The advantages of combining low ESR polymer cathode systems with a tantalum anode are well know. The use of a tantalum anode yields one of the highest volumetrically efficient capacitor solutions in the world. For those seeking to maximize board space or minimize height, Polymer Tantalum capacitors are the go-to capacitor. By replacing the MnO2 cathode system used on traditional tantalum capacitors with polymer, dramatic reductions in ESR are achieved which result in significant improvements in capacitance retention at frequencies up to 1MHz. Newer construction features, such as low ESL designs, offer further advantage in high frequency applications, where they can be used to replace a number of MLCC’s for CPU decoupling. While some still associate all tantalum capacitors with older traditional tantalum, which exhibit much higher ESR and ignition failures, most designers understand that polymer type tantalum capacitors have low ESR and a benign failure mode. In addition, the improvements in voltage derating also allow for significant improvements in cost and space savings compared to traditional tantalum capacitors.