Glossary of Key Terms
Glossary of Key Terms
| Term | Definition |
| 555 Timer | An 8-pin IC named for the three 5KΩ resistors in its voltage divider network, useful for generating accurate time delays and non-sinusoidal oscillations like square, ramp, and pulse waves. |
| Active Filter | An electronic circuit consisting of an active element like an op-amp along with passive elements (resistors, capacitors) that allows certain frequency components and rejects others. |
| Adder (Summing Amplifier) | An op-amp based arithmetic circuit that produces an output equal to the sum of the input voltages applied at its inverting terminal. |
| Analog Integrated Circuits | Integrated circuits that operate over an entire range of continuous values of signal amplitude. |
| Analog Signal | A time-varying signal that has any number of values for a given time slot. |
| Analog to Digital Converter (ADC) | An electronic circuit that converts an analog signal into a digital signal represented by a binary code. |
| Anti-Logarithmic Amplifier | An electronic circuit that produces an output proportional to the anti-logarithm (exponential) of the applied input. |
| Arithmetic Circuits | Electronic circuits that perform arithmetic operations such as addition and subtraction. |
| Barkhausen Criteria | The two conditions required for a sinusoidal oscillator to produce sustained oscillations: the loop gain must be ≥ 1, and the total phase shift around the loop must be 0° or 360°. |
| Clamper | A wave shaping circuit that produces an output similar to the input but with a shift in the DC level, without changing the peak-to-peak amplitude. |
| Clipper | A wave shaping circuit that produces an output by removing a part of the input above or below a reference value. |
| Common Mode Rejection Ratio (CMRR) | The ratio of the closed-loop differential gain to the common-mode gain of an op-amp. |
| Comparator | An electronic circuit that compares two inputs and produces an output indicating which input is greater or lesser, typically at saturation voltages (+V_{sat} or -V_{sat}). |
| Conversion Time | The amount of time required for a data converter to convert data from one form (e.g., analog) to another (e.g., digital). |
| Current to Voltage Converter | An electronic circuit that takes current as the input and produces a proportional voltage as the output. |
| Differentiator | An electronic circuit that produces an output equal to the first derivative of its input. |
| Digital Integrated Circuits | Integrated circuits that operate only at a few pre-defined levels instead of a continuous range of values. |
| Digital Signal | A signal that varies suddenly from one level to another and has a finite number of values for a given time slot. |
| Digital to Analog Converter (DAC) | An electronic circuit that converts a digital input signal (binary code) into an analog output signal. |
| Direct Type ADC | An ADC that performs conversion by directly utilizing an internally generated equivalent digital code for comparison with the analog input. Examples include flash, counter, and successive approximation ADCs. |
| Electronic Circuit | A group of electronic components connected for a specific purpose. |
| Filter | An electronic circuit that allows certain frequency components and/or rejects others. |
| Fixed Voltage Regulator | A voltage regulator that produces a fixed DC output voltage, which can be either positive (e.g., 78xx series) or negative (e.g., 79xx series). |
| Flash Type ADC | The fastest type of ADC, which uses a parallel bank of comparators to produce an equivalent digital output for an analog input in a very short time. |
| Full Wave Rectifier | A circuit that produces positive half cycles at the output for both the positive and negative half cycles of the input AC signal. |
| Half Wave Rectifier | A circuit that produces an output for one half cycle of the input and zero output for the other half cycle. |
| Ideal Op-Amp | A theoretical operational amplifier with infinite open-loop voltage gain, infinite input impedance, zero output impedance, infinite bandwidth, infinite CMRR, and infinite slew rate. |
| Indirect Type ADC | An ADC that performs conversion by first converting the analog input into a linear function of time or frequency, and then producing the digital output. An example is the Dual Slope ADC. |
| Integrated Circuit (IC) | A single chip of semiconductor material on which multiple electronic components (both active and passive) are interconnected. |
| Integrator | An electronic circuit that produces an output that is the integration of the applied input. |
| Inverting Amplifier | An op-amp circuit that takes input through its inverting terminal and produces an amplified, inverted (180° phase-shifted) output. |
