SN75ALS181: Min/Max Junction temperature

Nam, Dino

Part Number: SN75ALS181

Dear team,

The operating free air temperature of SN75ALS181 is 0 to 70. But the customer want to know operating junction temperature range(Min/Max value).

Please let me know Tj(Operating junction temperature range) value.

Thank you.

over 8 years ago

0 Matt Mendez over 8 years ago

TI__Intellectual 2885 points

Hi Dino,

I've looked over the datasheet, and on page 4, there is a note under "Absolute Maximum Ratings" that notes the MAX Operating Junction Temperature is 150 C. I'll have to look further for the Min value.

0 Nam, Dino over 8 years ago in reply to Matt Mendez

TI__Expert 6445 points

Hi Matt,

Thank you for your reply. I am sorry to push you but the customer want to know the Min Operating junction Temperature also. please let me know Min value.

Thank you.

0 Matt Mendez over 8 years ago in reply to Nam, Dino

TI__Intellectual 2885 points

Hi Dino,

I calculated the minimum operating junction temperature, it is 12 C. I referenced this document section 1.1

TJ = TA + (RΘJA * Power)

Power = VCC * ICC = 5 V * 0.30 mA = 0.15 W

TA = 0 - 70

RΘJA = 80 or 76 (selected 80, for worst case scenario)

TJ = 0 + (80 * 0.15) = 12 C

0 Matt Mendez over 8 years ago in reply to Matt Mendez

TI__Intellectual 2885 points

Hi Dino,

I made a mistake in the calculation. And I have talked with some engineers and they have pointed out that using the VCC and ICC is not a reliable way to measure the operating junction temperature. In general, minimum power ratings are not specified in datasheets. Thus equating minimum ambient operating temp to the minimum operating junction temperature is perfectly OK.

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SN75ALS181: Min/Max Junction temperature