SN74LV00A: Part Number Date Code / Suffix Clarification

Mike N

Part Number: SN74LV00A
Other Parts Discussed in Thread: SN74AHC00

What's up TI.

This NAND gate is used to invert a 28 MHz bit clock driving the pixel grid on a 8" TFT LCD. We find that newer variants (2025) of this part have slightly more vertical edges than 2023 variants of the same part. Because of this the 2025 variant produces a high frequency harmonic at 489.7 MHz that causes us to fail EMC compliance. The 2023 version of this part does not produce this harmonic at all. I have attached macroscope photos of both. Can you please rationalize the differences between these parts?

LV00A 2023.jpg

LV00A 2025.jpg

4 months ago

0 Malcolm Lyn 4 months ago

TI__Mastermind 30990 points

Hi Mike,

If I had to guess, the newer batch of this device was update from 200mm wafer to 300mm. This means the size of the die inside the package is smaller. The ratio of bond wire length to die size is different and is probably affecting the frequency response of the circuit.

Best,

Malcolm

0 Mike N 4 months ago

Prodigy 100 points

What's up Malcolm Lyn. Thanks for the response. Any chance we can still buy the older part, i.e. with the 24KG4 / CPEO markings?

0 Clemens Ladisch 4 months ago in reply to Mike N

Guru 320660 points

It's unlikely that you will be able to find an old device anywhere.

The SN74AHC00 is essentially the same device with half the output drive strength.

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SN74LV00A: Part Number Date Code / Suffix Clarification