Infineon Technologies' Power PROFET is an ultra-low ohmic smart high-side switch family that the company aims for engineers to use in replacing electromechanical relays and fuses in power distribution and junction boxes up to 40A DC.

Removing relays, fuses in cars

A vehicle’s power architecture is restricted by the intrinsic limitations of relays and fuses. They are too bulky, often in need of replacement and some of their functionalities are limited: for instance, their switching cycle capability is only about 200,000.

Infineon claims its Power PROFET switches address these issues. The FETs offer over 1 million switching cycles and replace in a single device many components from the existing system, including relays, fuses, relay drivers, cables and connectors. This allows new mounting locations and, therefore, enables the next generation of decentralised power architectures.

“The new generations of smarter power distribution architectures will greatly benefit from the high reliability, small form factor and diagnosis capability of our new Power PROFET,” said Andreas Doll, Vice President and General Manager, Body Power Automotive at Infineon. “With the release of the ultra-low ohmic Power PROFET family we further expand our broad portfolio of high-side switches available to our customers.”

The Power PROFET switches have on-resistances as low as 1mΩ and are designed to drive high-current applications, such as power feeds of ECUs, auxiliary power outlets, PTC heaters or rear window heaters. The switches are also well-suited for applications with high switching cycles and high energy requirements such as starter relays in “start-stop” systems and electric brake vacuum pumps. Power PROFET switches offer integrated protection functions and diagnostics functionality, including short-circuit and over-temperature protection.

Infineon claims that Power PROFET switches increase energy efficiency as power losses are reduced by a factor of up to 7. They feature <2W dissipation, while conducting 30A DC. Further power management is supported through integrated current sensing and pulse-width modulation (PWM) capability. The switches also offer energy handling capability of up to 3,000mJ for single pulses and 550mJ for repetitive pulses. For most applications, this eliminates the need for a free-wheeling current recirculation path thus reducing system cost.

1 million short-circuit cycles

The switches provide protection performance of >1 million short-circuit cycles, achieving Grade A per AEC-Q100. In case of a single over-current event, a re-start strategy can be implemented via a software reset obviating the need to access or replace a part.

At the system level, Power PROFET switches simplify significantly the wire harness architecture by reducing the lengths of many wires or removing them completely and affecting system cost savings. The cost saving is based on the effective implementation of Power PROFET and on simplified vehicle production processes.

The Power PROFET family consists of 4 pin-compatible switches controlling currents from 20A to 40A DC. They share the same feature set. Only their on-state resistance RDS(ON) scales with 1mΩ, 1.5mΩ, 2mΩ or 2.5mΩ for each device.

Infineon is also offering a Power PROFET evaluation board to support design. You can download evaluation software, user’s manual, application notes and further information from

This article is sponsored by Infineon Technologies.