KYOCERA AVX has extended its TransGuard VT Series with multilayer varistors designed for 48V automotive power systems, where higher bus voltages and dense electronics increase exposure to transients. The new variants focus on handling load dump, ESD, and switching noise in platforms ranging from mild hybrid vehicles to smaller electric mobility systems. The TransGuard VT Series 48V MLVs are zinc oxide-based multilayer varistors used for transient voltage suppression and EMI/RFI attenuation in automotive and industrial power lines. They are intended to sit across supply rails or at key nodes in the power path, clamping voltage spikes and absorbing surge energy before it reaches sensitive electronics.
The new additions are rated for operation up to 150°C and are qualified to automotive standards including AEC-Q200 and VDA-320. They are built for use on 48V rails, which are becoming more common in vehicle subsystems where higher power delivery is needed without moving to full high-voltage architectures.
Transient Protection For 48V Automotive Rails
Moving from 12V to 48V changes the stress profile on protection components. Higher nominal voltage leaves less margin before components see damaging spikes, particularly during load dump events, motor switching, or jump start conditions. The new TransGuard VT parts are designed with working voltages up to 56VDC and clamping levels in the 100–110V range, placing them within the expected transient envelope of 48V systems.
They also support multi-strike capability, allowing them to absorb repeated transient events rather than acting as single-event protection devices. That matters in automotive environments where spikes are not isolated events but part of normal system behavior.
High-Temperature Operation Without Derating
The TransGuard VT Series has been positioned for high-temperature environments, with operation extending from -55°C to +175°C for the wider family and up to 150°C for the new 48V-specific parts. KYOCERA AVX specifies zero derating across the temperature range, which simplifies component selection in systems exposed to sustained high ambient or localized heating.
This is relevant in areas such as engine bays, power distribution modules, and charging systems, where temperature cycling and elevated operating conditions are expected. The devices are also qualified to IEC 61000-4-2 and ISO 10605 for ESD performance, supporting their role in protecting exposed or user-accessible systems.
Electrical Characteristics And Energy Handling
The new 48V MLVs are available across standard EIA case sizes from 0805 through 2220, giving designers flexibility in placement and energy handling capability. Current handling ranges from 30A to 1,500A, with transient energy ratings between 0.2J and 9J. Capacitance values span 80pF to 2,800pF, which allows some tuning between transient suppression and signal integrity depending on where the device is placed. The parts are rated for 48V jump start conditions and can handle both AC and DC transient sources. Low leakage behavior helps limit continuous losses on the line, which is relevant for systems that remain powered for extended periods.
Mechanical Reliability And Integration
Some TransGuard VT Series parts, including selected 48V variants, are available with FLEXITERM terminations. These are designed to tolerate mechanical board flex and vibration, with capability for up to 5mm board flexure and extended temperature cycling beyond standard AEC-Q200 requirements.
From a layout perspective, the multilayer construction allows these devices to replace combinations of discrete suppression and filtering components in some designs. By combining transient suppression and EMI attenuation in a single package, they can reduce component count and free up board space in dense automotive modules.
The full TransGuard VT Series spans case sizes from 0603 to 2220, with working voltages from 12V to 56VDC and clamping voltages up to 110V. The new 48V devices extend that range into systems where higher bus voltages and tighter integration are becoming more common.
View the TransGuard VT Series datasheet
Learn more and read the original announcement at www.kyocera-avx.com
Technology Overview
The KYOCERA AVX TransGuard VT Series 48V MLVs are zinc oxide multilayer varistors designed for transient suppression on 48V power rails, with working voltages up to 56VDC, clamping at 100–110V, and current handling up to 1,500A. They operate from -55°C to +150°C, support 0.2–9J transients, and are qualified to AEC-Q200 and VDA-320.
Frequently Asked Questions
Where are 48V multilayer varistors used in automotive systems?
They are typically placed across 48V supply rails or near sensitive electronics to clamp voltage spikes caused by load dump, motor switching, and ESD events.
What temperature range do the TransGuard VT Series 48V MLVs support?
The 48V-specific devices are rated for operation up to 150°C, with the wider VT Series supporting up to 175°C depending on variant.
Do these MLVs replace other protection components?
In some cases, they can replace combinations of transient suppression and filtering components by providing both overvoltage protection and EMI attenuation in a single package.
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