Power supply and DC-to-DC converter designers are faced with more and more electrical noise intrusion issues from nearby higher power systems. This and increasingly stringent EMC and power filtering requirements mean engineers must carefully identify electrical noise intrusion to power and signal lines that require common-mode and differential-mode filtering. In common-mode noise, the signals on the two lines are in phase with each other. This is often seen in signals with a ground connection where a noise current is developed in the ground path due to a parasitic capacitance between the cable and the ground. Common-mode current can create high-level voltage spikes that damage electronics or create EMI. In this case, common-mode chokes are employed. Often composed of a toroidal ferrite core wrapped with two independent coils of the same size and number of turns, common-mode chokes are four-terminal components that essentially insert a large inductance in series with common-mode sources. This significantly impedes common-mode noise while having minimal effect on the desired signal. Eaton’s common-mode through-hole (ECMT) and common mode surface mount (ECMS) family of chokes are ideal for noise attenuation over a wide range of frequencies up to 100 megahertz while reducing board size. The ECMT’s feature a metallization on the ferrite core that results in excellent shock resistance and damage-free durability for operation from -40 °C to 125 °C. A closed magnetic circuit design reduces leakage flux and EMI, while the iron-based core provides a large saturation current. The ECMTs come in five through-hole sizes, offer inductance values up to 85 millihenries, and enable automated production with tray packaging. The ECMS are high frequency, magnetically shielded filters that come in three surface mount sizes and are footprint compatible with other commonly used common-mode chokes. With a low DC resistance and impedance values from 70 Ohms to 3,000 Ohms. These common chokes offer a high current capability of up to 15 Amps allowing for use in high-powered signal lines. Between the ECMT and ECMS, Eaton’s family of common-mode chokes offer a complete range of filtering options with high current ratings, a wide range of impedance values, and high inductance values.
Eaton’s new MFBA2V family of high-reliability AECQ automotive grade surface mount ferrite beads are ideal for noise reduction in automotive applications including electronic control units, powertrains, body controls, and multimedia.
These multilayer ferrite beads are available in 10 unique impedance values from 30 to 600 Ohms and with DC resistance values as low as 30 milliOhms. They are uniquely designed to minimize high-frequency electrical noise in EMI-sensitive applications.
And, with support for operating temperatures from -55 °C to +150 °C, the Eaton MFBA2V series can stand up to harsh automotive environments while supporting rated currents as high as 4 Amps.
These compact SMT chip beads are available in three industry-standard sizes: 1005, 1068, and 2012.
The MFBA2V ferrite beads feature a rugged multilayer construction with proprietary noise-suppression materials. They are manufactured using world-class quality standards to meet AEC-Q200 certification, moisture sensitivity level 1, and are REACH and RoHS qualified.
Eaton presents their SCF series of self-control, triggerable fuses. These multi terminal fuses provide both overcurrent and overcharging protection for single and multi-cell battery applications . An integrated thermal element provides triggerable operation from an external FET or IC during an overcharge condition and a traditional fusible element offers fast-acting performance for short circuit protection. The SCF fuses are available in three different surface mount packages where the SCF4030, the SCF5432, and SCF9550 support up to 10, 14, and 24 applicable cells in series. The fuses are both RoHS-compliant and halogen-free with current ratings from 12 amps up to 45 amps and operational voltages up to 80 VDC. The self-control fuses are suitable for battery-powered electronics such as notebook and laptop computing, handheld electric power tools, and battery powered household appliances.
Eaton’s TV family of supercapacitors operate at higher voltage to reduce the number of cells and size needed in high voltage designs or keep the same number of cells to do more with higher energy storage. They provide energy storage for high power charge/discharge cycling, peak power shaving and backup power applications. They also provide power to safely shutdown systems and avoid data loss when main power is disconnected. TV cells are RoHS compliant, UL recognized, and contain no heavy metals. They can operate temperatures from -40 °C to +85 °C.
Eaton‘s MPIA product line is the latest advancement in low profile power magnetics designed to meet automotive electronics highest power density and thermal handling requirements. The MPIA uses an advanced molded construction design for high current handling capabilities, better thermal dissipation characteristics and superior mechanical strength. The MPIA family consists of the MPIA20, MPIA25, and MPIA40, which each come in varying footprints, heights, current ranges, and inductance values. The combination of a compact low profile surface mount package, magnetic shielding for low EMI, low core loss, good temperature stability over the operating temperature, and an AEC-Q200 qualification makes these power inductors ideal for a wide range of automotive applications. These automotive use cases range from body electronics, advanced driver assistance systems, as well as infotainment and cluster electronics.
