Capacitor (tantalum)
Capacitor
A polarized capacitor that uses tantalum metal for its electrodes, offering high capacitance per volume and stable performance. Commonly used in power supply filtering and timing circuits.
Schematic symbol
Capacitor (polarised)
How capacitor (tantalum) appears in a circuit diagram.
Types & variants
Key specs
Capacitance
Farad (F)Charge storage capacity. Common values: 1µF to 100µF, up to 1000µF.
Voltage rating
Volt (V)Max DC voltage before breakdown. Must be > circuit operating voltage.
Tolerance
%How far the real value can stray from marked value (e.g. ±10%, ±20%).
ESR
Ohm (Ω)Equivalent Series Resistance. Lower is better for power filtering.
Leakage current
µACurrent that flows when voltage is applied. Should be very low.
Markings
Polarized! Positive lead marked with stripe/plus sign. SMD: 3-digit code (e.g. 106 = 10µF), voltage rating, and tolerance code.
Standard values
Common values: 1µF, 2.2µF, 4.7µF, 10µF, 22µF, 47µF, 100µF. Voltage ratings: 4V to 50V.
How to choose
1) Determine needed capacitance and voltage. 2) Select voltage rating > circuit max. 3) Check ESR for power apps. 4) Consider tolerance for timing circuits. 5) Observe polarity!
Pinout & package
2 leads (polarized - positive marked). Packages: Radial (through-hole), molded SMD (case codes A, B, C, D), and chip tantalum.
Example circuits
- Power supply decoupling/bypass
- Timing circuits
- Coupling between amplifier stages
- Sample-and-hold circuits
Common failures
Short-circuit from voltage spikes or reverse polarity (often catastrophic). Capacitance loss or increased ESR over time. Visible: bulging, discoloration, or leakage.
How to test
1) Discharge capacitor first! 2) Set multimeter to capacitance mode. 3) Measure with correct polarity. 4) For ESR, use ESR meter. 5) Out-of-circuit testing most reliable.
Substitutes
Ceramic capacitors (for lower values), aluminum electrolytic (for higher values/voltages). Ensure same capacitance, voltage rating, and low ESR for power apps.