SN74AHC594: The 2025 version of SN74AHC594 fails to operate.

switch

Part Number: SN74AHC594

Hi ti team,

The customer’s system works normally with the 2022 version of SN74AHC594, but fails to drive LEDs when replaced with the 2025 version of SN74AHC594. Could you please confirm if there are any changes made to the 2025 version of SN74AHC594? Thanks!

26 days ago

0 Albert Xu1 26 days ago

TI__Mastermind 41965 points

Hi,

There has been a PCN for this device where it has moved to a new process on 300mm die.

Can you please share some more information on your usecase and how the device is failing?

0 switch 24 days ago in reply to Albert Xu1

Genius 3900 points

Hi Albert，

With the same control program, the 2022-version IC can light up the LED normally, while the 2025-version IC fails to do so. Please find the schematic diagram attached for your reference!

keyboard.pdf

0 Albert Xu1 24 days ago in reply to switch

TI__Mastermind 41965 points

Hi,

Do you have some scope shots of expected vs unexpected behavior as a comparison?

The schematic looks to be OK, so the next step is to look into how the signals are behaving.

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SN74AHC594: The 2025 version of SN74AHC594 fails to operate.