UCC21750QDWEVM-025: The chips are suspected to be fake，their silk-screen are different from others,please help to identify the fake stuff or real stuff ?

yantao zhao

Part Number: UCC21750QDWEVM-025
Other Parts Discussed in Thread: UCC21750

we have buyed TI IC UCC21750QDWRQ1 from mouser which are used on PCBA for our customer CRRC. Our end Customer test 6pcs PCBA，4 pcs among they are all faileded, and mark sure that there are some problems about IC UCC21750QDWRQ1 ,by the cross validation. Replacing the IC by samples from Ti ,PCBA can pass tests .
CRRC compare the samples from TI with the parts buyed from mouser ,finding that they have different silk-screens ,and that Ti marks are different.

firstly, please help us to identify the silk screen and Ti marks , it is fake stuff or real stuff ? why are the mark so different.

secondly, please heip us to make a FAE analysis to identify that the IC are fake or real parts.

thanks very much.

8 months ago

0 Sasikala Thangam 8 months ago

TI__Expert 6610 points

Hi Yantao Zhao,

Thanks for your interest with TI UCC21750 device.

Looks like both the TI markings are valid. You have mentioned that one of the units failed. Can you please elaborate what is the failure signature?

Thanks

Sasi

0 yantao zhao 8 months ago in reply to Sasikala Thangam

Prodigy 10 points

Hi Sasi：

there may be some problems about resistance between IN+ and IN- ,the 5V signal become 1V ,as folliowing picture.

we don‘t know the reason.what may cause the abnormal Phenomenon? The IC are fake ones?

0 Sasikala Thangam 8 months ago in reply to yantao zhao

TI__Expert 6610 points

Hi Yantao Zhao,

Thanks for the details -It is measuring 1V (when applied 5V) just after powering up? In the same setup, when replacing the ICs you are measuring 5V with TI ordered sample?

Is our understanding right?

+1 yantao zhao 8 months ago in reply to Sasikala Thangam

Prodigy 10 points

Yes ，your understanding is rigt.

0 yantao zhao 8 months ago in reply to yantao zhao

Prodigy 10 points

Yes ，your understanding is right.

0 Sasikala Thangam 8 months ago in reply to yantao zhao

TI__Expert 6610 points

Can you please measure what is the voltage just before the 100 ohm resistor (M1) and voltage close to controller side (M2)?

Is it possible to share a simple block diagram of what components between controller and the INP pin and the scope plot of the voltage measured for M1 and M2 during the issue.

Thanks

Sasi

Power management

Power management forum

UCC21750QDWEVM-025: The chips are suspected to be fake，their silk-screen are different from others,please help to identify the fake stuff or real stuff ?