BTA16 vs BTA20

[DaniES]

Hi all,

We have an application of an electric heating boiler using BTA16 triacs to commute resistive loads of 13A (rms). The max. temperature in the triacs is around 70ºC-80ºC.

We are studying the option of using the BTA20 triac instead of the BTA16 one to improve the reliability of the solution. Both use the same case. I have checked the curves "On-state rms current versus case temperature" in the data sheet of both references and the behaviour in terms of max. current supported with 70ºC-80ºC case temperature seems equivalent because the BTA20 max current starts to decrease from 70ºC on while the BTA16 starts to decrease from 85ºC on. The scale of the graphs (in the attached) does not allow me to confirm which one would support more current. Could you please help me with this?

In addition, I have seen the maximum power dissipation versus on-state RMS current graphs. It seems than the BTA20 max power dissipation is higher than the one in BTA16. Does this mean that under the same environment, the BTA20 is able to dissipate more heat, and therefore reduce the case temperature?

Thanks in advanc

[Peter BENSCH]

As both triacs have the same package and therefore the same thermal resistance, and generally the same on-state voltage VTM, this voltage will cause the same power loss and therefore the same temperature differences in the same environment (heat sink, etc.). In this respect, nothing changes as a result of the replacement if the environment remains unchanged (as long as the gate current is identical, otherwise the required control changes). Only the margin in the event of a possible short-term overload would be greater with a BTA20 compared to a BTA16.

Hope that helps?

Regards
/Peter