Electronic Engineering Glossary
Ampere. The SI unit for electric current.
An interface with three signal outputs for a rotary or linear incremental encoder. While rotating in one direction, the the A and B channels deliver equal-length pulses, shifted by 90 degrees (in quadrature) so that the A channel pulse rises halfway between two successive B pulse transitions. The phase-shift sequence of the A and B edges indicates the motion direction. One time per revolution or per linear traverse, an index pulse occurs on the Z channel, indicating the zero position (assuming only two magnetic poles per rotation/traverse).
Alternating current input. This type of electrical current flows back and forth at regular time intervals. The two standard currents are 60 cycles per second (frequency of 60Hz) and 50 cycles per sencond (frequency of 50Hz).
An electrical circuit that transforms an alternating current (AC) input into a direct current (DC) output.
Value that represents how close the average measurement gets to the real value of a measured quantity.
Analog-to-digital converter. A circuit that converts analog signals to a number expressed as a group of bits.
Advanced asynchronous modulation (AAM) mode, or light-load AAM mode. A control technique employed to optimize efficiency during light-load or no-load conditions. This control scheme helps achieve high efficiency by scaling down the frequency to reduce switching and gate driver losses.
filter that uses the sensor ouptut (the first state, e.g. the position) and it's derivative over time (the second state, e.g. the speed) to predict the accurate first state (filter output, the precise position).
A switching power converter that uses a power diode in the low-side switch. The inductor current flows only in one direction in these converters, and never goes negative.
Advanced technology extended. This is the standard power supply format for modern motherboards.
Bias current trimming. A technique to linearize the output of an MPS magnetic rotary angle sensor by adjusting the gain of the Hall array in either the X or Y axis.
Brushless direct current motor. Characterized by having a permanent magnet on the rotor, and a stator winding that generates a rotating magnetic field by means of electronic commutation. BLDC motors have high efficiency and power density.
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Circuit used to drive the high-side MOSFET in a switching circuit. The circuit is used to boost the gate voltage over the drain voltage of the MOSFET.
Motor type characterized by having a stator generating a static magnetic field and a rotor generating a magnetic field that is always perpendicular to the stator one. This is achieved by installing different windings on the rotor and supplying them alternately while the rotor is rotating using a commutator connected to the power supply through brushes.
A switching power supply capable of producing a DC output voltage either greater than or less than the DC input voltage.
Controller area network. Multicast-based communications protocol first used in automotive applications.
Industrial communications protocol based on the Controller Area Network (CAN).
Continuous conduction mode. This is a constant frequency operation method in which the inductor current does not reach zero. Used in medium-high power.
A control technique that ensures low input current harmonics in both CCM and DCM mode. This achieves a high PF and increases efficiency.
DC/DC converter which uses switching capacitors to achieve a higher or lower output voltage. It does not have an inductor.
Protection circuit, which is tripped when high current flows through it. It opens the circuit.
Mathematical transformation used in three-phase systems that allows converting the coordinates of three-phase variables from being expressed in the abc reference frame, to an αβγ frame where the axes are mutually orthogonal.
The shortest path through air between two conductive parts.
A system control architecture where the system output is measured and fed back to the system to control the behavior of that output.
A single integrated circuit that controls both PFC and LLC topologies at the same time, and integrates the drivers and the bootstrap. This is a very low-cost, compact solution.
The switching frequency value of the power converter is contant.
Electronic circuit that controls the switching devices of a power converter.
Adaptive constant-on-time (COT) control. A variable switching frequency control based on pulse-frequency modulation (PFM). This control provides a fixed-length pulse during the time in which the switch is on, while there is a variable length pulse during the time in which the switch is off.
Two inductors or coils that affect their own electrical behaviors. The current that flows across one wire or coil induces a voltages across the other coil this is due to Faraday's law of induction. The amount of inductive coupling between two coils is measured by their mutual inductance, represented by the symbol M and in units of Henrys (H). This inductance depends on the geometrical properties of the coils, such as the number of turns, and the radius of the turns of each coil.
Critical conduction mode. This is a non-constant frequency operation method in which the inductor current reaches zero and suddenly starts increasing again. Used in low-medium power.
The shortest path across the surface of a material between two conductive parts.
Comparative tracking index. A measure of the electrical breakdown properties of an insulating material. A higher CTI index indicates that a lower minimum creepage distance is required.
The maximum and minimum current imposed to prevent damage on the converter.
