The TDA7492 is a dual BTL class-D audio amplifier with protection and diagnostic output. What are the thresholds for triggering the diffrent protections in particular open circuit

[JHedg.1]

Im looking to find the threshold limit of Open Circuit protecion of an output channel, ive looked in all the datasheets but im sure it was around 1K ohm but i cant find a value anywhere. Does anyone know where i can get this data?

Thanks

James

[Peter BENSCH]

Welcome, @JHedg.1​, to the community!

What do you mean by Open Circuit Protection in the context of a Class-D amplifier?

With the TDA7492 there are several protections, maybe you meant OCP, which is Over Current Protection?

Regards

/Peter

[JHedg.1]

hi peter, Thanks for coming back quickly. No i meant open circuit, as in if a drivers voce coil is higher impedance. I know the datasheet specifies OC, I just need to make sure if i dont have a standard load on the output it will not flag an error. I dont think there is as when ive tested, the amp runs regardless.

Im having to use the output to derive a signal and im trying to avoid a large load as its going to wastful in power and heat, so i want to use the smallest load i can to keep the amp happy so i can get my signal and not trigget any diag out put.

Hope this makes sense

thanks

james

[Peter BENSCH]

Where in the data sheet did you find a statement about OC in connection with Open Circuit?

Regards

/Peter

[JHedg.1]

i dont think it was in this chip, it was in another version. i just need to make 100% sure. Its for an automotive application and i cannot trigger diag and cause an error on the can bus.

[Piranha]

You are confusing the "open drain" for DIAG output pin with some protection, which doesn't exist, because there is no need for it.

And what do you mean by "large load"? If you think that a higher resistance is a "larger load", then you should start actually start learning electronics by learning the basics:

https://en.wikipedia.org/wiki/Ohm's_law

[JHedg.1]

i understand fully about the load being large is a smaller value and i am not mis understanding the diag out put as thats just to drive an input to what ever system

thanks for your input

[JHedg.1]

ive been told by the auto manufacturer they get a diagnostic output if the loudspeaker goes open circuit or higher impedance. i cant find anything about this so i am just checking here to make 100%. Please dont assume what i do and do not know and patronise. im just asking a question. to make 100% sure.

[Piranha]

First you ask for a nonexistent threshold limit for a TDA7492, then you say that it's for a different chip, but didn't say the part number. Now you want to assure... What exactly?

And what's the problem in reading the TDA7492 datasheet section "6.6 Protection functions"?