DCDC switcher without thermal shutdown

Fubin,

MC34063A

Ronald,

Thanks for the quick reply. Is there a list of these devices that I can pick from? Or more devices that you know of that might be able to survive above the normal thermal shutdown temp.

Thanks,

Fubin

Fubin,

I am not aware of a list. 

Just to be clear; the MC34063A does not protect itself from temperature. That is not the same as saying the part survives the abuse.

Adding an external switch (to lower internal heat) and having a slower oscillator (clock) will be helpful. 

I'm not aware of any list, but there are devices that are rated for high temperature operation.  Can you post your actual requirements?

You may also want to check out the TPS40200-EP and try posting in the high reliability forums. Link below.

http://e2e.ti.com/support/applications/hirel/default.aspx

Best Regards,
Anthony

I want to see what's available out there that I can test without paying the premium for the HT and hard to get parts.

Anthony,

Thanks, I am new to the forum and did not know that one. I posted the question here is that I only want to know what's available for DCDC switchers that do not have a thermal shutdown. I was not able to filter it out from the TI website. I guess a lot of apps here might know some devices that I can try out if they look promising.

Anyway, let me know if you know of any of these switchers, greatly appreciate it.

Even if you were to use a part with no thermal shutdown, you may not be able to operate it reliably above the maximum rated junction temperature.  Also, when the ambient temperature reaches the maximum junction temper, the device dissipation rating is 0 W.

I totally agree with you. But I also know some MAXIM parts that work fine at HT and rated only 85C on the specs. If I calculate the numbers the power dissipation will derate to negative. I understand some of the theory here. I could not believe it before I saw that.

I'd appreciate it if you could share more parts that do not have thermal shutdown. I will test some to find out if possible.