A fixed switching frequency control based on pulse-width modulation (PWM). This control technique depends on the inductor current. The switch turns off when a certain peak current is reached, and turns on with the clock signal. The major avantage of this control technique is the fast transient response to output current changes. Its disavantage is its noise sensitivity at low duty cycles.
Digital-to-analog converter. A circuit that is able to convert a quantity expressed as a number to an analog voltage level.
The device implements the control of a switching power converter.
The device implements control and integrates active element such as MOSFETs or drivers to implement a complete DC/DC conversion. In a DC DC converter, the DC input is transformed into a DC output voltage that could be greater or smaller in magnitude than the DC input voltage.
The device implements control and integrates passive and active elements for the entire DC DC conversion.
Discontinuous conduction mode. This is a constant frequency operation method in which the inductor current reaches zero and remains there until the next switchig cycle. Used in low-medium power.
When constant-on-time (COT) control is implemented around a microcontroller.
Controls the PFC converter with an MCU. This increases the control performance in situations such as valley detection.
When pulse-frequency modulator (PFM) control is implemented around a microcontroller.
An electrical device composed of a passive switch that does not have a control terminal. This element allows the current to flow only in one direction (known as the forward direction), while blocking it in the opposite (reverse) direction. It is represented by the symbol D. The most common type of diode uses a p-n junction.
When pulse-width modulation (PWM) control is implemented around a microcontroller.
The change in a sensor's output when its operating conditions change (other than the parameter being measured), e.g. temperature drift, lifetime drift.
A circuit or component whose purpose is to control the voltage level of another component.
A switching converter that implements more than one single-phase controller. Interweaving phase controllers helps reduce ripple currents at the input and output.
An electromechanical device that transforms electrical energy to mechanical energy through the interaction of electromagnetic fields. Composed of a stator and a rotor. A magnetic field develops on each part, and their interaction generates torque which causes the rotor to spin.
There is not a direct current (DC) path for current flows or undesirable alternating current (AC) through a power converter. The isolation can be achieved by means of either transformer or coupled inductor. Some applications need to be isolated for safety reasons (e.g. protecting operators from high voltage at the workplace).
A device that generates the proper voltage level to power electroluminescent lights, usually consisting of a voltage booster.
In magnetic angle sensing applications, refers to the location of the sensor being positioned at the end of a rotating shaft relative to a magnet mounted on the end of the same shaft.
The systematic difference between the sensor output and the real quantity to be measured (e.g. the error), as a function of the quantity to be measured. The maximum deviation from zero of the error curve is the accuracy.
Energy-using product / energy-related product code of conductance. Defined as standby European regulations to mains connected devices since 2013. Fixed to <0.5W.
European Telecommunications Satellite Organization.
The changes that appear on the output voltage in front of any perturbation (load, input voltage changes, etc.) are almost negligible. Peak current mode is the most convenient control technique to achieve a fast transient response.
Period of time in which a fault is ignored to avoid falsely leading edges.
The output voltage or current is routed back to the converter to close the loop and be compared with the reference voltage.
Relative amplitude change of the output signal from a filter, as a function of the input frequency.
The simplest isolated power converter. Configured only with a coupled inductor, a MOSFET, and a diode. Typically used for >100W solutions.
Field-oriented control. A control algorithm used in motion control that consists of controlling the current flowing in the m.otor windings in order to create the maximum torque in the rotor, i.e. to create a flux in the stator perpendiculat to the rotor magnetic field.
A circuit employed to decrease the current limit under overload conditions.
A switching power supply capable of producing a DC output voltage that is either greater than or less than the DC input voltage, and providing electrical isolation via a transformer.
Adjustable frequency range.
An isolation method used in electrical systems to generate different voltage levels.
Gallium nitride. Wide bandgap material used in power semiconductors. It withstands higher voltage than silicone, and is faster.
Refers to the frequency degradation of a signal with respect to its main signal. Harmonic frequencies of a period signal (current or voltage) are integer multiples of the frequency of the main signal. As harmonic distortion of a signal increases, the periodic signal looks less like a sine wave. Therefore, a purely sinusoidal signal has no distortion.
If a fault condition on the power converter is detected, the output voltage will reduce to zero during a short period of time, then restart to try achieving normal operation. The on/off attempts of the power converter will occur until the fault condition disappears, which is why this behavior is called hiccup mode.
