consideration of output ripple and noise

In most of the circuits, the output ripple and noise of the power supply module of our Gongjun Electronics can meet the requirements. For power systems that have strict requirements on the output ripple, a differential mode filter can be added to the output to reduce the ripple. Adding a common mode filter can eliminate and reduce noise. Adding isolation capacitors (generally a few nF) between the input and output and the case can also reduce common mode noise.