TPS1641: Efuse Ilim accuracy

Luca L

Part Number: TPS1641

Tool/software:

Hello Everyone,

I'M working on an electronic boards that require the usage of eFuses. For this purpose I decided to use TPS16413DRCR (latched version) eFuse.

The device seems to work fine except for the fact that the current threshold seems to be higher than the one resulting from the application of the formula reported in the datasheet.

Here are the values:

CdvdT= 100nF;

Cidly= 22nF;

Riocp=8.2k

Rlim=6.8k

With these values and according to the formulas I should have a Ilim=1.45A and Iocp=2.01 A. The issue is that when I test the circuit with the active load increasing slowly the current, the eFuse trips at 1.72A

It seems that the real Ilim is something like 20% higher than the theoretical value from the formula. Can someone help me regarding this issues?

9 months ago

0 Amrit Jit 9 months ago

TI__Mastermind 30681 points

Hello Luca,

Which load are you using?

Is it restive load or e-load?

Thanks

Amrit

0 Luca L 9 months ago in reply to Amrit Jit

Prodigy 10 points

Hello Amrit,

I'm using an eLoad. I already seen this answer also on other threads, but I don't understand why eload is problematic

0 Amrit Jit 9 months ago in reply to Luca L

TI__Mastermind 30681 points

Hello Luca,

e-load usually operates as a constant current source or sink to take current with fixed programmable value.

e-Fuse in current limit also acts a current source. so, it's like connecting two current sources in series with different values.

It's better to check on resistive load for evaluation.

Thanks

Amrit

+1 Luca L 9 months ago in reply to Amrit Jit

Prodigy 10 points

Hello Amrit,

I tried also with resistive load but the behaviour of the eFuse is still the same. I think that for now the best solution is to increase the value of the resistor of 20% to compensate for the error.

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TPS1641: Efuse Ilim accuracy