Electronic Engineering Glossary Terms

Flip Chip. A monolithic IC packaging technique that eliminates the need for bonding wires. A semiconductor chip that uses larger extended bonding pads. A semiconductor device which has all terminations on one side, in the form of bump contacts, has a passivated surface and has been flipped over and attached to a matching substrate.

Flip-Flop. A device having two stable states and two input terminals (or types of input signals), each of which corresponds with one of the two states. The circuit remains in either state until caused to change to the other state by application of a voltage pulse. A device that may assume either one of two reversible, stable states. A similar bistable device with an input that allows it to act as a single-stage binary counter. The four basic types of Flip Flops include a D Flip Flop, a T flip flop, an RS flip flop and a JK Flip Flop. Examples ICs include a 7474 [graphic to right] or a 74174 D Flip Flop. Also refer to Multivibrator.

Floating Gate. A gate electrode that is electrically floating, and has no direct electrical connection.

Floating Input. An input pin that is not tied to a supply rail and could float to an invalid logic level. An input pin that does not have an internal pull-up or pull-down and requires an external pull-up resistor which is not present. An input pin with no defined logic level and will float to any voltage, however most pins slowly drift high. An input that is not connected to a source.

Floppy. The Floppy disk drive stored data on a small, circular piece of metal-coated plastic. A Floppy disk drive could read and write data to/from the disk and it's controller. The transfer speed of a FDD is relatively slow, and the data storage capacity vary low. Data transfer speeds for Floppy Disk Drives [FDD] normally are 250KBps for the 720KB disk size and 500KBps for the 1.44MB disk size. Two common size devices are produced for the 3.5 inch floppy drive; the standard version 25.4 x 101.6 x 146mm [H x W x D], and a reduced size version 12.7 x 96 x 126mm [H x W x D]. FDD devices are obsolete and were replaced in 2005 by USB flash drives. [FDD Manufacturers]

Float Charge. Float charge is the voltage required to counteract the self-discharge of the battery at a certain temperature.

Flow-through. A pin configuration used with some ICs that align the I/O pins so the input functions flow-through to the output pins.

Fluorescent Lamp. A lamp that uses Fluorescence to generate light. Also see CCFL Lamp vendors.

Flutter. Rapid variation of signal parameters, such as amplitude, phase, and frequency [used with sound recording or reproduction]. Undesired changes in the frequency of signals during the reproduction of a magnetic tape produced by speed variations of the magnetic tape during recording or reproducing.

Flux. In electrical or electromagnetic devices, a general term used to designate collectively all the electric or magnetic lines of force in a region. The measure of the strength of a field of force in a specific area. A solution that removes surface oxides from metals being soldered.

Flux Density. The number of magnetic lines of force passing through a given area.

Fly-by-Optic. An avionics bus that uses fiber-optic interfaces and fiber cable to replace copper wire. See Fly-By-Wire.

Fly-by-Wire. A term used in the aerospace industry that denotes a control system that replaces traditional mechanical or hydraulic linkages with electronic connections between control units that drive electro-mechanical actuators. Also refer to; Avionic Bus Descriptions.

F-22 Flight Displays

Flywheel Effect. The ability of a resonant circuit to operate continuously because of stored energy or energy pulses.

FMAX. [Frequency Maximum] The highest frequency a component will operate to. The highest input clock frequency which causes a flip flop to cease to toggle.

FM Discriminator. A circuit that converts variations in frequency [FM] to variations in amplitude. A circuit that functions as a frequency to voltage converter.

FM Receiver. A receiver that decodes a Frequency Modulated signal to recover encoded information.

FM Receiver Block Diagram

Focusing Anode. An electrode of a CRT that is used to focus the electrons into a tight beam.

Folded Dipole. An ordinary half-wave antenna (dipole) that has one or more additional conductors connected across the ends parallel to each other. Antenna Dictionary

Footcandle. A unit of illuminance, light intensity, or brilliance.

Footprint. The amount of space taken up by a component on a surface, as in a printed wiring board.

Forbidden Band. The energy band in an atom lying between the conduction band and the valence band. Electrons are never found in the forbidden band but may travel back and forth through it. The forbidden band determines whether a solid material will act as a conductor, a semi-conductor, or an insulator.

Fork Contacts. A type of contact having two prongs in the shape of a fork, or tuning fork. The diagram to the right shows an example.

Form Factor. The size of a piece of gear in length, width and depth. The defined size of an equipment chassis, PC board or rack or any other component. For example a a mother board as a particular size or form factor. Read more on Board Form Factors.

Forward AGC. The type of AGC that causes an amplifier to be driven towards saturation. Also see the Radar section for AGC.

Forward Bias. An external voltage that is applied to a PN junction in the conducting direction so that the junction offers only minimum resistance to the flow of current. Conduction is accomplished by majority current carriers (holes in P-type material; electrons in N-type material). Refer to the graph to the right. The bias which tends to produce current flow in the forward direction

Forward Resistance. The smaller resistance value observed when you are checking the resistance of a semiconductor.

Forward Voltage Drop. The voltage drop across a semiconductor as current flows through a rectifier in the forward direction.

Foster-Seeley Discriminator. A circuit that uses a double-tuned RF transformer to convert frequency variations in the received FM signal to amplitude variations. Also known as a phase-shift discriminator. In the transistor circuit, capacitor C1 and inductor L1 form the collector tank circuit. While C2 and L2 form the secondary tank circuit. Both tank circuits are tuned to the center frequency of the incoming FM signal.

Foster-Seeley Discriminator

Fourier analysis. The definition of a periodic waveform of arbitrary shape as a summation of sine waves having specific amplitudes and phases, and having frequencies corresponding to the harmonics of the waveform being defined.

Four-Wire Circuit. A two wire circuit with two paths, one for each direction.