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Active electronic parts are components that require a power source to operate and can control or amplify electrical signals. These parts typically use semiconductor materials, such as silicon, to manipulate the flow of electricity.
Examples of active electronic parts include:
Transistors
These are semiconductor devices that can amplify or switch electronic signals. They are used in a wide range of electronic circuits, including amplifiers, oscillators, and power controllers.
Transistors are semiconductor devices used to amplify or switch electronic signals and electrical power. They are one of the basic building blocks of modern electronic devices and are found in almost all electronic devices. In a Printed Circuit Board (PCB), transistors play critical roles in various circuit functions such as signal amplification, regulation, switching, signal modulation, and many others.
Transistors have three layers of semiconductor material and two pn junctions, hence they are sometimes referred to as a "double junction" device. The three parts of a transistor are the emitter, the base, and the collector.
There are two main types of transistors:
Bipolar Junction Transistors (BJTs): BJTs use both electron and hole charge carriers and are known for their amplification properties. They come in two types, NPN and PNP, which are distinguished by the direction of the current flow when in operation.
Field Effect Transistors (FETs): FETs control the electrical behavior of a device using an electric field. FETs come in many forms including Junction Gate Field-Effect Transistors (JFETs) and Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs). They are widely used in applications like signal amplification and switching.
Transistors, like other electronic components, can be either through-hole or surface mount (SMD) and come in a variety of packages. The type of transistor and its specifications are typically printed on the body of the component, though some smaller SMD transistors might not have this due to their size.
When designing a PCB, it's important to consider the specifications of the transistor, including its maximum current, voltage ratings, gain, frequency response, and power dissipation. These parameters will depend on the application the transistor is being used for.
Diodes
These are components that allow current to flow in one direction while blocking it in the other. They are used in electronic circuits as rectifiers, voltage regulators, and signal demodulators.
Diodes are semiconductor devices used in electronic circuits that allow current to flow in one direction only. They have two terminals, an anode and a cathode. Current can flow from the anode to the cathode, but not in the other direction.
Diodes come in many forms and are used for a wide range of applications in a Printed Circuit Board (PCB). Here are some common types of diodes:
Rectifier Diodes: These are the most basic type of diode and are often used for converting alternating current (AC) to direct current (DC), a process known as rectification.
Schottky Diodes: These diodes have a lower forward voltage drop than regular diodes, which means they waste less energy. They are often used in power supply circuits.
Zener Diodes: These diodes can be designed to allow current to flow in the reverse direction when a specific set voltage (the Zener voltage) is reached. They're often used for voltage regulation.
Light Emitting Diodes (LEDs): These diodes emit light when current passes through them and are used for indication and lighting purposes.
Photodiodes: These diodes generate a current when they are exposed to light. They're used in various light sensing applications.
Diodes can come in both through-hole and surface-mount (SMD) varieties. The orientation of a diode when it's installed on a PCB is crucial, as installing it backwards will prevent the circuit from functioning properly. On schematics and on the diode itself, the cathode is usually marked with a line.
In terms of identifying diodes, the specific type and specifications of a diode are typically indicated by a printed code on the component's body. However, because of their small size, SMD diodes might not always have this code printed on them. Instead, you may need to refer to the manufacturer's datasheet or the PCB's bill of materials to identify them.
Integrated circuits (ICs)
These are miniaturized electronic circuits that can perform multiple functions. They are used in a wide range of electronic devices, including computers, smartphones, and medical equipment.
Integrated Circuits (ICs) are complex assemblies of transistors, diodes, resistors, and capacitors built onto a single piece of silicon, often referred to as a chip. These chips are encapsulated in a package that is then mounted onto a Printed Circuit Board (PCB). ICs are used to perform a wide range of functions in electronic devices.
ICs come in many different types and are used for a wide range of applications on a PCB, including:
Microprocessors and Microcontrollers: These are complex ICs that can perform computations and execute instructions. They are used as the brains of many types of electronic devices, from computers and smartphones to smaller devices like digital watches and microwave ovens.
Memory Chips: These ICs store data. Types of memory chips include RAM (Random Access Memory), ROM (Read Only Memory), and flash memory.
Analog ICs: These ICs process analog signals and can function as amplifiers, filters, and oscillators. Examples include operational amplifiers (op-amps) and voltage regulators.
Digital ICs: These ICs handle digital signals and include logic gates, flip-flops, counters, and shift registers.
