In a message dated 1/15/01, John Juhasz writes:
> I am trying to find a second-source for a TVS (Transient Voltage Suppressor) > that I now use to meet the 61000-4-5 1.2/50us 1kV transient. > Hi John: To finalize the requirements on the surge suppressor you need, you will have to determine the short circuit current of the surge, the required standoff voltage of the TVS device, the required clamping voltage, and the allowable capacitance. With these parameters in mind, some vendors to consider are Teccor (http://www.teccor.com), ST Microelectronics (http://www.st.com), and Semtech (http://www.semtech.com). All of these vendors have some very nice surface mount "crowbar" type devices, some of which are in packages common to two or more vendors. For instance, the Teccor sidactor in the DO-214 package is similar to some ST Microelectronics parts. If the surge is not very high energy, you could also consider using surge suppressor zener diodes such as the devices in the SMA, SMB, and SMC packages that many manufacturers of discrete components make. Some of these can handle up to 1500 watts for one millisecond. Motorola (now On Semiconductor, http://onsemi.com), General Semiconductor (http://www.gensemi.com), and Central Semiconductor (http://www.centralsemi.com) all make these devices. Examples from the Motorola family of "600 watt" TVS diodes are the 1SMB series and the P6SMB series. For high energy surges, I prefer the crowbar type devices such as teh Teccor sidactor. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
