tantalum electrolytic capacitors are roughly comparable. Electrical characteristics Series-equivalent circuit Tantalum electrolytic capacitors as discrete components are not ideal capacitors, as they have losses and parasitic inductive parts. All properties can be defined and specified by a series equivalent circuit composed of an idealized capacitance and additional electrical components which model all losses and inductive parameters of a capacitor. In this series-equivalent circuit the electrical characteristics are defined by: C, the capacitance of the capacitor Rleak, the resistance representing the leakage current of the capacitor RESR, the equivalent series resistance which summarizes all ohmic losses of the capacitor, usually abbreviated as "ESR" LESL, the equivalent series inductance which is the effective self-inductance of the capacitor, usually abbreviated as "ESL". Using a series equivalent circuit rather than a parallel equivalent circuit is specified by IEC/EN 60384-1. Capacitance standard values and tolerances The electrical characteristics of tantalum electrolytic capacitors depend on the structure of the anode and the electrolyte used. This influences the capacitance value of tantalum capacitors, which depend on operating frequency and temperature. The basic unit of electrolytic capacitors capacitance is microfarad (μF). The capacitance value specified in the data sheets of the manufacturers is called rated capacitance CR or nominal capacitance CN and is the value for which the capacitor has been designed. Standardized measuring condition for electrolytic capacitors is an AC measuring method with a frequency of 100 to 120 Hz. Electrolytic capacitors differ from other capacitor types, whose capacitances are typically measured at 1 kHz or higher. For tantalum capacitors a DC bias voltage of 1.1 to 1.5 V for types with a rated voltage of ≤2.5 V or 2.1 to 2.5 V for types with a rated voltage of >2.5 V may be applied during the measurement to avoid reverse voltage. The percentage of allowed deviation of the measured capacitance from the rated value is called capacitance tolerance. Electrolytic capacitors are available in different tolerance series classifications, whose values are specified in the E series specified in IEC 60063. For abbreviated marking in tight spaces, a letter code for each tolerance is specified in IEC 60062. rated capacitance, E3 series, tolerance ±20%, letter code "M" rated capacitance, E6 series, tolerance ±20%, letter code "M" rated capacitance, E12 series, tolerance ±10%, letter code "K" The required capacitance tolerance is determined by the particular application. Electrolytic capacitors, which are often used for filtering and bypassing capacitors don't have