Thanks to the ongoing improvements of Li-ion battery technology, an ever-increasing proportion of this total will be made up of cordless power tools that combine convenience and flexibility with higher degrees of safety than mains-powered alternatives. Indeed, projections by Technavio suggest that by 2021 cordless tools could represent at least 40% of the overall market.
To heighten user experience and comfort and give themselves an edge in a crowded and highly competitive sector, OEMs are looking to make their cordless power tools ever more compact and lightweight. In addition, they want to extend the time between recharges for as long as possible. Each of these factors puts pressure onto the supporting power electronics. To squeeze everything into a compact ergonomic design, decisions need to be made about key items, like the battery and the motor that will be employed.
The smaller the battery, the greater the impact will be on its charging capacity, so every effort needs to be made to eliminate sources of system power loss. Specification of brushless DC motors facilitates more compressed form factors but increased power system complexity. In addition, the elevated power densities that arise from reducing the size of such tools brings heat dissipation issues. These, in turn, could lead to operational failures. Of course, OEMs cannot afford to put the long-term reliability of their products at risk due to the damage this could do to their brand.
From battery charging to motor control, MOSFETs play a key role in the latest cordless power tools. Successful design means choosing MOSFETs that meet application requirements for delivery of high power, extended operation and compact form factors. Advances in the semiconductor processes and the related packing technology used in modern MOSFET construction are allowing new benchmarks to be set in terms of on-state resistance, gate charge and recovery charge. These help to mitigate power losses and lessen harmful heat generation. By offering improved performance parameters while maintaining industry-standard package types, such devices offer OEMs drop-in replacements that mean time and resources do not need to be allocated to redesign work.
To learn more about the latest generation of MOSFET devices available from Toshiba and the impact they are having on power tool design download the following white paper: