What is the application of dcdc power module

In industry applications, mainly isolated power modules, the editor will explain to you belowdcdc power moduleThe role of, mainly has the following aspects:

Noise isolation: (analog circuit and digital circuit isolation, strong and weak signal isolation);

Ground loop elimination: remote signal transmission distributed power supply system.

Isolation loop, voltage conversion, protection, power conversion between different grounds, etc.

Safety isolation: strong and weak current isolation IGBT isolation drive surge isolation protection lightning isolation protection (such as isolation protection of medical electronic equipment in contact with the human body);

DC-DC power supply module input protection application circuit

fuse

Since there is no fuse inside the module, a fuse is usually used outside the module to provide safety protection to meet the requirements of international safety regulations. At ambient temperature of 25 ℃

There are:

IEC specification: rated current of the fuse=maximum steady-state input current/0.9

UL specification: rated current of the fuse=maximum steady-state input current/0.75

When the ambient temperature rises, the load-carrying capacity of the fuse will decrease, so our company recommends that the fuse specification can be 1.5 to 2.5 times the maximum steady-state input current.

Input transient overvoltage protection

For input transient overvoltage protection, a transient suppression diode or transient absorber (metal-oxide varistor) can be installed, which should be placed behind the fuse,

In front of the electrolytic capacitor.

Input capacitance

An electrolytic capacitor should be installed at the input end of the module, which reduces the power supply impedance on the one hand and makes the module work reliably; on the other hand, it can also reduce anti-serial interference.

When choosing a capacitor, in addition to considering the ripple current and voltage, an electrolytic capacitor with low ESR should also be selected.

Y capacitor

It is recommended to install a Y capacitor to reduce common mode noise. The center of the Y capacitor is connected to the module housing (FG) and connected to the system protection ground. The capacity is generally a few nanofarads (nF) to tens of

Nanofarad (nF), the withstand voltage and leakage current of the capacitor should meet the requirements of safety regulations.

Common mode inductance

It can effectively suppress common-mode interference. When selecting a common-mode inductor, the allowable current, inductance, and Q value of the inductor should be considered.