257LE-48-SD | DC/DC buck-boost converter 24 VDC to 48.40 VDC, 228 W

Efficient 48 V power from 12 V and 24 V systems

The 257LE-48-SD by Demke Electronic is a compact, non-isolated DC/DC converter designed to supply 48 V systems from 12 V and 24 V power sources. With a nominal input voltage of 24 VDC, it operates across a wide input voltage range of 10 to 35 VDC and provides a regulated output voltage of 48.40 VDC at up to 4.75 A. The specified output power is 228 W.

The 257LE-48-SD therefore provides an efficient interface between different battery voltages and modern 48 V power architectures. Its wide input voltage range also allows reliable operation when the supply voltage varies significantly, as is common in battery-powered and mobile systems.

Up to 98% efficiency

With an efficiency of up to 98%, the 257LE-48-SD is designed for highly efficient power conversion with very low losses. High conversion efficiency reduces heat generation and ensures that as much of the available input energy as possible reaches the 48 V load.

This is particularly beneficial in battery-powered applications, where conversion losses have a direct impact on overall system efficiency. Lower power dissipation also reduces the thermal load on the converter and simplifies integration into compact systems with limited installation space.

228 W at only approximately 360 g

High power does not necessarily require a large and heavy converter. The 257LE-48-SD delivers up to 228 W of output power while measuring only 90 × 90 × 26 mm and weighing approximately 360 g.

Its low weight is particularly notable considering its robust fully potted polyurethane construction. The potting compound protects the power electronics against demanding environmental conditions and mechanical stress while also supporting efficient heat transfer from the internal components to the housing.

The result is a high power density that is particularly valuable in applications where weight and installation space are critical without compromising robustness or available output power.

Stable 48 V output under changing operating conditions

The control system of the 257LE-48-SD is designed to maintain stable output operation across the specified input voltage range. Variations in battery voltage and connected load are regulated to provide a reliable 48 V supply for downstream equipment.

Combined CC/CV control provides both precise voltage regulation and defined current limiting. Under normal operating conditions, the converter operates in constant-voltage mode. When the current limit is reached, it transitions in a controlled manner into constant-current operation.

This characteristic is particularly useful with dynamic, capacitive or actively controlled loads and ensures predictable converter behavior even under demanding load conditions.

Designed for dynamic loads

In high-performance DC/DC converters, maximum output power alone does not determine the quality of the power supply. The response to rapid changes in load is equally important. The control system of the 257LE-48-SD has therefore been specifically designed for stable operation under dynamic conditions.

The 48 V rail remains controlled even during rapid changes in output current. The design follows our Reliability by Design philosophy, balancing control dynamics, thermal stress and semiconductor protection to achieve not only high performance but also reliable long-term operation.

Easy scalability through parallel operation

When additional output power is required, multiple 257LE-48-SD converters can be operated in parallel. Load sharing is achieved through a defined passive droop characteristic, eliminating the need for an additional load-share bus or communication link between the individual DC/DC converters.

This allows higher-power 48 V supplies to be built using a modular architecture with relatively little additional integration effort. The same principle can also be used for redundant power architectures in which multiple converters supply a common 48 V rail.

Eliminating an additional communication link reduces system complexity and removes another potential point of failure from the power architecture.

Clean power through integrated filtering

The 257LE-48-SD features integrated filtering on both the input and output side. Low ripple and low electrical noise support a clean supply for downstream electronics and simplify EMC-compatible integration of the converter into the overall system.

For sensitive electronics, control systems, communication equipment and dynamically changing loads, a low-noise power supply can help reduce the need for additional filtering and minimize electrical stress on downstream components.

Robust design for mobile and industrial systems

The 257LE-48-SD has been developed for reliable operation under demanding conditions. Its wide temperature range, fully potted construction, integrated filtering and permanent short-circuit and no-load capability support use in mobile, battery-powered and industrial systems.

The combination of high efficiency, compact dimensions, low weight, robust construction and scalable output power makes the 257LE-48-SD an efficient solution for modern 48 V power architectures.