TPS1HB08-Q1: Query on Tj sense accuracy

Sri Viswa Sathiamoorthy

Part Number: TPS1HB08-Q1

Tool/software:

Query is for the PN TPS1HB08AQPWPRQ1:

I understand from the datasheet pg no 27, current proportional to Tj is calculated using below formula,

In the Tj sense characteristics below (datasheet pg no: 7), we can see that there is min and max value and the tolerance is not constant across temperature range. May I know which parameter in the above formula affects this?

Can we get a way to find the tolerance for temperatures intermediate between two temperatures (eg: 25C & 85C)?

Thanks,

Sri Viswa

11 months ago

0 Sarah Raines 11 months ago

TI__Expert 8100 points

Hi Sri,

Please use the worse accuracy of the two values for your calculations. In above example, 85C has a wider +/-% accuracy than 25C, so just choose those accuracy numbers to go with your chosen Tj.

Thank you,

Sarah

0 Sri Viswa Sathiamoorthy 10 months ago in reply to Sarah Raines

Prodigy 195 points

Hi Sarah,

Thanks for your response.

ISNST = (Tj - 25 ) * dIsns/dT + 0.85

In the above formula, i have two queries,

Whether 25C is the ambient temperature?
Which parameter this 0.85 indicates?

Thanks

0 Sarah Raines 10 months ago in reply to Sri Viswa Sathiamoorthy

TI__Expert 8100 points

Hi Sri Viswa,

This equation is a transfer function. The 0.85 is actually the 0.85 mA typical value at a junction temperature of 25C. This comes from the table in the "Tj Sense Characteristics" section.

Thank you,

Sarah

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TPS1HB08-Q1: Query on Tj sense accuracy