Glossary Terms and Definitions Beginning with the Letter B

B 1. Bel: Measurement of a signal's power compared to a reference; also, measurement of sound pressure. See the more commonly used term, "decibel," or, "dB."

2. Symbol for magnetic flux density or magnetic field, as in "B-field."

B-Field See B
Backup Step-Up Step-up, switching-regulator power supply with a backup battery switchover.
Balanced See Differential Signaling
band See Bandwidth
Bandwidth 1. Bandwidth (BW) is a range of frequencies, or information, that a circuit can handle or the range of frequencies that a signal contains or occupies.

Example: An AM broadcast radio channel in the US has a bandwidth of 10kHz, meaning that it occupies a 10kHz-wide band, such as the frequencies from 760kHz to 770kHz.

2. The amount of data a digital channel or line can handle, expressed in bits per second (bps), kilobits per second (kbps), baud, or a similar measure.

Base Station A base station (or basestation) is a wireless transceiver at a fixed location (e.g. atop a telephone pole) which is part of a wireless communications network, e.g. the cell phone network. Typically, the base station connects to any cell phones in its area and relays the calls to the wired network.

A femto base station is a smaller, personal base station which might cover a home or building and connect via a DSL Internet connection.

Base Transceiver Station See BTS
Baseband See UWB
Baseline The electrical signal from a sensor when no measured variable is present. Often referred to the output at no-load condition.
Basestation See BTS
Basic Spacing between Centers See BSC
Bass Boost Circuitry that boosts the bass response of the amplifier, improving audio reproduction, especially when using inexpensive headphones.
Battery Backed See Battery Backup
Battery Backup A feature of microprocessor supervisory circuits and some power supplies to switch between a main power source and a battery.
Battery Bridge See Bridge Battery
Battery Freshness Cap See Battery Freshness Seal
Battery Freshness Seal A feature in microprocessor supervisory circuits which disconnects a backup battery from any down-stream circuitry until VCC is applied the first time. This keeps a backup battery from discharging until the first time a board is plugged in and used, and thus preserves the battery life.
Battery Fuel Gauge A feature or device that measures the accumulated energy added to and removed from a battery, allowing accurate estimates of battery charge level.
Battery Monitor A feature that monitors the voltage on a battery and indicates when the battery is low. It is usually implemented using a comparator to compare the battery voltage to a specified level. May also include functions such as charging, remaining capacity estimation, safety monitoring, unique ID, temperature measurement, and nonvolatile (NV) parametric storage.
Battery Switchover A circuit that switches between the higher of a main supply and a backup battery.
BBM See Break-Before-Make
BCD Binary-coded decimal: Representation of a number in which each decimal digit (0-9) is encoded in binary, with four bits per decimal digit.
Bel See B
BER Bit Error Rate: A measure of the number of erroneous bits which can be expected in a specified number of bits in a serial stream.
BERT Bit Error Rate (BER) Tester: A piece of test equipment which determines the bit error rate for a device under test (DUT).
Beyond-the-Rails™ Maxim's name for a feature of an IC that can process inputs and provide output voltages that exceed the supply rails. The feature is achieved through on-chip integration of necessary supply rails.
BGA Ball grid array: A packaging technology.
bi-phase modulation See BPSK
Bidirectional The device accommodates signals traveling either direction though a single channel.
Binary phase-shift keying See BPSK
Bipolar Inputs An input which accommodates signals both above and below ground.
Bipolar Junction Transistor A Bipolar Junction Transistor, or BJT, is a solid-state device in which the current flow between two terminals (the collector and the emitter) is controlled by the amount of current that flows through a third terminal (the base).

Contrast to the other main transistor type, the FET, in which the ouput current is controlled by input voltage (rather than by input current).

BIST Built-in self-test.
Bit Banging A technique which uses the general-purpose ports of a microcontroller to emulate a serial interface standard (I2C, SPI, etc).
Bit Error Rate See BER
Bit Error Rate (BER) Tester See BERT
Bit Error Ratio The number of erroneous bits divided by the total number of bits transmitted, received, or processed over some stipulated period.
BJT See Bipolar Junction Transistor
Blade Server A blade server is a computer system on a motherboard, which includes processor(s), memory, a network connection, and sometimes storage. The blade idea is intended to address the needs of large-scale computing centers to reduce space requirements for application servers and lower costs.
Blink Control Controls the display segment blink rate.
BLM Ball limiting metal
Bluetooth A technology that allows voice and data connections between a wide range of mobile and stationary devices through short-range digital two-way radio. For instance, it specifies how mobile phones, Wireless Information Devices (WIDs), computers and PDAs interconnect with each other, with computers, and with office or home phones.
BLVDS Bus low-voltage differential signal
BOC Bit-oriented code
Boost See Step-Up DC-DC
Boost Controller See DC-DC Controller
Boost Converter A power supply that steps an input voltage up (boosts it) to a higher, regulated voltage.
Boost DC-DC See Step-Up DC-DC
Boost DC/DC See Step-Up DC-DC
Booster See Step-Up DC-DC
Bootstrap Often refers to using the output of a step-up converter to drive the main power FET switch, providing more gate drive than the input can supply alone. Also refers to using a switched capacitor to boost the voltage of a node.
Bounded Jitter See Deterministic Jitter
BPON Broadband passive optical network
bps See Bandwidth
BPSK Binary phase-shift keying
BR See Lithium batteries
BRD Band-rate divisor
Break-Before-Make Break-Before-Make: A switch that is configured to break (open) the first set of contacts before engaging (closing) the new contacts. This prevents the momentary connection of the old and new signal paths.

