CD74HC14: CD74HC14E marking explanation

abdelmajid moudakir

Part Number: CD74HC14

Tool/software:

Hello,

I am doing some investigation regarding CD74HC14E thru hole hole part . would you please you please provide me documentation to understand the the marking on this chip . The marking on this chip is 3CA4QNMG4

thank you

6 months ago

0 Albert Xu1 6 months ago

TI__Mastermind 38535 points

Hi,

We do not provide "translation" instructions for preventing counterfeits.

0 abdelmajid moudakir 6 months ago in reply to Albert Xu1

Prodigy 55 points

would you please help me identify that the part I have is not counterfeit thank you

0 abdelmajid moudakir 6 months ago in reply to abdelmajid moudakir

Prodigy 55 points

Hello

i got several CD74HC14E with different marking

32ACG7KE4 32ACFZKE4 2BA5ZGKE4 Pass test

3CA4QTMG4 3CA4QNMG4 3CA4QNMG4 Fail test

i used these chips in the same PCB with a socket. Based on the test results looks like any 3XXXXXMG4 is not passing the test . Please help me findout what is happening so we can buy the right chip

Thank you

0 Albert Xu1 6 months ago in reply to abdelmajid moudakir

TI__Mastermind 38535 points

Hi,

Can you please elaborate what the problem you are seeing is?

0 abdelmajid moudakir 6 months ago in reply to Albert Xu1

Prodigy 55 points

Hello

We made and square signal generator using MC74HC14AN. MC74HC14AN is obsolete and we got CD74HC14E as a substitute.

CD74HC14E (32ACG7KE4 32ACFZKE4 2BA5ZGKE4) works but is does not generate same frequency as CD74HC14E (3CA4QTMG4 3CA4QNMG4 3CA4QNMG4).

Would like to know why same chip different marking is not getting me same result.

Do you believe MC part is same as CD part?

thank you

0 Clemens Ladisch 6 months ago in reply to abdelmajid moudakir

Guru 317370 points

It is likely that your circuit relies on characteristics that are not guaranteed by the datasheet. Please show the schematic.

0 abdelmajid moudakir 6 months ago in reply to Clemens Ladisch

Prodigy 55 points

I'm unable to show you schematic cause of company policy.

0 Clemens Ladisch 6 months ago in reply to abdelmajid moudakir

Guru 317370 points

I'm unable to help you because of your company policy. Try adjusting the R/C values.

0 abdelmajid moudakir 6 months ago in reply to Clemens Ladisch

Prodigy 55 points

Would you please tell me why some chips works and some did not. its same part number with different marking. Our boards are certified and cannot change a single component. the board was made in 1980's never failed . please help me understand

0 Clemens Ladisch 6 months ago in reply to abdelmajid moudakir

Guru 317370 points

The newer CD74HC14 chips use a different die. The guaranteed datasheet parameters (e.g., V_IL, V_IH) have not changed, but typical characteristics (e.g., the actual switching thresholds, which are somewhere between V_IL and V_IH) are different. The actual voltage at which the inverter switches affects the oscillator frequency.

Logic devices do not have precise switching thresholds. If accurate frequency is important, the circuit must be designed with a comparator instead.

0 abdelmajid moudakir 6 months ago in reply to Clemens Ladisch

Prodigy 55 points

Dear Clemens,

Thank you for the explanation.

0 abdelmajid moudakir 6 months ago

Prodigy 55 points

Hello sir

Would you please provide me the new datasheet for CD74HC14E. I need to know what exactly got changed from MC74HC14 . Maybe i ll be able to modify something

thank you

0 Clemens Ladisch 6 months ago in reply to abdelmajid moudakir

Guru 317370 points

The min/max values have not changed. The typical values are different, and they can change with different fab sites or die revisions. You have to design your circuit so that it works with such variations. In the case of an R/C oscillator, you have to adjust the R/C values.

0 abdelmajid moudakir 6 months ago

Prodigy 55 points

hello Sir ,

I got it to work by reducing VCC from 5v to 3V . do you have an explanation? datasheet says VCC is from 2V to 7V .

thank you

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CD74HC14: CD74HC14E marking explanation