Mixed Signal ICs: These ICs contain both analog and digital circuits. They are used in devices like smartphones, where they might handle both the digital processing of data and the analog processing of audio signals.
ICs can be either through-hole or surface mount. The specifications for an IC are usually found in its datasheet, which can often be found online. The datasheet will provide important details about the IC's function, pin configuration, recommended operating conditions, and other specifications.
ICs can come in a variety of packages, including Dual In-line Package (DIP), Small Outline IC (SOIC), Quad Flat Package (QFP), and Ball Grid Array (BGA), among others.
Selecting the correct IC for your application and ensuring that it is correctly implemented in your circuit design is a key aspect of PCB design. It's also important to ensure that the IC is correctly soldered to the PCB and that any necessary heat sinking or cooling is provided, as ICs can generate significant amounts of heat during operation.
Microcontrollers
These are specialized ICs that can control the operation of electronic systems. They are used in a wide range of applications, including automotive, industrial, and consumer electronics.
Microcontrollers are a type of integrated circuit (IC) that contain a processor core, memory, and programmable input/output peripherals. Essentially, they are a computer on a single chip designed to control electronic devices.
Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, remote controls, office machines, appliances, power tools, toys, and other embedded systems. They are the "brains" behind many smart devices and are ubiquitous in the modern world.
Most microcontrollers are designed to execute complex digital instructions for specific tasks. A single microcontroller can contain a processor, memory (both RAM and ROM), and input/output (I/O) interfaces for connecting with other components or devices.
Different microcontrollers offer different sets of peripherals like digital I/O pins, analog-to-digital converters (ADCs), digital-to-analog converters (DACs), UARTs (serial ports), I2C or SPI interfaces, pulse-width modulation (PWM) capabilities, and even built-in Wi-Fi or Bluetooth in some cases.
Microcontrollers are programmable, which means that they can be loaded with code that determines how they operate. This code can be written in a variety of programming languages, including assembly language, C, C++, and in some cases, higher-level languages like Python or JavaScript. The code is typically written on a separate computer, then loaded onto the microcontroller using a programmer or a serial interface.
Microcontrollers come in various packages, from traditional through-hole Dual In-line Package (DIP) to various Surface Mount Technology (SMT) packages like Quad Flat Package (QFP), Ball Grid Array (BGA), and many others.
Popular families of microcontrollers include the PIC series from Microchip, the AVR series from Atmel (including the ATmega series used in Arduino boards), the MSP430 series from Texas Instruments, and the ARM Cortex series from ARM Holdings, among others.
When designing with microcontrollers, it's crucial to consider factors such as processing power, memory size, power consumption, availability of needed peripherals, cost, and the availability of software tools and libraries to support development.
Operational amplifiers (op-amps)
These are high-gain voltage amplifiers that can be used to amplify and manipulate electronic signals. They are used in a wide range of electronic circuits, including filters, oscillators, and power controllers.
Operational amplifiers, often abbreviated as op-amps, are a type of integrated circuit (IC) that can amplify voltage. They are one of the most common types of ICs used in analog electronics and can be used in a wide variety of electronic devices.
Op-amps have two input pins and one output pin. The two input pins are labeled as the inverting input (usually denoted with a minus sign) and the non-inverting input (usually denoted with a plus sign). The output voltage of the op-amp is a multiplication of the difference between the voltages applied to the two input pins and the gain of the op-amp.
Op-amps are versatile devices and can be used in a wide variety of circuits, including amplifiers, filters, comparators, and oscillators, among others. The specific function of an op-amp in a circuit depends on how the circuit is designed.
There are many different types of op-amps, each with its own specifications and characteristics. Some are designed for general use, while others are designed for specific applications, such as audio amplification, precision measurements, or high-speed signal processing. The specifications of an op-amp, including its gain, bandwidth, noise performance, and power consumption, will vary depending on its design.
Op-amps can be either through-hole or surface-mount, and they come in a variety of packages, including Dual In-Line Package (DIP), Small Outline Integrated Circuit (SOIC), and many others.
When designing a circuit that uses an op-amp, it's important to select an op-amp that meets the requirements of the circuit in terms of its specifications. It's also important to design the circuit correctly to ensure that the op-amp operates in its linear region (where it can accurately amplify signals), unless it's being used in a non-linear application such as a comparator or an oscillator.
Overall, active electronic parts play a crucial role in modern electronic devices and equipment, and their correct selection and integration are critical to the performance and reliability of electronic systems.