Applies to mechanical systems (e.g. that use relays or manual switches) and to solid-state analog multiplexers and switches.

BRI Bit-rate interface
Bridge Battery A battery intended to provide power to system memory while the main battery is replaced.
Bridge Tied Load See Bridge-Tied Load
Bridge-Battery See Bridge Battery
Bridge-Tied Load Used in audio applications, the load (a speaker in this case) is connected between two audio amplifier outputs (it "bridges" the two output terminals).

This can double the voltage swing at the speaker, compared to a speaker that is connected to ground. The ground-tied speaker can have a swing from zero to the amplifier's supply voltage. A BTL-driven speaker can see twice this swing because the amplifier can drive either the + terminal of the speaker or the — terminal, effectively doubling the voltage swing.

Since twice the voltage means four times the power, this is a major improvement, especially in applications where battery size dictates a lower supply voltage — e.g. automotive or handheld applications.

Bridged Battery See Bridge Battery
Bridged Tied Load See Bridge-Tied Load
Brightness Although the terms "brightness" and "luminance" are often used interchangeably, they are different. Luminance is the light intensity; brightness is how it is perceived by the human eye.
Broadband A transmission medium with enough bandwidth to carry multiple voice, video, or data channels simultaneously.

This technique is used, for example, to provide fifty CATV channels on one coaxial cable; or to provide Internet access over cable TV; or to add DSL to a voice-grade telephone line.

A common technique is frequency-division. Each channel is modulated to a different frequency band and combined in the transmission medium. It is demodulated to its original frequency at the receiving end. Channels are separated by guardbands (empty spaces) to ensure that each channel will not interfere with its neighboring channels.

Brown and Sharpe wire gauge See AWG
Brownout A condition where the voltage supplied to the system falls below the specified operating range, but above 0V.
BSC BSC (Basic Spacing between Centers) is a term that appears on IC package drawings in reference to dimensions between pins.

"Basic" spacing is nominal and can change with conditions. For example, the distance between the rows of pins on a DIP (dual inline package) is BSC because it changes when the auto insertion machine grabs the part, and again when the part is inserted. The BSC dimension, in this case, is the dimension of the hole spacing that the part will fit into, rather than the dimensions of the part itself.

BSLF Best-straight-line fit
BT Butterworth (filter)
BTL See Bridge-Tied Load
BTS Base Transceiver Station: The stationary component of a cellphone system includes transmit-receive units and one or more antennae. The combined systems (often including multiple co-located systems and ganged directional antennae) is called a cell-site, a base station, or a base transceiver station (BTS).
Buck A "buck" or "step-down" switch-mode voltage regulator is one in which the output voltage is lower than its input voltage.

Note: A customer asked the origin of the term and no one seems to know! A buck regulator is a step-down regulator, as opposed to boost. We think it's an American term — in England it was always "step-down."

Buck means to resist or reduce (as in "buck the trend"), and hence was used to denote a step-down. Conveniently, it alliterates with the opposite, a boost regulator.

See application note 660, "Regulator topologies for battery-powered systems."
Buck Controller See DC-DC Controller
Buck DC-DC See Buck
Buck Regulator See Buck
Buck Switcher See Buck
Buck-Boost A switch-mode voltage regulator in which output voltage can be above or below the input voltage.

See application note 660, "Regulator topologies for battery-powered systems."
Buck-Boost Converter See Buck-Boost
Buck-Boost Regulator See Buck-Boost
Buck/Boost See Buck-Boost
Buck/Boost Converter See Buck-Boost
Buck/Boost Regulator See Buck-Boost
Burst Dimming Burst Dimming is a method of controlling the brightness of cold cathode fluorescent lamps (CCFL) by turning the lamps on and off at a rate faster than the human eye can detect. The on/off rate is nominally 100Hz to 300Hz. The higher the ratio of on-time to off-time, the brighter the lamps will be. Because of CCFL response times, on-time to off-time ratios of less than 1% are not practical.
Burst Mode 1) A temporary high-speed data-transfer mode that can transfer data at significantly higher rates than would normally be achieved with nonburst technology.

2) The maximum short-term throughput which a device is capable of transferring data.

Burst Mode Applications See Burst Mode
Bus Data path that connects to a number of devices. A typical example is the bus a computer's circuit board or backplane. Memory, processor, and I/O devices may all share the bus to send data from one to another. A bus acts as a shared highway and is in lieu of the many devoted connections it would take to hook every device to every other device.

Often misspelled "buss."

BW See Bandwidth
BWLS Bandwidth, Large Signal
BWSS Bandwidth, Small Signal