How to choose a high reliability DC-DC module power supply?

Time：2025-03-15 11:30:47 Read：162

DC-DC module power supplies are increasingly being used in industries such as communication, industrial automation, power control, rail transit, mining, and military. Modular design can effectively simplify customers' circuit design, improve system reliability and maintenance efficiency. So, how to improve the reliability of power systems based on DC-DC modules? This article provides a brief analysis and discussion on this topic.

1. Why do we need DC-DC module power supply?

DC-DC isolation module power supply is mainly used in distributed power systems to achieve isolation, noise reduction, voltage conversion, voltage stabilization, and protection functions for the power system. The function of using DC-DC isolation module power supply is as follows:

First, the module power supply adopts the isolated design, which can effectively isolate the impact of common mode interference from the primary side equipment on the system, so that the load can work stably.

Secondly, different loads require different supply voltages, for example, control ICs require 5V, 3.3V, 1.8V, etc; The operational amplifier used for signal acquisition requires ± 15V; Relays require 12V and 24V; The bus voltage is mostly 24V, so voltage conversion is required.

Thirdly, there will be line loss in the long-distance transmission of bus voltage, so the voltage is relatively low when it reaches the PCB board level. However, the load requires a stable voltage, so a wide voltage input and a stable voltage output are needed.

Fourthly, the power supply needs to protect the system's load and itself from damage in abnormal situations.

2. How to choose a high reliability DC-DC module power supply?

Adopting a mature power topology

The design of the power module should preferably use mature power topologies. For example, the Royer circuit is selected for the 1W-2W constant voltage input DC-DC power module, while the wide voltage input series selects the Flyback topology and some choose the Forward topology.

High efficiency within the full load range

High efficiency means lower power loss and lower temperature rise, which can effectively improve reliability. In practical applications, power supplies will choose a certain degree of derating design, especially in today's world where the power consumption of load ICs is decreasing. Most of the time, power supplies may operate under light load conditions. Therefore, high efficiency within the full load range is a crucial parameter for the reliability of power systems, but it is often overlooked by power supply manufacturers. Most manufacturers tend to achieve high full load efficiency in order to attract customers with the parameters in their technical manuals, but the efficiency is lower under 5% to 50% load conditions.

Taking the 15WDC-DC module power supply VRB2412LD-15WR2 as an example, the efficiency of VRB2412LD-15WR2 under light load of 10% at rated voltage 24V input is 15% higher than that of mainstream peers, as shown in Figure 1 and Figure 2.

By improving efficiency, the temperature rise of the product casing can also be effectively reduced. VRB2412LD-15WR2 has a 13.8 ℃ lower temperature rise during actual load operation.