Circuit Theory and Microelectronic Circuits Vocabulary Flashcards

Vocabulary flashcards covering key terms, abstractions, models, and circuit principles from the lecture notes.

Lumped Circuit Abstraction

An assembly formed by capping a set of lumped elements that obey the lumped matter discipline using ideal wires to perform a specific function.

Ideal Wire

A wire that acts as an ideal conductor and offers zero resistance.

Volt

The unit of measure for voltage, equal to one joule per coulomb ($1\,\text{J/C}$), representing the work done in moving a unit charge between two terminals against an electrical field.

Ampere

The unit of measure for current, equal to one coulomb per second ($1\,\text{C/s}$), defined as the rate of flow of charge from one terminal to another.

Node

Any point in a circuit where two or more element terminals are connected using wires.

Port

A pair of terminals that offer an alternative view of how electronic access is made to an element.

Ohm's Law

An abstraction for resistive material behavior stating that the terminal voltage is linearly proportional to the terminal current ($v = iR$).

Open Circuit

A circuit element through which no current flows regardless of its terminal voltage, behaving like a linear resistor in the limit $R \rightarrow \infty$.

Short Circuit

A circuit element across which no voltage can appear regardless of the current through it, behaving like a linear resistor in the limit $R \rightarrow 0$.

Associated Variables Convention

A circuit convention that defines current to flow into the device terminal assigned to be positive in voltage.

Conductance

The reciprocal of resistance, denoted by $G = \frac{1}{R}$, with units of Siemens ($\text{S}$).

Ideal Voltage Source

A device that maintains a constant voltage at its terminals regardless of the amount of current drawn from those terminals.

Independent Voltage Source

A voltage source that supplies a voltage independent of the rest of the circuit.

Dependent Voltage Source

A voltage source that supplies a voltage commanded by a signal from within the circuit of which it is a part.

Ideal Current Source

A source that maintains its output current at a constant value $I$ regardless of the voltage across its terminals.

RMS Value

The value of a DC signal that would produce the same average power dissipation as a periodic signal over one cycle.

Amplifier

A device that provides power gain, meaning the $V \times I$ product of the output exceeds that of the input.

Triode Region

The operating region of a MOSFET where $v_{GS} \ge V_T$ and $v_{DS} < v_{GS} - V_T$.

Saturation Region

The operating region of a MOSFET where $v_{GS} \ge V_T$ and $v_{DS} \ge v_{GS} - V_T$.

Switch (S) Model

The simplest model for a MOSFET that captures its ON-OFF switching behavior as either a short circuit or an open circuit.

Switch-Resistor (SR) Model

A MOSFET model that represents the ON state as a fixed internal resistance $R_{ON}$ between the drain and source.

Switch-Current Source (SCS) Model

A MOSFET model applicable in the saturation region that models the drain-to-source channel as a voltage-controlled current source.

Switch-Unified (SU) Model

A MOSFET model combining a continuous nonlinear resistor representation in the triode region with the SCS model in the saturation region.

Load Line

A line representing the affine relationship between output current and voltage forced by a load resistor in an amplifier circuit.

Static Discipline

A specification for digital devices requiring them to produce valid output voltages satisfying output thresholds ($V_{OL}$, $V_{OH}$) given valid input voltages satisfying input thresholds ($V_{IL}$, $V_{IH}$).

Noise Margin

The absolute value of the difference between the prescribed output voltage for a logical value and the corresponding forbidden region threshold for the receiver.

Kirchhoff's Current Law (KCL)

A circuit law derived from Maxwell's Equations stating that the algebraic sum of all branch currents flowing into any node must be zero ($\sum_{n=1}^N i_n = 0$).

Kirchhoff's Voltage Law (KVL)

A circuit law derived from Maxwell's Equations stating that the algebraic sum of all branch voltages around any closed path or loop must be zero ($\sum_{n=1}^N v_n = 0$).

Thévenin Equivalent Circuit

An abstracted model of a linear network at a pair of terminals consisting of an open-circuit voltage source $v_{TH}$ in series with an equivalent resistance $R_{TH}$.

Norton Equivalent Circuit

An abstracted model of a linear network at a pair of terminals consisting of a short-circuit current source $i_N$ in parallel with an equivalent resistance $R_N$.

Quality Factor ($Q$)

A gauge of resonance sharpness defined as $Q = \frac{\omega_o}{2\alpha}$, or the ratio of total stored energy to average energy dissipated per radian at resonance.

Transfer Function

The ratio of the complex amplitude of the network output signal to the complex amplitude of the network input signal as a function of frequency.

Zero-Input Response (ZIR)

The response of a circuit or system due entirely to initial stored energy, with all external drives set to zero.

Zero-State Response (ZSR)

The response of a circuit or system to an applied input drive signal, assuming zero initial stored energy.

Propagation Delay ($t_{pd}$)

The maximum time interval required for a signal transition at an input terminal to propagate and produce a valid voltage level at an output terminal.

Operational Amplifier (Op Amp)

A high-gain multistage two-input differential amplifier designed to approximate an ideal voltage-controlled voltage source.