Benefits of using a non-isolated DC-DC converter

The DC power requirements of electronic industry equipment usually include 24V high power output and many low power and low voltage. Traditionally, these requirements have been met with a variety of power supply architectures, depending on the amount of system power required.

For applications requiring low power (300W or less), a standard multi-output power supply is usually chosen. Twin, three, and four versions can be purchased off the shelf at a cost effective price. A variety of models with 5V, +/-12, +/-15V and 24V output combinations are available.

For medium and high power requirements, 350W to 1500W, modular or configurable power supply is usually selected. Here, high power 24V modules can be selected and other voltage combinations required can be satisfied through single or dual output modules. These made-to-order power supplies have short supply times because they are assembled using pre-assembled components. For convenience, all connections can be connected to a package with integrated fan cooling.

An alternative to medium to high power is to use a single output high power unit to provide other voltages for 24V and isolated DC-DC converters. Single, double, and triple output converters can also be purchased off-the-shelf for a variety of common voltages. Mounted as plates, they can be placed close to the load to avoid wiring and improve load regulation. For power levels greater than 100W, heat dissipation may be difficult to manage and requires the use of heat sinks or fans for cooling. Cost can also be an issue as well as product choice, as higher power converters will often cater for 48V nominal DC input.

The communications and computer industries initially used isolation converters, but their power architecture changed as FPGas required lower and lower voltages at higher currents. The use of non-isolated POL (point of load) converters is now commonplace. These devices typically offer a wide range of adjustable voltages between 0.6 and 5V, with currents up to 100A, and are designed to operate at input voltages between 3V and 14V.

The higher efficiency allows for operation at higher temperatures without airflow and without the need for additional radiators. The derating curve of the i6A allows operation at ambient temperatures of 50°C or higher without forced ventilation, similar to most AC-DC power supplies.

The lower cost is another good reason to choose a non-segregated product, with savings of up to 50%. The step-down converter topology allows a wide range of output adjustments; In the case of i6A from 3.3V to 24V. This saves additional inventory carrying costs by storing only one part, and also allows large purchases for discounts.

Note that step-down converters can only lower the input voltage and are commonly referred to as step-down converters. For example, if the input voltage is 12V, it cannot produce a 20V output. Isolated DC-DC converters can be used to produce a positive or negative output, depending on how the positive and negative terminals are connected.

This interesting power architecture is rapidly gaining popularity, appealing to those who want to reduce costs, size and energy efficiency.