TPS25961: Precision of current limit

Darren Jenkins

Part Number: TPS25961
Other Parts Discussed in Thread: TPS2596, TPS1641

E-Fuse team,

Is there a value we can select for Rlim that would allow a customer to set the current limit to 2A, and ensure it is continue to conduct at 1.8A?

Based on customer testing, and the Overcurrent limit table in section 6.5, and the slope of the line in Figure 6-20, it looks difficult to have this kind of precision. What do you recommend?

Thanks,
Darren

over 1 year ago

0 Rakesh over 1 year ago

TI__Guru** 105191 points

Hi Darren,

TPS25961 has wider current limit accuracy. It is not possible to support 1.8A with 2A current limit setting.

Please look at TPS2596 https://www.ti.com/lit/ds/symlink/tps2596.pdf or TPS1641

BR,

Rakesh

0 Darren Jenkins over 1 year ago in reply to Rakesh

TI__Genius 11756 points

Hi Rakesh,

Thank you very much for looking into this.

Since this is a 2A current limit application, the TPS2596 looks like a better fit than TPS1641. The TPS1641 datasheet shows the highest example current limit as 1.881A.

A follow up question: in the datasheet for the TPS2596, it shows the Circuit Breaker current in the Electrical Characteristics section 7.5 is 1.5 A. Is this a mistake? Later in the datasheet, it shows the overcurrent protection is 1.5x ILIM. So I believe this spec should be adjustable based on the ILIM setting.

Thanks,
Darren

0 Rakesh over 1 year ago in reply to Darren Jenkins

TI__Guru** 105191 points

Hi Darren,

1.5A circuit breaker current is for a fault case when RILM = Short to GND (Single Point Failure Test IEC 62368-1) otherwise it is always 1.5* ILIM

Best Regards,

Rakesh

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TPS25961: Precision of current limit