TVS diode Basics
This page covers TVS diode basics.It mentions TVS diode application note and TVS diode manufacturers or Vendors.
The TVS diodes are solid state pn junction devices. They are specifically designed in order to protect sensitive semiconductors. The figure-1 mentions TVS diode symbols.
Surge power as well as surge current of TVS diode depend on junction area. Larger the cross section area of the TVS diode, higher is the absorbing capacity to absorb transient currents.
The major difference between TVS diode and zener diode is that TVS diodes are designed to suppress transient voltage while zener diodes are designed to regulate voltage.
Let us understand how TVS diodes work with example of application note mentioned below in which TVS diode is used to protect the circuit.
TVS diode Application Note
In normal operating conditions, TVS diode will introduce high impedance to protected circuit. In the condition when normal voltage exceeds, TVS diode junction avalanches and inserts low impedance path for the transient current.
Due to this transient current is deviated away. Hence circuit is protected. Voltage across the circuit is limited to TVS diode clamping voltage. After the transient threat vanishes, diode device returns to high impedance state.
The major benefits of using TVS diode is that the device does not wear out. Moreover there will not be any degradation in its electrical parameters. TVS diodes in wide range of voltages are available. Typically the diodes are available from 5 Volt to 440 Volt.
They are used as board level protectors for semiconductors as well other sensitive parts. The applications of TVS diode include MOS memory, AC power lines, signal and data lines, telecommunication equipments etc.
Recently Littelfuse Inc. has launched 6 new series of highly reliable TVS diodes. These diodes are used for aerospace applications.
As mentioned TVS diodes are mainly used for protection applications. These diodes will protect sensitive electronic equipments from lightning surges as well as unwanted voltage transients.
TVS diode Manufacturers/Vendors
Following are popular TVS diode manufacturers/vendors:
• Semtech Corporation
• ON semiconductor
• Littelfuse Inc.