TPS2553 - Iin_off current

Eli az

Other Parts Discussed in Thread: TPS2553

Hello,

We are using the TPS2553 current limiter in our circuit.

During our tests we have discovered a strange behaviour.

While waking up the TPS2553 to Vin = 6.5V, with no load on output and EN is tied low, it seems that the input current rises up to ~20uA for the first about half a second and then falls to less then 1uA (As indicated in the data sheet) after about 4 sec...

This phenomenon gets worse as we lower the temperature, we've had pulses of over 1uA for as long as 2 seconds at around -30deg celsius.

Do you have any explanation for this behaviour?

Thanks,

Waiting for your reply,

Eli.

over 8 years ago

0 Eric Wright over 8 years ago

TI__Mastermind 42795 points

Hi,

Do you know if this can be repeated on the TI EVM? If so, I will set up the test and if we find the same behavior then I will check it with design.

Regards, Eric

0 Eli az over 8 years ago in reply to Eric Wright

Intellectual 720 points

Hi,

I am not using the TI EVM, but i am using the same peripheral components and connections as in the EVM, so im pretty sure that this behavior will be repeated on the EVM.

I will describe the phenomena again in more detail, the maximum current is about 20uA, and the duration is 45mSec in 25C. If you perform the test in -20C , the duration rises to 2 second.
I suggest you perform this test in -20C , it is easier to see this behavior.

Thank you,
Eli.

0 Milo Zhu over 8 years ago in reply to Eli az

TI__Intellectual 2795 points

Hi Eli,

Let me clarify your test bench: first EN pull low, then power on VIN = 6.5V, meanwhile measure TPS2553 INPUT supply current and found above behavior, right? I there any input cap in your test? Can you paste one VIN, EN power up waveform?

Best Regards

Milo