THVD2410: Components marked CHTP and AF75 have different parameters

Anna,

Can you elaborate on which parameters are different?

Regards,

Eric Hackett 

different is: rise/fall rate of the front. It affects on the operation of the device 

Differential output rise/fall time

Hi Anna,

Could you post a picture of each chips part marking - I need to trace both of them back into the system to ensure they are legitimate devices. 

Also since I am assuming you are talking about the rise/fall time on the "R" output pin could you tell me what is connected to that pin - like a capacitive load or what IC is attached to it. Reason I am asking is because the both of the parts you are showing are technically out of spec for this device - but we specify this with a 15pF load  - which if you go above that loading the output should slow. I imagine there is some type of additional capacitance as both devices are showing near max/ at max/ or above max for this - I assume this a room temperature measurement so that does seem a bit odd.  If you could share the entire schematic of the THVD2410 that would be helpful - but I understand that you may not be able to do that , but at the very least I do need to know what is loading the "R" pin as that can affect rise/fall time on that pin. 

Please let me know so I can dig deeper into the suspect parts  

Best,

Parker Dodson

Bellow you can find part of scheme. Please note that components with many other markings which were placed in the same place -performed well and parameter “Differential output rise/fall time” is in spec. So issue only with those 2 markings CHTP,AF75. 

Hi Anna,

1. I need the full part markings - not just the bottom 4 letters to trace them in our system - and I need to see how they are formatted as well - that is why I am asking for a picture of the top of each unit. I need this information

2. The differential rise time should not be that fast on teh THVD2410 - the differential rise/fall time is between 240ns and 600ns for the THVD2410  - the specs that are being measured seem to be much closer to the single ended transition time that is measured on the "R" pin. Where are they measuring rise time - also I need to know the loading on "R" because I don't think they are measuring differential - and if they are I really need to see the part markings because they are definitely not using the THVD2410 if those results are from the A/B pins. 

I need this information as listed above - if I don't get that then I can't help you - so please provide above information. 

Best,

Parker Dodson

We maked measurements in absolutely identical conditions, first with the chip with one marking (for example A6SS) and then with another marking (for example CHTP). The differential rise/fall time in the one marking corresponds to the specs, but with the second marking does not corresponds (the difference is about ten times) . During these checks, many chips were tested and everything was repeated. There is a clear difference in the chips by the differential rise/fall time for different markers. Why?

Anna,

Please refer to the my first point in the above reply - I need a full part marking - not just the 4 digits you have sent - I need all the text on the top of both units. It's not that I don't believe you that they are working differently - I need those markings to verify if the one of the parts you have is counterfeit. 

I need that information or I can't go farther on this request. 

Best,

Parker Dodson 

Here is the whole marking on the top of the component, we have sent it earlier, maybe you can send example of what you need?