Vishay’s power resistor offers high-power dissipation and improved pulse-handling capability for hybrid and electric vehicles

By Warren Miller, contributing writer

Vishay
Intertechnology, Inc.
recently unveiled the new LTO 150, a thick-film power
resistor designed to dissipate energy and heat when charging electric or hybrid
vehicles — among other applications. The
resistor features a clip-mount TO247 package for direct mounting on a heatsink.

The LTO 150
was developed to function as the precharge or discharge resistor for the
inverters/converters and on-board chargers used in semi- or fully electric
vehicles, although it can also be employed in broader power conversion
applications, including industrial and military applications. Operating temperatures
can go as high as 175°C while resistance values range from
between 0.03 Ω to 1.3 MΩ, while its non-inductive design maintains RoHS compliance.

New resistors
may not generate as much excitement as a new battery technology, but creating an
efficient EV charging system can be just as important as the battery that it
charges. One of the most important elements of EV use, to the driver, is how
long you need to wait to “fill up” the car battery. Efficient resistors for
implementing inverters and converters can be key parts of a faster charging
system.

The LTO 150
greatly diminishes the need for external components to cool the resistor,
thereby minimizing functional size, design time, and operational costs. Compared to similar devices in TO247 packages,
the LTO 150 provides 70% more power dissipation and a 30% enhancement in energy
handling, according to the company. In
automotive-specific applications, the device dissipates 150 W at a case
temperature of 45°C while offering better
pulse-handling capability than its predecessors. The devices are AEC-Q200- and RoHS-compliant.

Samples and
larger quantities are currently available. Lead time is 8 to 12 weeks.