The performance of every capacitor is susceptible to ambient temperature, but aluminum electrolytic capacitors are more susceptible than most.
For this reason, aluminum electrolytic capacitors are designed and shipped with specific upper and lower operating temperature limits; exceeding the upper temperature limit will result in early failure of the device, while exceeding the lower limit will result in impedance and dissipation factor figures exceeding a specified threshold limit.
Advances in processing and manufacturing technologies has resulted in an increase in the upper temperature limits that can now be attained.
The tables below provides an outline of the operating temperature ranges that are now available to the design engineer. For the sake of clarity, we have somewhat arbitrarily divided the ranges into “Standard”, “High Temperature” and “Ultra High Temperature”.
Standard Temperature Aluminum Electrolytic Capacitors
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These “standard” temperature ratings are suitable for general commercial and industrial applications, and many 105°C rated aluminum electrolytic capacitors are also suitable for automotive passenger compartment applications.
High Temperature Aluminum Electrolytic Capacitors
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These “high temperature” aluminum electrolytic capacitors are suitable for automotive applications, including many under-the-hood applications, as well as high temperature industrial applications.
Ultra High Temperature Aluminum Electrolytic Capacitors
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These “ultra high temperature” aluminum electrolytic capacitors are suitable for all automotive applications, high temperature industrial applications, some defence applications and the 175°C rated device from Cornell Dubilier is also rated for down hole applications.
A manufacturer’s data sheet will always specify the operating temperature range of the device, usually towards the top of the ratings tables.
The Capacitor Faks data sheet search engine allows you to search for aluminum capacitor data sheets by operating temperature range. Simply select the By Dielectric > Aluminum > Aluminum Electrolytic menu items from the home page of the app and then select the operating temperature range you require from the drop-down by using the Add filters button.
Aluminum electrolytic capacitors for photo flash applications will generally fall outside of these temperature ranges; they typically have reduced high temperature limits e..g +65°C.