Aluminum Electrolytic Capacitor and Tantalum Electrolytic Capacitor (II)

Aluminum electrolytic capacitors and tantalum electrolytic capacitors:

The capacity of the aluminum electrolytic capacitor is relatively large, the series resistance is large, the inductance is large, and it is sensitive to temperature. It is suitable for low frequency filtering where the temperature does not change much and the operating frequency is not high (not higher than 25 kHz). Aluminum electrolytic capacitors have polarity and must be properly polarized during installation, otherwise there is a risk of explosion.

Compared with aluminum electrolytic capacitors, tantalum electrolytic capacitors have obvious advantages in series resistance, inductive reactance, and stability to temperature. However, its operating voltage is low.

Paper capacitors and polyester film capacitors:

Its volume is relatively small, the series resistance is small, and the inductive reactance value is large. It is suitable for low-frequency filtering and bypassing where the capacity is not large and the operating frequency is not high (such as below 1MHz). When using a tubular paper capacitor or a polyester film capacitor, the outer casing can be connected to the reference ground so that the outer casing can function as a shield to reduce the influence of electric field coupling.

Mica and ceramic capacitors:

The volume ratio is small, the series resistance is small, the inductance value is small, and the frequency/capacity characteristics are stable. It is suitable for high-frequency filtering, bypassing and decoupling in applications with small capacitance and high operating frequency (frequency up to 500MHz). However, such capacitors are weakly capable of withstanding transient high voltage pulses, so they cannot be simply bridged across a low resistance power line unless specifically designed.

Polystyrene capacitors:

The series resistance is small, the inductance value is small, and the capacitance is stable with respect to time, temperature and voltage. It is suitable for applications requiring high frequency stability and can be used for high frequency filtering, bypassing, and decoupling.

In terms of temperature drift, the monolith is a positive temperature enthalpy +130 or so, and the CBB is a negative temperature coefficient -230. By using the appropriate ratio in parallel, the temperature drift can be reduced to a small value.

In terms of price, tantalum capacitor is the most expensive, monolithic, CBB is cheaper, porcelain is the lowest, but there is a kind of high-frequency zero-temperature drift black point porcelain is slightly more expensive. Mica capacitor Q value is higher, the price is also slightly more expensive.