When a power converter handles large amounts of energy in a reduced volume.
DC/DC converter that can be supplied by a high volatge. Usually above 400V DC (from rectified AC input).
Inter-integrated circuit. A two-wire, synchronous, half-duplex, multi-master/multi-slave serial communication protocol. The two lines used are the SCL (serial clock), through which the maseter sets the communication frequency, and the SDA (serial data), where the data between masters and slaves is exchanged.
A two-wire, serial, half-duplex protocol used to configurate some controllers.
An electrical device (passive component) that stores electrical energy in the magnetic field when an electric current passes across it. Usually an inductor is made of wire wrapped around a magnetic core. It is represented by the symbol L, and measured in Henry (H) in SI units.
Device that converts voltage from DC to DC without using an inductor.
Integral nonlinearity. In measurements, this parameter specifies the maximum deviation between the device output and a linear fit of the output.
A circuit used to get an AC voltage output with variable frequency and/or amplitude out of a DC voltage supply.
The voltage that can be withstood between isolated primary and secondary circuits for a short period of time without damage. Usually caused by unintentional disturbance on the line due to a load change or fault condition. For UL/IEC 60950-1, it is defined as the rms value of the sinusoidal voltage that a device can sustain for 60 seconds without damage.
Semiconductor standards. These describe tests that have to be carried out for product verification, such as temperature cycling, etc.
Related material:
Japan Electronics and Information Technology Industries Association standards.
Loss of synchronization of a periodic signal, often with respect to a reference clock signal.
In a rotary magnetic angle sensor, refers to ratio of the radial magnetic field tangential magnetic field. k = Br / Bt
For rotary angle sensors, the time delay between the instant when a certain position is reached and the instant when this postion is reported at the sensor output.
Further reading:
A circuit that provides the necessary power for an LED or array of LEDs in order to guarantee that they operate in safely and with consistent brightness. There are two different types of LED Drivers: constant current source and constant voltage source.
A power converter operating at a small load current.
A voltage regulator that provides constant output voltage through a MOSFET that works in the linear region.
A type of resonant converter in which an inductor and a capacitor series are connected. It is excited with a frequency close to its resonance to achieve a ZVS condition.
A circuit capable of keeping a stable output voltage or current affected by any change in load.
Low dropout. LDO is a DC linear output voltage controller that requires a voltage drop between the input and the output voltage.
Low noise block. An LNB is a device used for satellite comunication systems.
Devices with an especially low height.
Refers to the low-side gate driver, where the source terminal is connected to ground.
In angle sensing, the angle of the magnetic vector in degrees.
Device that detects the linear or rotary position of a permanent magnet with magnetic sensors (usually Hall-effect or magneto-resistive elements), and reports this position in an incremental or absolute format.
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An invisible field of force produced on materials that are sensitive to magnetism, or due to the movement of electric charges (flow of electricity).
A sensor that is able to detect the intensity and direction of a magnetic field.
The magnetization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material, conventionaly represented by the letter M. M is zero outside of the magnetic material.
In angle sensing, the angle of the rotating shaft in degrees.
Microcontroller unit. In power electronics, this is widely used as a digital controller.
United States military standard. It describes the tests that have to be carried out for product verification depending on the consumer, such as EMC emissions, etc.
Metal-oxide-semiconductor field-effect transistor.
A circuit designed to drive the gate of power MOSFETs. The main purpose is maximizing the switching speed of the MOSFET.
A motor driver translates small power signals, generated by an MCU in order to obtain a desired behavior of the motor, into higher-power signals. The driver output can be directly fed to the motor if it has an integrated MOSFET power stage. Otherwise, the driver output is used to control the switching of external MOSFETs.
Web-based tool to calculate the main converter parameters.
Special protection features like overcurrent (OC), over-voltage (OV), over-temperature (OT) protection.
Newton meter. The SI unit for torque.
Amplitude of the noise, as a function of the frequency.
Non-volatile memory. Memory type that is able to keep data saved in it, even when its power supply is shut down.
Over-current protection. Protection that triggers when the current flowing in a component is higher than a threshold set for safety reasons. It avoids the damaging of components during overheating.
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Over-current protection with hiccup mode.
Any type of converter without a case.
Device that detects the position of a code wheel with optical sensors (usually LED and photodiodes), and reports this position in an incremental or absolute format.
Over-temperature protection. Protection that triggers when the temperature of a component rises above a certain threshold, since high temperatures can lead to permanent damage of the components.
