the difference between passive component and active component

2023-11-03

Passive components and active components are two fundamental types of electronic components used in circuits, each serving different functions and exhibiting distinct characteristics. Here's a breakdown of the key differences between them:

Functionality:

Passive Components: Passive components are elements that do not require an external power source to perform their basic functions. They primarily interact with the flow of electrical signals without amplifying or generating power. Examples of passive components include resistors, capacitors, inductors, and passive filters.

Active Components: Active components, on the other hand, require an external power source to operate and can amplify, control, or generate electrical signals. These components can introduce gain or perform signal processing functions. Examples of active components include transistors, operational amplifiers (op-amps), integrated circuits (ICs), and semiconductor devices like diodes.

Energy Consumption 

Passive Components: Passive components do not consume electrical power from the circuit; they dissipate or store energy without amplification. Their energy dissipation is typically in the form of heat (in resistors) or electromagnetic fields (in inductors and capacitors).

Active Components: Active components consume electrical power from the circuit to perform their functions. They require a power supply to operate and can amplify signals or perform other tasks that involve the use of energy.

Signal Amplification:

Passive Components: Passive components do not amplify signals. Instead, they can attenuate (reduce) or filter signals, change phase relationships, or store energy.

Active Components: Active components have the ability to amplify signals. They can increase the strength or magnitude of electrical signals passing through them, making them crucial for tasks such as amplification, switching, and signal processing.

Examples:

Passive Components: Resistors, capacitors, inductors, transformers, filters, and passive networks.

Active Components: Transistors (bipolar junction transistors, field-effect transistors), operational amplifiers, integrated circuits, diodes, and semiconductor devices.

In summary, passive components interact with electrical signals without requiring power and do not amplify signals, while active components require power and have the ability to amplify or manipulate signals. Both types of components play essential roles in electronic circuits, with passive components providing foundational functions and active components enabling signal processing, amplification, and control.

Understanding the difference between passive and active components is crucial for any electronics enthusiast or professional engineer, as it forms the foundation for designing and troubleshooting electronic circuits.

As the picture showing.

Active Components

An active component is an electronic component which supplies energy to a circuit.

Common examples of active components include:

1.   Voltage sources
2.   Current sources

• Generators (such as alternators and DC generators)
• All different types of transistors (such as bipolar junction transistors, MOSFETS, FETs, and JFET)
• Diodes (such as Zener diodes, photodiodes, Schottky diodes, and LEDs)

3. Voltage Sources

A voltage source is an example of an active component in a circuit. When current leaves from the positive terminal of the voltage source, energy is being supplied to the circuit. As per the definition of an active element, a battery can also be considered as an active element, as it continuously delivers energy to the circuit during discharging.

4. Current Sources

A current source is also considered an active component. The current supplied to the circuit by an ideal current source is independent of circuit voltage. As a current source is controlling the flow of charge in a circuit, it is classified as an active element.

5. Transistors

Although not as obvious as a current or voltage source – transistors are also an active circuit component. This is because transistors are able to amplify the power of a signal (see our article on transisors as an amplifier if you want to know exactly how).

Passive Components

A passive component is an electronic component which can only receive energy, which it can either dissipate, absorb or store it in an electric field or a magnetic field. Passive elements do not need any form of electrical power to operate.

As the name ‘passive’ suggests – passive devices do not provide gain or amplification. Passive components cannot amplify, oscillate, or generate an electrical signal.

Common examples of passive components include:

1. Resistors
2. Inductors
3. Capacitors
4. Transformers

Resistors

A resistor is taken as a passive element since it can not deliver any energy to a circuit. Instead resistors can only receive energy which they can dissipate as heat as long as current flows through it.

Inductors

An inductor is also considered as passive element of circuit, because it can store energy in it as a magnetic field, and can deliver that energy to the circuit, but not in continuous basis. The energy absorbing and delivering capacity of an inductor is limited and transient in nature. That is why an inductor is taken as a passive element of a circuit.

Capacitors

A capacitor is considered as a passive element because it can store energy in it as electricfield. The energy dealing capacity of a capacitor is limited and transient – it is not actually supplying energy, it is storing it for later use.

As such it is not considered an active component since no energy is being supplied or amplified.

Transformers

A transformer is also a passive electronic component. Although this can seem surprising since transformers are often used to raise voltage levels – remember that power is kept constant.

When transformers step up (or step down) voltage, power and energy remain the same on the primary and secondary side. As energy is not actually being amplified – a transformer is classified as a passive element.

And Hongda Capacitors are main producing the passive components as below:

1. Tantalum capacitors

2. SMD Electrolytic Capacitors

3. Super Capacitors

4. Inductors and beads

5. MLCC & H Q MLCC

Let us introduce you to our top-selling passive components:

1. Tantalum Capacitors: We provide reliable and efficient tantalum capacitors for various applications. These capacitors are known for their excellent stability, high reliability, and low leakage current.

2. SMD Electrolytic Capacitors: Our SMD electrolytic capacitors are designed to provide superior performance and durability. They are suitable for applications where space is a constraint and demanding operating conditions are encountered.

3. Super Capacitors: Enhance your energy storage solutions with our super capacitors. These capacitors deliver high power density, longer life cycle, and quick charge-discharge capabilities.

4. Inductors and Beads: Hongda Capacitors offers a wide range of inductors and beads that are essential for effective filtering and energy storage solutions. Our products are known for their high inductance, low resistance, and excellent performance.

5. MLCC & High-Q MLCC: We provide a comprehensive range of multilayer ceramic capacitors (MLCC) and high-Q MLCCs. These offer exceptional capacitance stability, low self-inductance, and high Q-factor, ensuring optimal performance in various applications.

At Hongda Capacitors, we prioritize delivering top-notch quality components that meet industry standards and exceed customer expectations. Our dedicated team of experts ensures rigorous quality control at every stage, resulting in reliable and durable products.

To explore our full range of passive components and learn more about their specifications, please visit our website: https://hongdacap.com.hk 

Our friendly customer support team is also available to assist you with any queries or requirements.