TPS2551: Rlim value

Pon Paulraj

Part Number: TPS2551
Other Parts Discussed in Thread: TPS2553D

Hello,

I am planning to use TPS2551QDBVRQ1 in an application where I have to limit the USB current (Ioc) to 150mA. (USB/voltage should disable if someone draws more than 150mA). For achieving Ioc = 150mA, I need about 158K Ohms limiting resistor. But the datasheet recommends not to use more than 80Kohm. In that case, is it adviseable to use this chip for this application (with 160K)? What will be the imapct? Will I losse accuracy or life time or why it was recommended not to go above 80K . Please advise.

Thanks

over 7 years ago

0 Aramis P. Alvarez over 7 years ago

TI__Genius 10370 points

Hi Pon,

Welcome to E2E! Our engineering experts should get back to you on Monday, Oct. 9th. They're currently on a holiday.

0 Michael Tan over 7 years ago

TI__Expert 8420 points

Hi ,

If you use 158K , the accuracy will out of datasheet gurantee. This device original design Rlimit is not exceed 80K.

0 Pon Paulraj over 7 years ago in reply to Michael Tan

Prodigy 60 points

Hello Michael, Thanks for the reply. Can you please give more details. 1) What will be the loss of accuracy when I use it with 158K ? Will it be 10-20% (which is acceptable for my usecase) or will it be more than 20%? 2) The Chip is specéd for as low as 100mA, how this 100mA be possible if you can not go above 80K? 3) Is there any option to achieve Ioc of 150mA within the spec's of the chip. 4) Considering Will you advise us to use this chip for our application (150mA) or it's recommended to look for other options. Please let us know asep. Thanks,

0 Michael Tan over 7 years ago in reply to Pon Paulraj

TI__Expert 8420 points

Hi Paulraj,

You can try to choose TPS2553D for your application.

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TPS2551: Rlim value