SN74HCS74-Q1: SN74HC74QPWRQ1 vs SN74HCS74QPWRQ1

Youhei Miyaoka

Intellectual 1715 points

Part Number: SN74HCS74-Q1

Tool/software:

Hi team,

My customer plan to change to HCS74 from HC74. Could you answer below questions?

1. These are pin compatible, right? SN74HC74QPWRQ1 vs SN74HCS74QPWRQ1

2. HCS74 don't have input slew rate limit like HC74. Is this correct?

3. Is there anything else they need to be careful for replacing.

Regards,

Youhei MIYAOKA

22 days ago

+1 Clemens Ladisch 22 days ago

Guru 256060 points

Correct; as far as the guaranteed limits are concerned, the only difference are the Schmitt-trigger inputs.

However, the typical propagation delay of the HCS is lower. If your circuit does violate the setup/hold times, then it is possible that the HC accidentally worked where the HCS does not.

0 Youhei Miyaoka 3 days ago in reply to Clemens Ladisch

TI__Intellectual 1715 points

Hi Clemens,

Thank you for answering.

Regards,

Youhei

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SN74HCS74-Q1: SN74HC74QPWRQ1 vs SN74HCS74QPWRQ1