The KEMET T550 Polymer Hermetic Seal (PHS) Series is a capacitor with a Ta anode and Ta2O5 dielectric. A conductive organic polymer replaces the traditionally used MnO2 or wet electrolyte as the cathode plate of the capacitor. This results in very low ESR and improved capacitance retention at high frequency and low temperature. The T550 PHS Series also exhibits a benign failure mode which eliminates the case breach that can occur in wet tantalum types. Additionally, this part may be operated at voltages up to 80% of rated voltage with equivalent or better reliability than traditional MnO2 or wet tantalum capacitors operated at 50% of rated voltage. T550 PHS Series also offers higher ripple current handling capability and a lower ESR range than wet tantalums. With reduced ESR and enhanced capacitance retention at higher frequencies and low temperatures, the T550 PHS Series provides the highest total capacitance and the most economical solution for high power applications, all within an approximately 25% lighter package than the equivalent wet tantalum capacitor.