DC Bias Characteristics in 0805 Size Improves Performance by 27% Over Previous Model
Taiyo Yuden has put on sale the compact wire-wound power inductor BRL2012 series in 0805 size (2.0 x 1.25 x 1.0mm, height is maximum value) and BRC1608 series in 0603 size (1.6 x 0.8 x 0.8mm), optimum for the choke coils of DC-DC converters for increasingly compact, high functionality mobile devices.
These products achieve a high value of allowable DC bias current (hereafter called “DC bias characteristics”), contributing to further downsize compact mobile devices that need higher current for increasingly advanced functionality. BRL2012 achieves a 27% improvement in the DC bias characteristics over the company’s previous model.
Mass production is scheduled to start in April 2007, with a planned monthly production of 10 million units. The sample price for both series is 20 yen per unit.
Mobile phones, digital still cameras, portable music players, and other mobile devices are increasingly using switch-mode DC-DC converters for power circuits as a way to more efficiently use limited battery power. While the switch-mode DC-DC converter rapidly switches voltage on and off for highly efficient conversion of voltage, it also requires a larger number of parts, and DC-DC converters have been naturally large in size. With the faster switching frequency, the DC-DC converter parts are becoming more compact.
In addition, DC-DC converters for high-functionality mobile devices increasingly supply high current through use of faster IC clock frequencies and shifts to lower voltages. For the choke coils used in the DC-DC converters in these kinds of mobile devices, a wire-wound inductor with good DC bias characteristics is particularly suitable. However, since impedance grows higher as wire-wound inductors become more compact, leading to deterioration of DC-DC converter efficiency, maintaining good DC bias characteristics and low impedance while achieving the more compact size demanded in choke coils has been a difficult task that has proven to be a bottleneck in speeding up the switching frequency.
In response, Taiyo Yuden in September 2006 optimized the product design based on a structure that strictly excludes all wasted space, to release the BRL2518 series, 1008 size wire-wound power inductors that maintain both good DC bias characteristics and low impedance. Moreover, in expectations of demand for even more compact size in high-functionality mobile devices, Taiyo Yuden incorporated its compact wire-wound chip inductor design and development capabilities and manufacturing technologies into further refinements for the BR series. While maintaining the low impedance characteristics, Taiyo Yuden thus developed compact wire-wound power inductors with excellent DC bias characteristics achieving 850mA saturation current for the 0805 and 0603 sizes, (in both cases, 1.0ìH), which realize a high-current yet compact DC-DC converter.