dipnirvana
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Hi i have very basic/fundamental question !
We design product for CE certification . That includes surge requierment (IEC 61000-4-5). If we look at the standard it safecify pulse voltage , source resistor , timing at 25degC . The satndard also talks of some variation , too.
It's easy to design for 500V/2 ohm surge with all this variation and a 3kW SMD TVS will fit . But if take temprature rise in actual field condition and assuming same level of surge will come there , non of SMD TVS will fit there . As , TVS has large temprature dertaing as high as 50% at elevated temprature of 80degC.
The question is "does it correct to consider same surge voltage level/resistance at higher temprature " ? Second question is " Is it right to design only at 25degC and not for higher temprature as defined by the satndards "
Thanks in advance .
We design product for CE certification . That includes surge requierment (IEC 61000-4-5). If we look at the standard it safecify pulse voltage , source resistor , timing at 25degC . The satndard also talks of some variation , too.
It's easy to design for 500V/2 ohm surge with all this variation and a 3kW SMD TVS will fit . But if take temprature rise in actual field condition and assuming same level of surge will come there , non of SMD TVS will fit there . As , TVS has large temprature dertaing as high as 50% at elevated temprature of 80degC.
The question is "does it correct to consider same surge voltage level/resistance at higher temprature " ? Second question is " Is it right to design only at 25degC and not for higher temprature as defined by the satndards "
Thanks in advance .