Fairchild Semiconductor's Global Power Resource Design Centre in Germany recently completed design work for a ballast that uses SEPIC (single-ended primary inductance converter) topology. The design, ideal for low voltage dc-dc applications such as automobile headlights, will enable automobile manufacturers to meet proposed European daytime headlight safety regulations.
The ballast designs offer a range of options, including optimising factors like EMI and efficiency, and are highly variable in terms of input and output voltage as well as output power. Plans being discussed by the European Commission to cut the number of road accidents will probably lead to the mandatory use of car headlights during the daytime in the European Union.
Today's automobiles increasingly use high-brightness LEDs of up to 1W of power. However, daytime headlights typically require five to seven LEDs to comply with the expected new standard. Ideally, these LEDs should be connected in series to ensure identical current and, therefore, the brightness of each device. SEPIC topology can transform voltages up as well as down. While SEPIC topology is ideal for dc-dc applications, it is also a good choice in nonisolated low-power ac-dc applications, such as power supplies for industrial controls and white goods. This topology achieves an efficiency of about 80%.
The Global Power Resource centre in Fuerstenfeldbruck, has expertise and equipment targeted to provide power design solutions for electronic applications in the principal European end markets—industrial, consumer, and automotive.
With significant power design experience, the centre is able to turn around designs in as little as two weeks. It provides customers with fully engineered solutions, including evaluation boards; detailed reports including information for billsofmaterials (BOMs) and turnkey designs (e.g. CAD files that can be incorporated into customers' designs); and application notes. It is one of seven such centres operated worldwide by Fairchild.