A polypropylene capacitor is a kind of capacitor with a very stable electric capacity. It is often used in applications requiring very precise capacitance and can replace most polyphenylene or mica capacitors.

Polypropylene capacitor is also called CBB capacitor. The capacitance is 10p--10μand the rated voltage is 63-2000V. It can replace most of the polyphenylene or mica capacitors for the circuit with high requirements. Its performance is similar to polyphenylene but smaller in size and slightly less stable.

Features of Polypropylene capacitor

1 Non-polarity, high insulation impedance, excellent frequency characteristics, and very small dielectric loss.

2 High dielectric constant, small volume, large capacity, and relatively good stability.

3 Small dielectric loss, high insulation resistance, but large temperature coefficient.

Roles of Polypropylene capacitor

In the circuit board, CBB (Polypropylene) capacitors are basically essential. Many people are not clear what is the use of CBB capacitors?

The film capacitor belongs to the most commonly used type of capacitor. Its insulation impedance is particularly high. It has a wide frequency response and has no polarity, so the film capacitor is often used in integrated circuit boards, analog circuits, and other circuits. In the actual application, the role of polypropylene capacitors is as follows.

Role 1: Suppress electromagnetic interference from the power supply.

It is used in the power electronic circuit. The film capacitor is used to buffer and clamp the power current, resonant bypass, and suppress the power supply electromagnetic interference, etc.

Role 2: Impedance reduction.

When the film capacitor is used as a bypass, it mainly serves to reduce the impedance of the DC bus and absorb the ripple current from the load, so as to effectively suppress the fluctuation of the DC bus voltage due to sudden changes in the load. When the device is used in a resonant converter, it can perform the resonant function together with the inductor.

Classification of Polypropylene capacitor

CBB19 metalized polypropylene film round axial capacitor

Polypropylene capacitor CBB19

Features: metalized polypropylene film is used as dielectric and electrode, and it is covered with flame-retardant tape and sealed with epoxy resin, which has excellent electrical performance, good reliability, high-temperature resistance, small volume, large capacity, etc. and good self-healing performance.

Use: Applicable to instruments, meters, household appliances, and other AC and DC circuits, widely used in audio system crossover lines.

CBB20 metalized polypropylene film flat axial capacitor

Polypropylene capacitor CBB20

Features: metalized polypropylene film is used as medium and electrode, wrapped with flame-retardant tape and sealed with epoxy resin, with excellent conductivity, high reliability, high-temperature resistance, small volume, large capacity, and good self-healing performance.

Use: Applicable to instruments, meters and household appliances, and other AC and DC circuits, widely used in audio system crossover lines.

CBB22 metalized polypropylene film DC capacitor

Polypropylene capacitor CBB22

Features: metalized polypropylene film as medium and electrode, encapsulated with flame-retardant insulating material, one-way lead, with an outer package, epoxy resin seal, with excellent electrical properties, good reliability, small loss, and good self-healing properties.

Uses: Widely used in instruments, meters, TV sets, and household electrical circuits for DC pulsation, pulse, and AC voltage reduction, especially for various types of energy-saving lamps and electronic rectifiers.

CBB60 AC motor capacitor

Polypropylene capacitor CBB60

Features and Uses: CBB60 AC motor capacitor with metallized polypropylene film has the characteristics of small volume, lightweight, low price, low loss, and good self-healing effect, etc. It is suitable for the starting and running of a one-way motor powered by an AC power supply with a frequency of 50HZ (60 HZ).

CBB61 AC motor capacitor

Polypropylene capacitor CBB61

Features and Uses: CBB61 type metalized polypropylene film capacitor for AC motor has the characteristics of small size, lightweight, low price, small loss, and good self-healing effect, etc. It is commonly used in the starting and running of a one-way motor powered by an AC power supply with a frequency of 50 HZ (60 HZ).

CBB81(PPS) metalized polypropylene high-voltage capacitor

Polypropylene capacitor CBB81

Features: With metalized polypropylene film in series structure type, it can resist high voltage and high current shock, with small loss, excellent electrical performance, high reliability, and self-healing performance.

Uses: Widely used in instruments, meters, televisions, and household appliances lines, can be used for DC pulsation and AC voltage reduction, especially for various types of electronic rectifiers and energy-saving lamps lines, but also all types of contactor contacts of high-voltage potential absorption lines.

* Utmel has a huge stock of capacitors including CBB/Polypropylene capacitors. For more details, check film capacitors here or send us RFQ. 

Working Principle of Polypropylene capacitor

CBB (Polypropylene) capacitor advantages: Non-polarity, high insulation impedance, excellent frequency characteristics (wide frequency response), and very small dielectric loss. Because of these advantages, Polypropylene film capacitors are used in a large number of analog circuits. Especially in the signal interconnection part, it is necessary to use capacitors with good frequency characteristics and very low dielectric loss to ensure that the signal is transmitted without too much distortion. Its high dielectric constant, small size, large capacity, and good stability make it suitable for bypass capacitors. With the low dielectric loss, high insulation resistance, but large temperature coefficient, the polystyrene film capacitor can be used in high-frequency circuits.

Applications of Polypropylene capacitor

CBB capacitors are generally used in: high-frequency pulse occasions, AC occasions, high stability timing occasions, temperature compensation circuits, switching power supply systems and color TV industry, instrumentation, TV sets and household appliances, electronic rectifiers, high-voltage potential absorption lines of various contactor contacts and lighting LED circuits, filtering, bypassing, coupling and other circuits. The following are five applications of CBB capacitors commonly used.

1 Filter circuit

When CBB capacitors are used in filtering circuits, it is necessary to fully understand several parameters such as DC voltage, ripple voltage, and ripple current of the circuit, so as to choose the right capacitor.

2 Motor start

The Polypropylene capacitor has good self-healing performance, long service life, high proportional characteristics, adopts electric grade polypropylene film as a medium, zinc-aluminum metalized layer as the electrode, high-quality engineering plastic shell, flame-retardant epoxy resin potting, PVC electronic wire lead, strong versatility, and flexible assembly. It is widely used in electric motors, electric fans, air conditioners, washing machines, generators, blowers, and other electrical appliances for starting or running. The diagram below shows the starting circuit of a single-phase motor with a CBB61 capacitor.

Schematic diagram of single-phase motor starting circuit

3 Interference suppression

In terms of power supply suppression interference, this kind of capacitor generally uses more X2 amperometric capacitors and Y1 amperometric capacitors.

4 Resistance buck

The resistive buck voltage uses fewer components. Most of the resistive buck voltage uses inline adjustable CBB capacitors. Its advantage is that it can be used in harsh working environments and has good stability, but not suitable for small volume occasions. Resistive buck circuit is used in many LED lighting industries, the home appliance industry, and other fields. If the power supply uses capacitive buck, then the capacitor becomes the main key component, so the selection of capacitors in this circuit and the requirements are very high.

5 Signal circuit  　　

The CBB capacitor is applied to signal circuits to act as a coupling. For example, there is a self-contained bias resistor at the emitter of a transistor amplifier. It also causes a voltage drop of the signal to be fed back to the input forming an input-output signal coupling. This resistor is the component that generates the coupling. If a capacitor is connected in parallel to both ends of this resistor, the coupling effect of the resistor is reduced due to the smaller impedance of the capacitor to the AC signal of appropriate capacity.