multilayer varistor (MLV)

Multilayer varistors (MLV) are used for electrostatic discharge(ESD) suppression. Generally, varistors belong to the voltage-dependent resistors, which have a high resistance at low voltages and a very low resistance at high voltages.

Multilayer varistors are made of ceramic material that is sufficiently resistant to electrostatic discharge. They are composed of thin layers ofzinc oxide( ZnO) mixed with other metal oxides. The ZnO layers are sandwiched between metal plates that form the two electrodes to which the leads are connected. The voltage- current behavior of multilayer varistors is nonlinear. Their breakdown voltage can be less than 5 V.

Multilayer varistor (MLV), structure and SMD design

Multilayer varistors have extremely low capacitance and can dissipate discharge voltages of several hundred volts at capacitances of about 1 pF. Due to the low capacitance, they react in a few nanoseconds. The dischargeable pulse current can exceed 1,000 A. The multilayer varistors offered on the market are designed as SMD components and can be soldered directly onto the circuit board.

A further development of the multilayer varistor is the metal oxide varistor( MOV).