TVS Diodes
WORLD PRODUCTS INC. 19654 Eighth Street East, Sonoma, CA 95476 | Phone (707) 996-5201 | Fax (707) 996-3380 | www.worldproducts.com Rev. 6.4
2 | TVS Diodes
General Information
TVS Diode Technology
World Products Transient Voltage Suppression (TVS) Diodes are silicon avalanche devices designed, manufactured,
specied and tested according to voltage suppression applications.
These devices, with their fast response and low clamping characteristics, protect all MOS technology based devices,
hybrids, and other voltage sensitive components. The low clamping factor and pico-second response time of World
Products TVS Diodes clamps transient pulses early and maintains them at an acceptable level for their entire duration. In
other overvoltage protection devices, response times are delayed by 24nS to 2μs allowing transients to reach dangerous
levels. World Products TVS Diodes are designed to meet a 1.30 maximum clamping factor at their rated peak impulse
current. This can be compared to clamping factors of 2 to 5 found in other protection devices.
TVS Diode Applications
TVS Diodes are the optimum choice in protecting computer or data processor circuits and power supplies, airframe
avionics and controls, numerically controlled machines, telecom circuits, and many other applications. These devices
are designed to protect against transient voltages generated by lightning, electro-static discharge (ESD), and inductive
switching.
TVS Diode RoHS Compliance
All axial TVS Diodes (no sufx code required) and SMD TVS Diodes (denoted by sufx “F”) products purchased from
World Products, LLC comply to a maximum concentration value of 0.1% by weight in homogeneous materials for lead
(Pb), mercury, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE) and of
0.01% weight in homogeneous materials for cadmium and are in compliance with Directive 2002/95/EC of the European
Parliament and of the Council of 27 January 2003 on the restriction of the use of certain hazardous substances in
electrical and electronic equipment (RoHS Directive).
Note: Lead(Pb) in high-melting point solder for internal connections is not inhibited by RoHS. (i.e. tin-lead solder alloys
containing more than 85%)
Selecting the Correct Part Type
The following guidelines should be observed in selecting the correct diode:
TVS Parameters Application Parameters
1. Stand-off Voltage (Vwm) >= Operating Voltage (Vop)
2. Peak Pulse Current (Ippm) >= Source Transient Current (Is)
3. Clamping Voltage (Vc) =< Voltage Withstand (Vws)
1. If the stand-off voltage is less than the operating voltage of the application, the diode will continually clamp the
circuit voltage.
2. The Peak Pulse Current (Ippm) is the maximum current the TVS can handle. The source transient current is
determined by dividing the peak transient voltage by the source impedance — this is often difcult to determine. In
many cases, however, this may be obtained from industry standard documents, customer requirements, etc.
3. Determine the maximum voltage level that the protected device can withstand (Vws). Select a suppressor which will
clamp the transient at a lower level (Vc).
Consider the transient source: lightning, electro-static discharge, inductive switching or nuclear explosion (NEMP).
Often, a 1500 watt peak pulse rated device will protect against transients due to secondary lightning effects or inductive
switching on power, data and telephone lines. A 500 watt device is sufcient to protect sensitive components against
transients generated by electro-static discharge.