High temperature lead type capacitors suit automotive applications

Murata Power Solutions has developed a capacitor that can withstand the extreme temperatures experienced by equipment located in environments such as the engine compartment of an automobile.

Intended to maximise fuel efficiency, a DC motor drive is used to optimise the control of the power train control system and a capacitor is used to suppress the electrical noise generated by this DC motor. This control equipment tends to be mounted in an extreme environment, where temperatures can approach 200°C for short periods of time. Consequently, a high degree of durability is needed for a capacitor deployed in this environment.

Featuring an innovative heat resistant resin coating around a highly heat resistant multilayer ceramic capacitor, Murata’s RHS capacitors can be used at temperatures up to 200°C and as low as -55°C.

The capacitors comply with AEC-Q200 and their lead wires can be soldered or crimped to position them close to a noise-generating source for optimum performance and effectiveness.The RHS capacitors also pass the extreme surge test of the ISO7637-2 standard.

According to the company, capacitance values from 10 pF to 0.01uF will be available, and the line-up initially includes 200V DC and 500V DC rated products, with the voltage range being expanded during 2017. At temperatures above 150°C, voltage derating is applied, so for example, a 500V rated capacitor is rated at 125V when used at 200°C.

Determined by the combination of rated voltage and capacitance value, the capacitors measure 4.0 × 3.5mm or 5.5 × 4.0mm, with lead centres being 2.5 or 5.0mm as appropriate.

Full production of the RHS capacitors begins in May 2017 and Murata expects to expand and diversify sales of the products for equipment mounted in a variety of high temperature environments such as engine rooms.