AEC-Q200 ZnO-Based Multilayer Varistor Transient Voltage Suppressors

AVX Corporation released what the company claims to be the industry's first multilayer varistor (MLV) transient voltage suppression (TVS) components rated for 175°C operation. According to AVX, the new TransGuard® VT Series of high-temperature MLVs provide extremely reliable bidirectional over-voltage protection across operating temperatures from -55°C to 175°C with zero derating.

Typical applications for the MLVs include underhood automotive applications, downhole drilling, and other uses with temperatures up to 175°C.

The MLVs are qualified to AEC-Q200, and are currently available in compact, surface-mount 0603 and 0805 case sizes. They also reduce the need for discrete MLCC capacitors as a result of some broadband EMI filtering in their off state, which further extends their usefulness into sensitive automotive circuits. AVX asserts that reducing the need for MLCC capacitors is especially beneficial considering current market-wide MLCC supply shortages.

They offer both bi-directional over-voltage protection and EMI/RFI attenuation in a single SMT package. This lets designers combine the circuit protection and EMI/ RFI attenuation function into a single highly reliable device, AVX says.

The new series of MLVs extends to circuit protection for other markets as well. The devices offer high current and energy handling capabilities and feature low leakage current. They also have multi-strike capabilities per IEC 61000-4-2.

TransGuard MLVs are zinc oxide (ZnO) based ceramic semiconductor devices with non-linear, bi-directional voltage-current (V-I) characteristics similar to those of back-to-back Zener diodes.

However, they have greater current and energy handling capabilities and they add EMI/RFI attenuation functionality.

The new VT Series MLVs extend the temperature range of over-voltage protection beyond the TransGuard portfolio's previous maximum of 150°C, AVX says.

(Click on table to enlarge)

Features

• Operating Temp.: -55 to +175°C
• Working Voltage: 18Vdc, 31Vdc
• +175°C rated, with no derating
• High Reliability
• AEC Q200 Qualified
• Bi-Directional protection
• EMI/RFI attenuation
• ESD rated to 25kV (HBM ESD Level 6)