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Open Collector
An open collector is a common type of output found on many integrated circuits (IC), which behaves like a switch that is either connected to ground or disconnected. Instead of outputting a signal of a specific voltage or current, the output signal is applied to the base of an internal NPN transistor whose collector is externalized (open) on a pin of the IC. The emitter of the NPN transistor is connected internally to the ground pin. If the output device is a MOSFET the output is called open drain and it functions in a similar way. For example, the I²C bus and 1-Wire bus are based on this concept. Function In the picture, the transistor base is labeled "IC output". This is a signal from the internal IC logic to the transistor. This signal controls the transistor switching. The external output is the transistor collector; the transistor forms an interface between the internal IC logic and parts external to the IC. On schematic component symbols, the open output is indicated wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt Request
In a computer, an interrupt request (or IRQ) is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead. Hardware interrupts are used to handle events such as receiving data from a modem or network card, key presses, or mouse movements. Interrupt lines are often identified by an index with the format of ''IRQ'' followed by a number. For example, on the Intel 8259 family of programmable interrupt controllers (PICs) there are eight interrupt inputs commonly referred to as ''IRQ0'' through ''IRQ7''. In x86 based computer systems that use two of these PICs, the combined set of lines are referred to as ''IRQ0'' through ''IRQ15''. Technically these lines are named ''IR0'' through ''IR7'', and the lines on the ISA bus to which they were historically attached are named ''IRQ0'' through ''IRQ15'' (although historically as the number of hardware devices increased, the total possible number of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Collector
In electronics, a common collector amplifier (also known as an emitter follower) is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a voltage buffer. In this circuit the base terminal of the transistor serves as the input, the emitter is the output, and the collector is ''common'' to both (for example, it may be tied to ground reference or a power supply rail), hence its name. The analogous field-effect transistor circuit is the common drain amplifier and the analogous tube circuit is the cathode follower. Basic circuit The circuit can be explained by viewing the transistor as being under the control of negative feedback. From this viewpoint, a common-collector stage (Fig. 1) is an amplifier with full series negative feedback. In this configuration (Fig. 2 with β = 1), the entire output voltage ''V''out is placed contrary and in series with the input voltage ''V''in. Thus the two voltages are subtracted according ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General-purpose Input/output
A general-purpose input/output (GPIO) is an uncommitted digital signal pin on an integrated circuit or electronic circuit (e.g. MCUs/ MPUs ) board which may be used as an input or output, or both, and is controllable by software. GPIOs have no predefined purpose and are unused by default. If used, the purpose and behavior of a GPIO is defined and implemented by the designer of higher assembly-level circuitry: the circuit board designer in the case of integrated circuit GPIOs, or system integrator in the case of board-level GPIOs. Integrated circuit GPIOs Integrated circuit (IC) GPIOs are implemented in a variety of ways. Some ICs provide GPIOs as a primary function whereas others include GPIOs as a convenient "accessory" to some other primary function. Examples of the former include the Intel 8255, which interfaces 24 GPIOs to a parallel communication bus, and various GPIO ''expander'' ICs, which interface GPIOs to serial communication buses such as I²C and SMBus. An example o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JEDEC
The JEDEC Solid State Technology Association is an independent semiconductor engineering trade organization and standardization body headquartered in Arlington County, Virginia, United States. JEDEC has over 300 members, including some of the world's largest computer companies. Its scope and past activities includes standardization of part numbers, defining an electrostatic discharge (ESD) standard, and leadership in the lead-free manufacturing transition. The origin of JEDEC traces back to 1944, when RMA (subsequently renamed EIA) and NEMA established the Joint Electron Tube Engineering Council (JETEC) to coordinate vacuum tube type numberings. In 1958, with the advent of semiconductor technology, the joint JETEC-activity of EIA and NEMA was renamed into Joint Electron Device Engineering Council. NEMA discontinued its involvement in 1979. In the fall of 1999, JEDEC became a separate trade association under the current name, but maintained an EIA alliance, until EIA ceased o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudo Open Drain Description
The prefix pseudo- (from Greek ψευδής, ''pseudes'', "false") is used to mark something that superficially appears to be (or behaves like) one thing, but is something else. Subject to context, ''pseudo'' may connote coincidence, imitation, intentional deception, or a combination thereof. * In scholarship and studies, pseudo-scholarship refers to material that is presented as, but is not, the product of rigorous and objective study or research. Examples: **Pseudoarchaeology ** Pseudohistory ** Pseudolinguistics *** Pseudoscientific language comparison *** Folk linguistics ** Pseudomathematics ** Pseudophilosophy ** Pseudonym ** Pseudoscience **Pseudoculture * In biology and botany, the prefix 'pseudo' is used to indicate a species with a coincidental visual similarity to another genus. For example, ''Iris pseudacorus'' is known as '''pseud''acorus' for having leaves similar to those of ''Acorus calamus''. In biology, coincidental similarity is not the same as mimicry. * In l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DDR4 SDRAM
