TPS7A3001DGNT thermal analysis

engr_joni_ee

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Hi,

I have looked at the datasheet of TPS7A3001DGNT. In equation (3) a formula is given for power dissipation.

[P][/D] = ( [V][/IN] - [V][/OUT] ) ( [/MAX] + ([V][/IN]) ( [/Q]))

What is ) [/Q]) ?

Sorry, there is a problem in writing equations here in the editor. If I click under the three dots there comes an option f(x), I guess this option is for writing equation but then it gives me an error that "We run into a problem. The requested page could not be found."
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Also, the equation (10) it says.

T_T is the temperature at the center-top of the device package.
T_B is the PCB temperature measured 1 mm away from the device package on the PCB surface.

Are these both temperatures (T_T and T_B) representing temperatures at power off state ?

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I wanted to this equation (3) but not able to correct it. There is something wrong in the editor.
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I manage to write equations in word document. I did some calculations. Kindly check and let me know if they are correct. I guess I do not need any heat sink.
 

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Last edited:

Hi,

Is it really asking too much for a link to the datasheet? .. or at least a screenshot of the detail you are asking about? (from a long term member, as you are)
It´s really time consuming and prone for misunderstandings and errors.

In equation 3.. there is no "Q" but there is "IQ".

IQ usually is the quiescent current.

I have to admit that the datasheet should use consistent abbreviations.
In the "Electrical Characteristics section" they specify: Ground current IGND.

--> use IGND instead of IQ in the formula 3. See figures 3...7.


Klaus
 

Sorry the problem was that I could not write "IQ" in the editor here. And I search for quiescent current but in the datasheet I find nothing for quiescent current. I see in Figures 3 to 7, the I_GND is in mA range and maybe ignore in calculations.

Here is the link to the datasheet.


I manage to write equations in word document. I did some calculations. Kindly check and let me know if they are correct. I guess I do not need any heat sink.
 

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Hi,

well done so far.

yes 0.12W is rather low power. No heatsink needed.

Klaus
 

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