| Inverting Comparator | An op-amp based comparator where the input voltage is applied to the inverting terminal and a reference voltage is applied to the non-inverting terminal. |
| Linear Integrated Circuits | An analog IC where a linear relation exists between its voltage and current. IC 741 is an example. |
| Logarithmic Amplifier | An electronic circuit that produces an output proportional to the logarithm of the applied input. |
| Non-Inverting Amplifier | An op-amp circuit that takes input through its non-inverting terminal and produces an amplified output with no phase shift. |
| Non-Inverting Comparator | An op-amp based comparator where the input voltage is applied to the non-inverting terminal and a reference voltage is applied to the inverting terminal. |
| Open Loop Voltage Gain | The differential gain of an op-amp without any feedback path. |
| Operational Amplifier (Op-Amp) | A direct-coupled high-gain amplifier integrated circuit that can be used to perform various linear, non-linear, and mathematical operations. |
| Oscillator | An electronic circuit that produces a periodic signal by converting input energy from a DC source into an AC output energy. |
| Output Offset Voltage | The voltage present at the output of an op-amp when its differential input voltage is zero. |
| Phase Locked Loop (PLL) | An electronic system consisting of a phase detector, active low-pass filter, and a voltage-controlled oscillator, used in communication systems to lock onto and track the frequency of an input signal. |
| Practical Op-Amp | A real-world operational amplifier with characteristics that deviate from the ideal, such as very high (but not infinite) input impedance and low (but not zero) output impedance. |
| R-2R Ladder DAC | A type of DAC that uses a repeating ladder network of resistors with only two values (R and 2R), making it easier to fabricate accurately compared to weighted resistor DACs. |
| RC Phase Shift Oscillator | An oscillator that uses an inverting amplifier and a feedback network of three cascaded RC sections to produce a total phase shift of 360° for sinusoidal oscillation. |
| Rectifier | An electronic circuit that produces either a DC signal or a pulsated DC signal when an AC signal is applied to it. |
| Resolution | The minimum amount of change in an analog input voltage required to produce a change in the digital output, determined by the number of bits in the converter. |
| Sinusoidal Oscillator | An oscillator that produces sinusoidal oscillations. |
| Slew Rate | The maximum rate of change of an op-amp’s output voltage due to a step input voltage, typically measured in V/μSec. |
| Square Wave Generator | An electronic circuit that generates a square wave, often using an op-amp with both positive and negative feedback. |
| Subtractor (Difference Amplifier) | An op-amp based arithmetic circuit that produces an output equal to the difference of the input voltages applied at its inverting and non-inverting terminals. |
| Successive Approximation ADC | A type of direct ADC that generates a digital output by successively comparing the analog input with internally generated values, converging on the final digital code. |
| Transconductance | The gain of a Voltage to Current Converter, defined as the ratio of the output current to the input voltage. |
| Transresistance | The gain of a Current to Voltage Converter, defined as the ratio of the output voltage to the input current. |
| Triangular Wave Generator | An electronic circuit that generates a triangular wave, typically by cascading a square wave generator with an integrator. |
| Virtual Short | A concept in op-amp analysis where the voltage at the inverting input terminal is considered equal to the voltage at the non-inverting terminal due to the high open-loop gain. |
| Voltage Follower | A special case of a non-inverting amplifier with a gain of one, where the output voltage is equal to and follows the input voltage. |
| Voltage Regulator | An electronic circuit or IC that maintains a constant DC voltage at the output irrespective of fluctuations in the input voltage or variations in the load current. |
| Voltage to Current Converter | An electronic circuit that takes voltage as the input and produces a proportional current as the output. |
| Waveform Generator | An electronic circuit that generates a standard waveform, such as a square or triangular wave. |
| Wave Shaping Circuits | Electronic circuits, such as clippers and clampers, that produce a desired shape at the output from an applied input waveform. |
| Weighted Resistor DAC | A type of DAC that uses a set of binary weighted resistors in an inverting adder circuit to convert a digital input to an analog output. |
| Wien Bridge Oscillator | An oscillator that uses a non-inverting amplifier and a lead-lag feedback network (Wien bridge) to produce sinusoidal oscillations with a total phase shift of 0°. |