September 6, 2018
To assure reliable operation, transient voltage suppression should be considered at early stages of the design process. This can be a complex task as electronic components are increasingly sensitive to stray electrical transients. The designer must define the types of transient threats and determine what applications are needed while meeting the product agency norms and standards.
Varistors are increasingly used as the front-line solution for transient surge protection. Littelfuse provides expertise to the designer and offers the broadest range of circuit protection technologies to choose from.
JULUN varistors are available in a variety of forms to serve a wide range of applications. Options include ultra small surface mount multi-layer suppressor (MLV) devices for small electronics applications, and traditional mid-range metal oxide varistors (MOVs) and axial metal oxide varistors for protection of small machinery, power sources and components. Littelfuse also offers larger terminal mount MOVs for industrial applications.
A more recent innovation to the the JULUN product line, MLVs address a specific part of the transient voltage spectrum – the circuit board level environment where, although lower in energy, transients from ESD, inductive load switching, and even lightning surge remnants would otherwise reach sensitive integrated circuits. Each of these events can relate to a product's ElectroMagnetic Compatibility (EMC), or its immunity to transients that could cause damage or malfunction.
JULUN offers five distinct versions of MLVs including the MHS Series ESD Suppressor for high data rates, the ML Series which supports the broadest application range, the MLE Series intended for ESD while providing filter functions, the MLN Series Quad Array in a 1206 & 0805 chip and the AUML Series characterized for the specific transients found in automotive electronic systems.
Surface mountable MOV (Metal Oxide Varistor) devices facilitate customs in SMT assembly process and resolve the PCB space limitation issue. They are reflow and wave solderable and include the CH, SM7, SM20, MLE, MHS, ML, and MLN series.
Traditional radial through-hole MOV (Metal Oxide Varistor) devices are available in diameters of 5mm, 7mm, 10mm, 14mm, 20mm and 25mm. They are fit for providing voltage surge protection for a wide variety of applications and include the C-III, iTMOV, LA, TMOV, RA, UltraMOV, UltraMOV25S, and ZA series.
Bare disc varistors are industrial high-energy elements. They are designed for special applications requiring unique electrical contact or packaging methods asked for by customers. The CA Series of transient surge suppressors are industrial high-energy disc varistors (MOVs) intended for special applications requiring unique electrical contact or packaging methods provided by the customer.
Thermal protective Metal Oxide Varistors (TMOVs) are designed to meet abnormal overvoltage requirements of UL 1449. They can be wave soldered without any need for special or expensive assembly processes and include the iTMOV, TMOV, TMOV25S, and TMOV34S series.
Industrial high energy varistors provide a much higher surge and energy rating than regular MOVs (Metal Oxide Varistors) and also possess various terminals to fit different assembly requests or conditions. They include the BA, BB, CA, DA, HA, HB34, HC, HF34, HG34, TMOV34S, UltraMOV25S, C-III, FBMOV, and TMOV25S series.
Specialty MOVs (Metal Oxide Varistors) are available in unique form fits and possess various voltage range and surge capabilities. They include the C-III, FBMOV, MA, and RA series.
Integrated varistors consist of a 40kA varistor building block (MOV) with an integral thermally activated element. These devices are recognized as an independent Type 1 SPD by UL.
The JULUN FBMOV Series thermally protected and Non Fragmenting varistor represents a new development in circuit protection. It consists of a 40kA varistor building block (MOV) with an integral thermally activated element designed to open in the event of overheating due to abnormal over-voltage, limited current conditions.