A Negative Temperature Coefficient thermally sensitive resistor, or NTC thermistor, exhibits a sharp decrease in resistance as temperature rises. Thermistors are ceramic semiconductors manufactured by sintering metal oxide compounds at high temperatures. Controlling the thermistor material composition makes it possible to adjust the material’s resistivity to determine the thermistor’s size and resistance so that the finished product is optimized for a range of applications. This characteristic decline in resistance over temperature is what makes this device ideal as a highly sensitive temperature sensor — the device can be formulated so that the most sensitivity occurs at different temperatures. An application with an ice cube maker would likely leverage the dark blue curve, since any small change in temperature below the 0 °C range yields a massive change in resistance. On the other hand, a coffee pot would require a thermistor with sensitivity in the range of temperatures that coffee is brewed; around 90 °C to 96 °C. Engineers can get an idea of this change in resistance over temperature from either the alpha coefficient, the beta relationship, a R-T lookup table, or the steinhart-hart coefficients. One of the more commonly used parameters is the beta value. This value uses the change rate in resistance between two given temperatures to provide a basic approximation of the resistance versus temperature response of an NTC thermistor. A smaller beta value will correspond to a lower sensitivity within the temperature span, while a larger beta value will have a higher sensitivity within the specified temperature differential. Discrete NTC thermistors can either come in a surface mount, bare chip with silver or gold metallized ceramic. Lead-in devices can either be in a radial or axial lead configuration. Glass encapsulated thermistors offer the most ruggedization with operating temperatures up to 300 °C and much higher long-term stability at high temperatures. Epoxy or polyimide encapsulated discrete NTC thermistors have operating temperatures up to 125 °C but are a cost-effective option.
Eaton offers a lineup of NTC thermistors that are optimized for a range of functions from temperature measurement to temperature compensation in an array of applications. The lineup of thermistors consist of the glass-sealed NDBG and NRBG, resin-sealed NRBE, NRM, and NRL thermistors as well as the printed circuit board surface mount NTC thermistors. The axial NDBG and radial NRBG series of glass-sealed thermistors both feature high reliability heat resistance with temperature ratings above 200oC and are optimized for household and commercial appliances, solar energy systems, and industrial applications such as intelligent fire systems. The resin-sealed, radial NRBE, NRL and NRM series axial NTC thermistors feature a smaller size and faster thermal response making them ideal for temperature measurement for safety devices, office automation equipment, and home appliances. The NT family of surface mount NTC thermistors are helpful for miniaturizing circuits. The NT series is ideal for temperature compensation and available in footprints from 0402 up to 0805
Eaton offers its AMLV series of automotive chip varistors to expand on its commercial MLV offerings and to complement its automotive, high reliability circuit protection portfolio. Used for automotive transient voltage and electrostatic discharge protection, AMLV varistors provide excellent ESD suppression and electrical transient conduction in accordance with ISO standard 7637-2. Automotive MLVs are offered in 7 industry standard surface mount package sizes to help protect integrated circuits and components at the board level. The multilayer chip construction enhances solderability and manufacturability in automotive systems. The AMLV series is AEC-Q200 qualified and RoHS and Halogen Free compliant. This series meets environment reliability tests for temperature cycling, moisture resistance, biased humidity, operating life, shock, vibration, and more. The AMLV series of chip varistors have working voltages up to 56 Volts DC and 40 Volts AC, a maximum clamping voltage as high as 110 Volts at 1 Amp, and a peak current of up to 1,200 Amps. Eaton offers an MLV product option to meet the requirements of every automotive application.
Eaton offers MOVTP thermal protected Metal Oxide Varistors. These varistors are ideal for protection of sensitive components at the circuit board level, providing protection against surges and transients from events such as lightning, power contact, and power induction. The combination of the metal oxide varistor with a thermal fuse element allows the MOVTP to protect circuits from over-voltage transients while also preventing the device from reaching thermal runaway in the event of a sustained over-voltage event. Electrical specifications for the MOVTP include working voltages from 170 to 615 Volts DC and from 130 to 465 Volts AC. They are available in 14 mm and 20 mm diameter discs and can withstand peak surge currents from 6,000 to 10,000 Amps. The MOVTP varistors from EATON are radial leaded devices and come in two or three pin configurations where the integrated third lead can be used to generate an alarm signal during transient events or product end of life.