LM5068: Thermal Resistance of the IC

John Gray

Intellectual 310 points

Part Number: LM5068
Other Parts Discussed in Thread: LM5067

What is the thermal resistance of the LM5068.

Operating conditions indicate 105C max Tj.

Then ordering indicates operation Temperature is 105C max.

So I'm not sure what thermal resistance to give this part. Can anybody tell me what that is?

thanks,

-John

over 7 years ago

0 Aramis P. Alvarez over 7 years ago

TI__Genius 10370 points

Hi John,

The thermal resistance for RthetaJC should be approximately 44 C/W.

I do want to point out that the LM5067 is a MUCH BETTER choice than the LM5068. Here are some of the comparisons below:

The LM5068 does NOT have SOA protection (Power limit). LM5067 does have SOA Protection.
The LM5068 is less accurate with current limit (+/- 20% vs +/- 12%)
The LM5068 wastes more power (current limit threshold 100mV vs 50mV)
The price of the LM5067 is similar (in some cases cheaper) than the LM5068.

Our team always recommends the LM5067 when it comes to full protection for high negative voltage applications. I hope this helps :-)

Best Regards,

Aramis P. Alvarez

0 John Gray over 7 years ago in reply to Aramis P. Alvarez

Intellectual 310 points

Aramis,
Thanks for the answer on the thermal resistance.
Can you answer about the max Junction temperature? Is the 105 operation temp ambient, case or junction?

Thanks,
John

0 Aramis P. Alvarez over 7 years ago in reply to John Gray

TI__Genius 10370 points

Hi John,

Those values can be found on the "Absolute Max. Ratings" and the "Operating Ratings" on the LM5068 datasheet (look below for a screenshot):

Best Regards,

Aramis P. Alvarez

0 John Gray over 7 years ago in reply to Aramis P. Alvarez

Intellectual 310 points

Thanks Aramis, I guess that was in plain sight.
-John

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LM5068: Thermal Resistance of the IC