New MOSFET offers bi-directional power within USB applications

Toshiba Electronics Europe GmbH has released its first 30V N-channel common-drain MOSFET. The new SSM10N961L device provides low-loss operation and is particularly intended for usage within devices with USB interfaces. Also, it may be utilised for protecting battery packs within mobile applications.

With the ubiquity of USB interfaces, many components and devices have been created to support USB standards. The USB PD standard supports higher power levels from 15W (5V/3A) to a maximum of 240W (48V/5A) and permits swapping the power supply and receiving side. This needs devices with USB charging to support bi-directional power, which is the use case for which the new MOSFET has been designed.

Until now, the company's N-channel common-drain MOSFETs have been 12V products mainly intended to protect Li-ion battery packs within smartphones. The newly released 30V product can be employed for applications demanding voltages higher than 12V, such as load switching for power lines of USB charging devices and the protection of Li-ion battery packs for battery-powered appliances.

The device combines two N-channels in a common drain configuration, which is the feature that permits bi-directional operation. The source-source breakdown voltage (V(BR)SSS) is 30V for higher voltage applications like laptops and tablets. The source-source on-resistance (RSS(ON)) is typically 9.9mOhm to reduce application losses.

When mounted on an 18µm, 407mm2 Cu pad, the device's current rating is 9A. If the pad size and thickness increase to 70µm and 687.5mm2, the current rating increases to 14A.

Despite the power handling capability of the device, it is housed in a small thin package (TCSPAG-341501) measuring just 3.37mm×1.47mm x 0.11mm, thereby allowing for high-density solutions to be developed.

By combining the new device with a TCK42xG driver IC, it is possible to form a load-switching circuit with a backflow prevention function or a power multiplexer circuit that can switch operations between MBB and BBM.

The company has released a Power Multiplexer Circuit as a reference design based upon this combination of products. The company verified the circuit's operation, providing designers confidence that it will simplify the design process and shorten timescales.