Double Data Rate 4 Synchronous Dynamic Random-Access Memory (DDR4 SDRAM) is a type of synchronous dynamic random-access memory with a high bandwidth (" double data rate") interface. Released to the market in 2014, it is a variant of dynamic random-access memory (DRAM), of which some have been in use since the early 1970s, and a higher-speed successor to the DDR2 and DDR3 technologies. DDR4 is not compatible with any earlier type of random-access memory (RAM) due to different signaling voltage and physical interface, besides other factors. DDR4 SDRAM was released to the public market in Q2 2014, focusing on ECC memory, while the non-ECC DDR4 modules became available in Q3 2014, accompanying the launch of Haswell-E processors that require DDR4 memory. Features The primary advantages of DDR4 over its predecessor, DDR3, include higher module density and lower voltage requirements, coupled with higher data rate transfer speeds. The DDR4 standard allows for DIMMs of up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IC Power Supply Pin
IC power-supply pins denote a voltage and current supply terminals in electric, electronics engineering, and in Integrated circuit design. Integrated circuits (ICs) have at least two pins that connect to the power rails of the circuit in which they are installed. These are known as the power-supply pins. However, the labeling of the pins varies by IC family and manufacturer. The double subscript notation usually corresponds to a first letter in a given IC family (transistors) notation of the terminals (e.g. VDD supply for a drain terminal in FETs etc.). The simplest labels are V+ and V−, but internal design and historical traditions have led to a variety of other labels being used. V+ and V− may also refer to the non-inverting (+) and inverting (−) voltage inputs of ICs like op amps. For power supplies, sometimes one of the supply rails is referred to as ground (abbreviated "GND") positive and negative voltages are relative to the ground. In digital electronics, negat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operational Amplifier
An operational amplifier (often op amp or opamp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op amp produces an output potential (relative to circuit ground) that is typically 100,000 times larger than the potential difference between its input terminals. The operational amplifier traces its origin and name to analog computers, where they were used to perform mathematical operations in linear, non-linear, and frequency-dependent circuits. The popularity of the op amp as a building block in analog circuits is due to its versatility. By using negative feedback, the characteristics of an op-amp circuit, its gain, input and output impedance, bandwidth etc. are determined by external components and have little dependence on temperature coefficients or engineering tolerance in the op amp itself. Op amps are used widely in electronic devices today, including a vast array of consumer, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIA-485
RS-485, also known as TIA-485(-A) or EIA-485, is a standard defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. The standard is jointly published by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA). Digital communications networks implementing the standard can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear, multidrop bus. These characteristics make RS-485 useful in industrial control systems and similar applications. Overview RS-485 supports inexpensive local networks and multidrop communications links, using the same differential signaling over twisted pair as RS-422. It is generally accepted that RS-485 can be used with data rates up to 10 Mbit/s or, at lower speeds, distances up to . As a rule of thumb, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SCSI
Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interfaces. The SCSI standard defines command sets for specific peripheral device types; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements. The initial Parallel SCSI was most commonly used for hard disk drives and tape drives, but it can connect a wide range of other devices, including scanners and CD drives, although not all controllers can handle all devices. The ancestral SCSI standard, X3.131-1986, generally referred to as SCSI-1, was published by the X3T9 technical committee of the American National Standards Institute (ANSI) in 1986. SCSI-2 was published in August 1990 as X3.T9.2/86-109 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital-to-analog Converters
In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function. There are several DAC architectures; the suitability of a DAC for a particular application is determined by figures of merit including: resolution, maximum sampling frequency and others. Digital-to-analog conversion can degrade a signal, so a DAC should be specified that has insignificant errors in terms of the application. DACs are commonly used in music players to convert digital data streams into analog audio signals. They are also used in televisions and mobile phones to convert digital video data into analog video signals. These two applications use DACs at opposite ends of the frequency/resolution trade-off. The audio DAC is a low-frequency, high-resolution type while the video DAC is a high-frequency low- to medium-resolution type. Due to the complexity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
