Chapter 8 Digital Electronics

DIP

A very common IC package with two parallel rows of pins intended to be inserted into a socket or through holes drilled in a printed circuit board

Transmission gate (bilateral switch)

CMOS circuit that acts like a single pole, single throw switch controlled by an input logic level

Noise immunity

Circuit's ability to tolerate noise voltages on its inputs

Latch-up

Condition of dangerously high current in a CMOS IC caused by high-voltage spikes or ringing at device input and output pins.

Power-supply decoupling

Connection of a small RF capacitor between ground and Vcc near each TTL integrated circuit on a circuit board.

CMOS (Complementary Metal-Oxide-Semiconductor)

IC technology that uses MOSFETs as the principal circuit element. This logic family belongs to the category of unipolar digital ICs

N-MOS (N Channel Metal-Oxide-Semiconductor)

IC technology that uses N-channel MOSFETs as the principal circuit element

P-MOS (P Channel Metal-Oxide-Semiconductor)

IC technology that uses P Channel MOSFETS as the principal circuit element

Floating inputs

Input signal that is left disconnected in a logic circuit

Interfacing

Joining of dissimilar devices in such a way that they are able to function in a compatible and coordinated manner; connection of the output of a system to the input of a different system with different electrical characteristics.

Fan-out

Maximum number of standard logic inputs that the output of a digital circuit can reliably drive

MOSFETs

Metal-oxide-semiconductor field-effect transistor

Noise margin

Quantitative measure of noise immunity

Totem pole

Term used to describe the way in which two bipolar transistors are arranged at the output of most TTL circuits

Electrostatic discharge (ESD)

The often detrimental act of the transfer of static electricity (i.e., an electrostatic charge) from one surface to another. This impulse of current can destroy electronic devices.

Current sinking

The output of a logic circuit sinks current from the input of the logic circuit that is driving

Current sourcing

The output of a logic circuit sources, or supplies, current to the input of the logic circuit that is driving.

Surface-mount technology (SMT)

a method of manufacturing circuit boards whereby ICs are soldered to conductive pads on the surface of the boards

Bus contention

a situation in which the outputs of two or more active devices are placed on the same bus line every time

Low voltage differential signaling (LVDS)

a technology for driving high speed data lines in a low voltage systems that uses two conductors and reverses the polarity to distinguish between high and low

buffer/driver

circuit designed to have a greater output current and/or voltage capability than an ordinary logic circuit

analog voltage comparator

circuit that compares two analog input voltages and produces an output that indicates which input is greater

Voltage-level translator

circuit that takes one set of input voltage levels and translates it to a different set of output levels

TTL

integrated circuit technology that uses the bipolar transistor as the principal circuit element

Current-sinking transistor (pull-down transistor)

name given to the output transistor of a TTL circuit. This transistor is turned on when the output logic level is low

Wired-AND

term used to describe the logic function created when an open collector outputs are tied together

Logic pulser

testing tool that generates a short duration pulse when actuated manually

Lead pitch

the distance between the centers of adjacent pins on an IC

Open-collector output

type of output structure of some TTL circuits in which you only have one transistor with a floating collector is used

Tristate

type of output structure that allows three types of output states, HIGH and LOW, and high impedance