Output voltage can be configurable through the I²C by the one-time programmable function, or by using a resistive voltage divider.
Over-voltage protection. Protection that triggers when the voltage across a component is higher than a threshold set for safety reasons. It avoids the damaging of components, such as the isolating materials being broken.
For motors, overload is a functioning condition that happens when the resistant torque applied to the motor is too high. The motor draws a current higher than the rated current and starts to heat. Overload can be sustained for a short time; but if it lasts too long, it can lead to damage or failure of components.
Mathematical transformation used to convert the coordinates of a variable from being expressed in a stationary xyz reference frame to a dq0 frame rotating around the z axis.
An object that, due to its physical characteristics, is able to generate its own magnetic field.
Power factor
Power factor correction. This is a circuit used to acheive better harmonic distorsion on an AC input.
Shifting one driving signal from the other. Used in full-bridge converters to achieve soft-switching.
Power management integrated circuit. A PMIC can carry multiple functions of power management. Most PMICs include diverse DC/DC converters or control circuit in a single chip, reducing the demands on space and system power.
Permanent magnet synchronous motor. This motor has a permanent magnet on the rotor, while on the stator a 3-phase distributed winding generates a rotating magnetic field. It shares some features with the BLDC motor, but has a better overall performance and higher cost.
Point of load. Converters that are close to the load to deliver high current.
A pair of north-south magnetic poles.
This pin is an open-drain power, which goes up after VFB reaches 90% x REF.
Semiconductor block or group of semiconductors which are assembled as a bigger package. Usually to be attached to a heatsink with screws. The key criteria for selecting a power solution is often size, efficiency, and cost. Power modules can offer small soluction size, provide an easy layout, reduce radiated emissions (EMI), increase power conversion efficiency, and improve reliability due to fewer external components being needed. This speeds up the power design cycle, reducing PCB complexity.
Value representing the repeatability of a measurement in a measurement system. A system is precise when a set of measurements performed in the same conditions returns measurements that are very close in value.
A DC/DC converter that offers the ability to adjust some parameters (e.g. output voltage, frequency, protection limits, control parameters, etc.).
Further Reading:
Selectable parameters of the DC/DC converter (e.g. output voltage, frequency, protection limits, control parameters, etc.).
Selectable soft-start time.
Adjustable switching frequency value through a resistor or I²C.
Power supply unit
There are two types of PFM: fixed on-time and fixed off-time. In fixed on-time mode, the fraction of time in which the switch signal is on is constant, while the fraction of time in which the modulated signal is off is variable. In fixed off-time mode, the fraction of time in which the switch signal is off is constant, while the fraction of time in which the modulated signal is on is variable.
The number of pulses per turn for each channel of an incremental ABZ encoder interface.
Pulse-width modulation. A technique used to achieve a desired average voltage value through very fast switching between two different voltage levels. The value to be transmitted is proportional to the duty cycle.
Refers to AAM mode.
A type of incremental encoder interface producing two phase-shifted waveforms (A and B), whose relative phase indicates the direction of rotation. The number of pulses on A and B varies with the programmed resolution. An optional index pulse Z (or I) indicates one complete magnetic rotation.
Radians per second. The SI unit for rotational speed.
A braking technique that allows energy recovery by making a current flow back to the power source when an electric motor decreases its speed.
Residual magnetic field (or magnetization) left in a magnetic material when the external magnetizing field is removed.
A measure of how close the sensor output value is to the previous reading when a measurment is repeated under the same conditions. Equivalent to precision. It is limited by the sensor noise (random variations) and aging (long-term drift). Refer to resolution.
In measuring systems, the smallest change of the measured quantity that can be detected by the measuring system. In practice, for digital sensors it is the least significant bit (LSB). If the noise of the sensor is greater than the LSB, it is defined as 3 times the rms noise, represented by σ (sigma). This quantity is often expressed in bits. For MPS MagAlpha angle sensors, one LSB represents an interval of 6 σ (±3 σ).
A type of converter that uses self-resonance to reduce switching losses.
The rotating part of an electrical motor.
Rotations per minute. A unit for rotational speed. 1rpm = 60/2π rad/s = 1/6 deg/s.
Serial communications standard. It is one of the first and is widely used.
A two-wire serial, asynchronous, half-duplex communication protocol. The two wires, A and B, are driven by the communicating devices to set the differential voltage on the line. This protocol allows devices to connect over long distances (up to 1200m) and has good noise rejection.
