Inquiry about AQP package (QFN-8) among TS33 series products.

LSung.1 · ‎2024-02-01

Hello.

Three product packages are identified in the TS33's datasheet.

Among these, the QFN-8 package has 5 NC pins. Is it okay to connect them to VIN or VOUT or GND?

I couldn't find a additional explanation for the NC pin, so please check there is anything connected inside or it is a connection prohibition pin.

Thank you.

LSung.1 · ‎2024-02-11

All I wanted to know was whether connection to other pins was possible.

In the data sheets of many other products, there are cases where NC says 'no connect', but there are also cases where it says 'not connected'. So, like the product in question, it is difficult to understand the meaning of 'don't connect' without any explanation in the data sheet. For this reason, I think it would be good to have an explanation of NC in the data sheet.

From what I understand, in most cases
1. If it has a function like a test point but is not used externally and is not connected,
2. If there is an insulation problem with other circuits and performance is not guaranteed when connected,
3. This is the case for pins without internal connections in order to match the pin configuration of the package.

If there is no internal connection like number 3, the manufacturer may suggest attaching it to copper such as GND. Considering the other packages, I thought that case 1 would be rare, so I wanted to inquire to find out if it was case 2.

Apart from the above, there wasn't much room for wiring in the artwork, so I changed the package after thinking about it.

View solution in original post

tensaisakuragi06 · ‎2024-02-01

Some devices have a larger die size. Generally it is recommended to left these pins floating.

LSung.1 · ‎2024-02-08

Of course I think so, but because of the unnecessary NC pins, there are limitations to the artwork being done in a small area, so I wanted to check the manufacturer's answer.

Tesla DeLorean · ‎2024-02-08

Work with your FAE or local sales office / rep

The manufacture has TOLD you Not to Connect them, have the pads in the artwork, and don't connect them to anything, or each other.

@Billy OWEN

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LSung.1 · ‎2024-02-11

All I wanted to know was whether connection to other pins was possible.

In the data sheets of many other products, there are cases where NC says 'no connect', but there are also cases where it says 'not connected'. So, like the product in question, it is difficult to understand the meaning of 'don't connect' without any explanation in the data sheet. For this reason, I think it would be good to have an explanation of NC in the data sheet.

From what I understand, in most cases
1. If it has a function like a test point but is not used externally and is not connected,
2. If there is an insulation problem with other circuits and performance is not guaranteed when connected,
3. This is the case for pins without internal connections in order to match the pin configuration of the package.

If there is no internal connection like number 3, the manufacturer may suggest attaching it to copper such as GND. Considering the other packages, I thought that case 1 would be rare, so I wanted to inquire to find out if it was case 2.

Apart from the above, there wasn't much room for wiring in the artwork, so I changed the package after thinking about it.