TDA7297 - temperature. According to datasheet "Top operating temperature" of TDA7297 is in range "0 - 70 st.C". However junction temperature is "-40 to 150 st.C". So it is possible for this amplifier to work in -40 temp. environment?

wozniakm19 · ‎2022-01-26

Peter BENSCH · ‎2022-01-27

OK, I'll try to simplify it again:

Operating Temperature aka Operative ambient temperature

Applies when the component is installed in an application circuit and is currently operating.

In this case, the parameters specified in the data sheet under Electrical Characteristics are guaranteed (provided the remaining ambient conditions are also within the permissible range). This is therefore the permissible operating range.

Storage and Junction Temperature:

Are considered to be a statement of what temperature the component will survive, which has absolutely nothing to do with function or with maintaining parameters under that condition.

Specifically:

TDA7297
- Top: 0 to 70 => Electrical Characteristics guaranteed
- Tj: -40 to 150 => TDA7297 survives in this range

TDA7376B.
- Tamb: -40 to 105 => Electrical Characteristics guaranteed
- Tj: -40 to 150 => TDA7376B survives in this range

If the problem is resolved, please mark this topic as answered by selecting Select as best. This will help other users find that answer faster.

Regards

/Peter

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wozniakm19 · ‎2022-01-26

So it is possible for this amplifier to work in -40 temp. environement (it is not possible to

achieve that temperature by junction /heating/)?

Peter BENSCH · ‎2022-01-26

The Operating Temperature is the temperature for which a function of the respective component is guaranteed by ST. This does not necessarily mean that the component will not function outside this range, it is just not guaranteed.

So if a problem occurs, for example your device doesn't work at all or doesn't work properly or that it explodes (just kidding), then this is the responsibility of the developer of this device.

Regards

/Peter

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wozniakm19 · ‎2022-01-26

I am still not understand it.

If operating temperatur (0 - 70 st.) is max why thermal overload protection is set to 150 st?

Also why min. operating temp. is 0 if junction temperature (which is also referring to working IC by definition) is -40? Especially it confuses me because it is no possible to obtain lower junction temperature than operating/ambient temperature?

Peter BENSCH · ‎2022-01-26

The thermal overload protection is at 150°C to avoid destruction of the chip. The values given under Storage and Junction Temperature also refer to the fact that destruction can occur outside this range.

The Operating Temperature, as I have already written, refers to the range where the function of the TDA7297 is guaranteed.

Summary: If

the TDA7297 is operated in the temperature range 0-70°C and
it is ensured that the junction temperature is between -40...+150°C (whereby it is clear that only the maximum value is relevant here), furthermore
the electrical parameters are observed, then its function is guaranteed.

If one of these conditions is violated, the function is not guaranteed and the responsibility is on your side.

Hope its clear now?

Regards

/Peter

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wozniakm19 · ‎2022-01-26

I would ask for definition (referring to a datasheet) of Top (operating temperature). It is identical as ambient temperature?

Peter BENSCH · ‎2022-01-26

Yes, the operating temperature range can be read as the ambient temp.

Regards

/Peter

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wozniakm19 · ‎2022-01-26

So I am not sure it is clear:

"If one of these conditions is violated, the function is not guaranteed and the responsibility is on your side."

E.g. let's take two theoretical cases:

1) Operating/ambient temperature (Top): 0 deg.

Junction temperature: -40 deg.

None condition is violated. Function is guaranteed.

2) Operating/ambient temperature (Top): -40 deg.

Junction temperature: -40 deg.

Function not guaranteed (condition Top violated).

But how it can affect functionality if junction temperature defined as internal semiconductor structure has same temperature?

Best Regards,

Marcin

Peter BENSCH · ‎2022-01-26

As you said, this is a purely theoretical discussion: a junction temperature of -40°C is not practical at an ambient temperature of 0°C.

As long as you don't specify what you want to achieve with this discussion, nobody can help you.

Regards

/Peter

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wozniakm19 · ‎2022-01-26

I want to know if TDA7297 can operate with junction temperature -40 to 150 degree of Celsius.

If yes what is the purpose of giving max. temperature operation for 0 to 70 degree.

I think it is some kind of bug/wrong definition used in this datasheet and I want to confirm it.

Please instead see datasheet of TDA7376B.

Tambient: -40 to 105.

Tjunction: -40 to 150.

It is pretty clear and logical here. Ambient/operating temp. have to be lower to have physical possibility dissipate heat from junction.