In electronics, this is usually related to the standard which must be met, such as IEC 60950.
The power converter can operate either CCM or AAM mode.
Variation rate when one parameter, different from the one to be measured, is changed (e.g. the temperature) but all the others remain constant.
Part of the sensor where the physical quantity is detected and amplified, before further signal processing ("back-end" processing).
Single-ended primary-inductor converter. A topology of DC/DC power converters. The DC output voltage can be either greater than or less than, but which has the same polarity as, the DC input voltage.
Silicon carbide. Wide bandgap material used in power semiconductors. It withstands a higher voltage than silicone, and is faster.
In magnetic angle sensing applications, refers to the location the sensor being positioned to the side of a magnet mounted on the rotating shaft.
Technology aimed at increasing the energy efficiency in lighting applications. Sensors and controllers are used to turn on and off the lights, or to adjust the brightness level based on external conditions (e.g. the availability of natural daylight).
System management bus. Based on I2C and used to communicate with power supplies (monitorizing voltages, temperatures, etc.)
A circuit capable of changing undesirable voltage transients.
System on chip. A chip where different type of modules are integrated (analog and/or digital). Its goal is to have a complete system in a chip (memory, Wi-Fi, etc.).
A technique that uses the transistor parasitics as active elements to reduce power converter switching losses.
A solenoid driver controls the current flowing into a solenoid device during its operation. The main advantage of using a driver consists in optimizing the solenoid current consumption, allowing for less power dissipation and heating of the device.
Serial peripheral interface. A four-wire, synchronous, full-duplex, single-master/multi-slave serial communication protocol based on a single- master/multi-slave architecture. The four lines shared between master and slave are: the SCLK (serial clock) where the master sets the communication frequency; the MOSI (master output/slave input) through which the master sends data to the slave; the MISO (master input/slave output) through which the slave sends data to the master; and the CS (chip select), used in multi-slave systems by the master to select which slave it wants to communicate with.
A proprietary Hall element-based sensing technique for angle measurement.
The stationary part of an electrical motor.
A buck converter, or step-down converter, is a switching power supply capable of producing a DC output voltage smaller in magnitude than the DC input voltage.
A boost converter, or step-up converter, is a switching power supply capable of producing a DC output voltage greater in magnitude than the DC input voltage.
A motor type whose manufacturing features allow it to perform small rotations (steps) and holds its position firmly. Widely used in applications that require high positioning precision.
Space vector pulse-width modulation. A modulation technique used in three-phase inverters. Widely used because it optimizes the voltage output, and lowers switching losses and harmonic distorsion.
Refers to AAM mode.
A switch mode power supply (SWPS) or switching voltage regulators involves semiconductor devices that operate at high frequency to convert electrical power in an efficient way.
A switching power converter that uses MOSFETs instead of a diode to achieve rectification functionality. This improves the efficiency, cost, thermal perfomance, and reliability of the power converter.
Permanent magnet used in angle sensing with a magnetic encoder to determine the angular position of a shaft.
A circuit added to the power converter to protect it when an over-temperature condition is reached.
The key element to guarantee electrical isolation.
Products that can operate within all normalized input scenarios.
Universal serial bus type-C.
Under-voltage lockout. A protection that makes devices turn off when the supply voltage goes below a certain threshold. In an under-voltage condition, components can have unexpected behaviors, and UVLO is used to avoid them being damaged.
Three signals used to commutate a three-phase brushless DC motor. Spacing of the signals informs the motor controller when to apply energy to each motor winding phase. Generated by three separate Hall sensors located in a brushless motor, or emulated and created by logic in a rotorary magnetic angle sensor.
Volts. The SI unit for voltage.
The valley of the inductor current is used to control the current limit of the power converter. The control MOSFET of the power converter cannot be turned on until the inductor current falls below the valley current limit threshold.
A backlight technology used in LCD displays that uses a matrix of LEDs to produce the light needed by the display. This technology allows for better images and thinner displays with a lower power consumption than older technologies.
The permanent voltage that can be withstood between isolated primary and secondary circuits over continuous normal operating conditions (tested per UL/IEC 60950-1).
Zero voltage switching is one type of soft-switching.
In a rotary magnetic angle sensor, refers to the programmable offset into the device such that manually aligning the sensor to the magnet poles is not required.
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