Bel Power Solutions IBX15 boost converter is designed as a step-up converter in order to increase the input voltage V-I to the regulated boost voltage VoBr.
When V-I exceeds VoBr, the output voltage follows V-I. The resulting voltage is in the range of VoBr to V-I max, which is suitable for adequate DC/DC converters, including 20IMX15 or 24IMX70 for 12IBX15-25 and 110IMY15 or 110IMY70 for 24/36IBX15-50. The IBX15 converters have no input-to-output isolation; isolation is provided by the DC/DC converters connected to the output.
The inrush current is not limited, but the output capacitor and the input capacitors of the connected DC/DC converters are relatively small.
The switching frequency is approximately 2, 200 kHz (interleaved). A current-limiting circuit protects the main FETs from overload. However, the output is not short-circuit proof. The logic is biased by an auxiliary converter with a switching frequency of approximately 350 kHz. The boost voltage can be adjusted to a higher level. This allows, together with an external storage capacitor Chu, the realization of an interruption time requested by the railway-standard EN 50155. No other components are needed.