Glossary
Henry(ries): The unit of inductance.
A circuit diagram which resembles the letter "H." The load is the horizontal line, connected between two pairs of intersecting lines. It is very common in DC motor-drive applications where switches are used in the "vertical" branches of the "H" to control
Data transmission over a circuit capable of transmitting in either direction, but not simultaneously.
An ADC architecture which uses a bank of comparators first to digitize the upper half bits, then uses a digital-to-analog converter (DAC) to subtract that voltage from the input, and then digitizes what remains of the input signal to get the lower half bi
Switching an on-going call to a different channel or cell in a wireless cellular network. Also known as "handoff."
The presence of frequencies in the output of a device that are not present in the input signal, and are multiples of components of the input signal. Clipping is a common cause but other nonlinearities can also introduce harmonics.
Highway Addressable Remote Transducer (HART) communication is a commonly used mode of transmission for digital signals that are superimposed on the analog signal of a 420mA current loop.
Highly accelerated stress test; highly accelerated steam and temperature.
High-Brightness LEDs are any of a new generation of LEDs bright enough for illumination applications such as automotive interior, exterior, and display; room and architectural illumination; task and general lighting; projection display; display backlights
Heterojunction bipolar transistor
Harmonic distortion
High Level Data Link Control: An ITU-TSS link layer protocol standard for point-to-point and multi-point communications.
High bit-rate Digital Subscriber Line: The oldest of the DSL technologies, it continues to be used by telephone companies deploying T1 lines at 1.5Mbps and requires two twisted pairs.
High-definition television: an all-digital system for transmitting a TV signal with far greater resolution than the analog standards (PAL, NTSC, and SECAM). A high-definition television set can display several resolutions, (up to two million pixels versus
Mechanical device that is thermally-connected to a heat-producing electronic component, designed to conduct heat away from the device. Most heat sinks are aluminum and employ fins to increase surface area and encourage the transfer of heat to the ambient
High-electron-mobility transistor
High frequency
High gain, low linearity
Hi-Z (or High-Z or high impedance) refers to an output signal state in which the signal is not being driven. The signal is left open, so that another output pin (e.g. elsewhere on a bus) can drive the signal or the signal level can be determined by a pass
Power electronics is the application of solid-state electronics to the control and conversion of electric power.
High voltage is defined by the DOE Electrical Safety Guidelines as over 600 volts. Generally considered to be a wire or cable with an operating voltageof over 600 volts.
An element connected between the supply and the load. High-side current sensing applications measure current by looking at the voltage drop across a resistor placed between the supply and the load.
Trademarked name for Home Radio Frequency, a networking technology which uses antennae and transmitters to provide wireless home networking via transmitted radio signals.
HomePlug (Powerline) is an industry-standard method for transmitting data via the power lines. It can transmit audio, video, control signals, etc. HomePlug is a trademark of the HomePlug Powerline Alliance; Powerline is the generic term for the method.
A power supply line controller which allows circuit boards or other devices to be removed and replaced while the system remains powered up. Hotswap devices typically protect against overvoltage, undervoltage, and inrush current that can cause faults, erro
High reliability
High-Speed Downlink Packet Access (HSDPA) is a 3G radio interface standard in the HSPA family for wireless and cellular handsets or datacards that increase the datarate and improve the traffic handling of existing UMTS standards.
High-Speed Packet Access (HSPA) is a collection of radio interface standards for wireless and cellular handsets or datacards that increase the datarate and improve the traffic handling of existing UMTS standards.
High-Speed Serial Interface: A short-distance communications standard for data rates from 2Mbps to 52Mbps.
High-Speed Uplink Packet Access (HSUPA) is a 3G radio interface standard in the HSPA family for wireless and cellular handsets or datacards that increase the datarate and improve the traffic handling of existing UMTS standards.
Hyper Text Markup Language: Coding language used to create web pages.
High-temperature semiconductor
Hyper Text Transport/transfer Protocol
An ESD test method where the ESD generator consists of a 100pF capacitor and a 1.5kohm series resistor.
Heating, Ventilation, and Air Conditioning: Industry term for the systems and technology responsible for the heating, ventilation, and air conditioning in buildings. HVAC systems regulate comfort (temperature and humidity), energy efficiency, and air qual
Hertz: A measure of frequency. An older term is cycles per second, or cps.
