Multilayer varistors
About the multilayer chip varistor
Varistor stands for Variable Resistor.
It’s a voltage nonlinear resistor/voltage-dependent resistor which changes resistance value depending on applied voltage.
It is a ceramic electronic component and it's used to protect electronic equipment from the abnormal voltage, such as ESD (Electrostatic) and surge.
Characteristics:
- Achieve ESD protection excellent effect by own ceramics materials and process technology.
- It is possible to replace from the Zener diode, which contributes to reducing the size and weight of the equipment.
- The wide product line up of the laminate structure and applicable to wide range of applications from high-speed signal lines to the power supply.
Voltage vs. current
Varistors' voltage/current characteristics are different from a normal fixed resister and resistance value is changed by applied voltage widely!
What is the function of multilayer varistor?
Current-Voltage characteristics
Multilayer varistors protect electronic equipment from ESD (electrostatic discharge) by utilizing the characteristics of changing resistance values depending on applied voltage!
ESD suppression mechanism
- Invading ESD into equipment.
- The resistance value of Varistor decreases rapidly by applied voltage exceeding varistor voltage.
- Varistor bypasses excessive current to a GND.
- Suppress ESD voltage and protect IC.
ESD suppression effect (example)
Multilayer varistors have excellent ESD suppression effect.
Types and applications of ESD countermeasure components
Multilayer Varistor is mainly applied to general signal circuits and automotive ECU; it can be applied to various devices.
Application example: Smartphones
Multilayer varistor is used in small electronic devices, TVs and AV equipment, including smartphones as a countermeasure component for ESD from the human body.
Application example: Automotive equipment (ECU)
Multilayer Varistor is applied to general signal lines and power lines of automotive equipment.
- ECU for body
(Size 0402 / DC30V / V1mA 42V / 56pF max.) - LAN communication lines (CAN, LIN)
(Size 0402 / DC16V / V1mA 27V /20pF max.) - Car navigation system
(Size 0402 / DC16V / V1mA 27V / 20pF max.) - Back monitor camera
(Size 0603 / DC16V / V1mA 27V / 100pF max.) - Power seat
(Size 0603 / DC16V / V1mA 27V / 20pF max.) - Keyless entry device
(Size 0402 / DC11V / V1mA 18V / 150pF max.)
