Audio ICs

High-efficiency MOSFET designed for switching in small, thin devices

31 January 2023

ROHM Semiconductor has developed a compact, high-efficiency 20 V N-channel metal-oxide semiconductor field-effect transistor (MOSFET) optimized for switching in small, thin devices, including smartphones and wearables such as wireless earbuds and other hearable equipment.

The increasing sophistication and power requirements of compact devices have resulted in larger batteries that reduce the space available for mounting components. At the same time, there is a limit to the size of the battery, so to ensure more efficient use of battery power the power loss of mounted components mustSource: ROHM SemiconductorSource: ROHM Semiconductor be minimized.

To meet this need, the development of MOSFETs in wafer-level chip-size packages (WLCSP) that contribute to greater miniaturization while maintaining the necessary characteristics is becoming mainstream in the industry. ROHM leverages its strengths as an IC manufacturer to significantly reduce wiring resistance (which has increased with conventional discrete processes). The result is a compact power MOSFET that delivers low power loss.

The RA1C030LD is offered in the DSN1006-3 WLCSP (1.0 mm × 0.6 mm) that takes advantage of ROHM’s proprietary IC process to achieve low power dissipation together with greater miniaturization. In terms of the figure of merit that expresses the relationship between conduction and switching losses (ON-resistance × Qgd), an industry-leading value has been achieved that is 20% lower than standard package products in the same package (1.0 mm × 0.6 mm or smaller), contributing to a significantly smaller board area along with higher efficiency in a variety of compact devices.

The unique package structure provides insulated protection for the side walls (unlike standard products in the same package with no protection). This reduces the risk of shorts due to contact between components in compact devices that must resort to high density mounting due to space constraints, contributing to safer operation.

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