Multi-layer Slow Blow Fuses Help Protect Automotive Infotainment

Automotive infotainment designs must provide adequate power protection over an increasingly

broad range of voltages, currents and temperatures. While the manufacturer's primary design goal

may be to improve and expand product functionality, a good design will also focus on product

survivability across all definable environments. Many automotive-centric devices, such as navigation

systems, DVD players and Bluetooth® enabled devices, must be able to function in a harsh

environment where voltage transients and temperature extremes are common, yet unpredictable.

Infotainment devices may control multiple functions with integrated modules controlling audio, video,

communications and power distribution. These modular designs are usually predicated on form

constraints as well as cost-to-repair concerns. An intelligent power distribution design that protects each

module with a current limiting device can help improve customer satisfaction and reduce warranty costs.

High inrush currents and elevated temperatures are two of the major threats to equipment powered

by the automotive bus. When selecting a fuse for vehicle infotainment systems, the designer must

make derating considerations for operating current, pulse withstand, and application temperature.

Power-on and other system operations, such as processor speed changes, or motor start-up, may cause voltage or current spikes, resulting

in nuisance blows. Over time, repeated surges may result in fuse fatigue. Extreme temperatures can cause degradation of the circuit

protection device's performance.

Many devices, once exposed to repeated overtemperature conditions, may no longer perform to specification and may begin to draw

higher and higher currents in order to maintain functionality. With enough of these degraded components incorporated into a system

design, the inrush currents may begin to exceed even the most conservative design criteria.

Selecting a fuse with slow blow characteristics, high current carrying capability, and high pulse withstand is critical in such designs.

Read the Full Infotainment Application Note Now (pdf 120KB)