Rohm claims its VML0604 transistor, with dimensions of 0.6 by 0.4 by 0.36 mm, is 50% smaller than comparable products, making it the smallest in the industry. The device will target smartphones and other compact portable devices that require thin form factors.
Decreasing package dimensions place a limit on the transistor’s element size. As the element size decreases, on resistance increases dramatically, which often degrades the performance of conventional small-signal transistors.
New high-precision package and element processes, along with an optimized internal structure, reduce package size and on resistance (0.25 Ω @ VGS = 4.5 V) while improving breakdown voltage to 40 to 60 V, depending on the device. Rohm plans to expand these package developments to small-signal MOSFETs.