Electrolytic capacitor conductivity of metals. In 1991 Panasonic came on the market with its "SP-Cap", called polymer aluminum electrolytic capacitors. These aluminum electrolytic capacitors with polymer electrolytes reached very low ESR values directly comparable to ceramic multilayer capacitors (MLCCs). They were still less expensive than tantalum capacitors and with their flat design for laptops and cell phones competed with tantalum chip capacitors as well. Tantalum electrolytic capacitors with PPy polymer electrolyte cathode followed three years later. In 1993 NEC introduced its SMD polymer tantalum electrolytic capacitors, called "NeoCap". In 1997 Sanyo followed with the "POSCAP" polymer tantalum chips. A new conductive polymer
Electrolytic capacitor and phase at a particular frequency. In data sheets of electrolytic capacitors only the impedance magnitude "|Z|" is specified, and simply written as ""Z"." Regarding the IEC/EN 60384-1 standard, the impedance values of electrolytic capacitors are measured and specified at 10 kHz or 100 kHz depending on the capacitance and voltage of the capacitor. Besides measuring, the impedance can be calculated using the idealized components of a capacitor's series-equivalent circuit, including an ideal capacitor "C", a resistor "ESR", and an inductance "ESL". In this case the impedance at the angular frequency "ω" is given by the geometric (complex) addition of