What are isolated DC/DC converters? What kinds of isolated DC/DC converters are applicable? Which applications require high isolated converters? DC/DC converters are power supplies that can change one DC supply voltage into another DC voltage. In other words they act like a transformer but with constant voltage supplies instead of AC supplies.
RECOM’s product range includes CE-certified DC/DC converters with input voltages up to 160VDC. The compact 20W to 50W modules are specially designed for the extreme working conditions of railway applications and are designed to meet the stringent conditions of EN50155.
Certified rugged DC/DC converters for the railway industry
Rolling stock operation on trains subjects electronic components to extreme conditions. Voltage fluctuations, extreme temperature and continuous vibration combine to stress components and materials. The RPR-series has been specially designed for such conditions. These rugged DC/DC converters cover the power range from 20W, 30W, 40W or 50W, and are EN60950 and EN50155 compatible for railway applications. The mechanical stability for vibration exceeds the EN61373 specified 10G for 15 hours in all three axes.
The modules feature a built-in EMC filter that is EN50121-3-2 compliant and input over-voltage protection circuitry, therefore eliminating the requirement for any active external components. The RPR converters have three input voltage options that cover the EN50155 nominal voltages of 24VDC, 36VDC, 48VDC, 72VDC, 92VDC or 110VDC. Output voltages are 3.3VDC, 5VDC, 12VDC, 15VDC or 24VDC, as well as dual output voltages of ±12VDC, ±15VDC and ±24VDC. The outputs are fully protected against overload, short circuit and over voltage.
Power converters with high efficiency
All the RPR-series converters have an exceptionally high efficiency of 90%. The heat management was designed in such a way that the converters can perform at full load at ambient temperatures from -45°C to +85°C thus exceeding the EN50155 Tx rating. The maximum allowable case temperature is +120°C. If this value is exceeded for an extended period, a thermal protection circuit switches the converter off until it cools down.
The RPR series have been designed for optimum thermal management within the converters. All internal active components, such as the switching FETs and synchronous rectifiers, are mounted close to the metal casing to promote heat transfer out of the converter. The internal transformer has good thermal contact to the case top and bottom and even the pins are designed to aid thermal transfer out of the converter. A high-grade potting material (UL94-V0) is used to seal the converter against moisture. The case is made from aircraft-grade aluminum, which reduces the module weight as well as providing a six-sided EMC shield. All converters of the RPR-series are 1.5kVAC/minute isolated.
Compact DC/DC converters for railway rack systems
The specially developed RPR-series for railway applications requires far less space than comparable models. The dimension of the module is only 2in (50.8mm) x 1.5in (30.5mm) x 0.4in (11.4mm). The version with mounting baseplate facilitates fixed mounting to housing or the PCB. The version with the flat top is more compact and is suitable for mounting against a heat sink. The two case variants enable the converters to be used in most railway rack systems or to be installed onto bulkheads or behind panels.
DC/DC converters for a reliable power supply
EN50155 places high requirements on information systems and electronic components for railway applications. This also applies to DC/DC converters, which have to ensure a reliable power supply for several years. The RPR-series is specified with a MTBF of approximately 2.2 million hours. A simple power supply will be more reliable than a complicated one, so the RPR series has been designed to need very few components. The built-in protection circuitry means that the only external components required are a diode and a few capacitors to meet all of the surge, transient and ESD requirements of EN50155. The six-sided shield means that all of the conducted and radiated EMC standards can be met easily without any external filtering.
RECOM delivers this advanced RPR-series with a three-year warranty and offers competitive prices.
Sample stock and enquiries
Sample stock can be delivered by leading distributors worldwide. Detailed datasheets are available on the RECOM website, www.recom-electronic.com and the RECOM team is available to respond to your enquiries at any time.