TPL7407L the graph of D package Maximum Collector Current vs, Duty at 50deg

Shinichi Inoue

Guru 19671 points

Dear Specialists

My customer is considering TPL7407LD(SOIC).

He wants to know that the graph of D package Maximum Collector Current Vs. Duty at 50degC.

the datasheet has Figure 5. D Package Maximum Collector Current Vs. Duty Cycle at 25°C and Figure 6. D Package Maximum Collector Current Vs. Duty Cycle at 70°C

Because he can't accept the data of 70°C, because the data is over the maximum current of graph.

Best regards,

over 9 years ago

0 Ron Michallick over 9 years ago

TI__Guru*** 139956 points

Shinichi-san,

Power dissipation is I^2*R and 50C is 25C/45C (56%) between 25C and 70C.
sqrt(50C_current) is sqrt(25C current) + 56% * (sqrt(70C_current) - sqrt(25C_current) )

For example, for 7CH, 100% 25C = 225mA and 70C = 165mA.
50C current would be 190mA.

0 Shinichi Inoue over 9 years ago in reply to Ron Michallick

Guru 19671 points

Dear Ronald

Thank you for your e-mail.

I'll send this information to the customer.

I appreciate your great help.

Best regards,

Shinichi Inoue

0 Shinichi Inoue over 9 years ago in reply to Shinichi Inoue

Guru 19671 points

Dear Ronald

I was confirmed your suggested formula and curculated.

The result is not 190mA.

I am confusing, so could you please advise what is wrong.

Please see attached file.

Best regards

Shinichi

0312.question about TPL7407.ppt

0 Ron Michallick over 9 years ago in reply to Shinichi Inoue

TI__Guru*** 139956 points

Shinichi,

Each term is individually rooted like this. ( I fixed the formula error)

0.44 =SQRT(0.225) + 56% * (SQRT(0.165) - SQRT(0.225) )

0.44^2 = 190mA

0 Shinichi Inoue over 9 years ago in reply to Ron Michallick

Guru 19671 points

Dear Ron

Thank you for your reply and advise.

I could understand, the result is correspond to your suggestion.

So I'll send to the customer.

Best regards,

Shinichi

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TPL7407L the graph of D package Maximum Collector Current vs, Duty at 50deg