SN74HC04: SN74HC04DR Abnormal problem

Part Number: SN74HC04

Abnormal problem
1. When using SN74HC04DR abnormal lot number LTC#: 15C9QPK, 15C9QKK, the RF Switch cannot be driven at the applied voltage of 4.95V (cannot be switched)
2. Replace the LTC# with the following lot number: OBATXSK/OBATXSK/9CA5HSK/9CA5HTK and all are PASS
3. It is also found that abnormal materials (LTC#: 15C9QPK, 15C9QKK) have a rising trend in resistance value with pressure drop

This material has been produced many times, why only these 2 batch numbers are abnormal?                                                                                                                                                                                                                               Please tell me how to find out the cause of the abnormality? We can provide test data, please provide FAE mailbox

  • Hello,

    I can help to try to troubleshoot the issue. The SN74HC04 had a change to the internals within the last year that may be affecting your application. Although the device still meets all datasheet specifications, some applications that utilize the device outside the datasheet specs can be affected.

    Can you share details regarding how the device is being used? A schematic and scope shots of the issue would be helpful.

    If you cannot share these publicly on this forum, I would recommend to start the FA process with your supplier so we can get those details through that process instead.

  • HI                                                                                                                                                                                                                                                                                                                                                         my  supplier  is TI STORE , so what can i do next ?     we can email   INVOICE/LABLE/BODY/TEST  DATA  .   Could  TI  FAE    HELP ? 

  • This forum is for technical support -- I can assist with changes to your design and analysis of the issue, however I have no control over orders and shipping or returns.

    There is a product return website located here to start this process: Product Returns 

    If you have trouble with the return process, please contact customer support here: Customer Support Center

  • The SN74HC04 had a change to the internals within the last year ??       what change  for sn74HC04DR  ? can offer  change  data or report?
    How to improve these abnormalities?

  • The SN74HC04 had a change to the internals within the last year ??       what change  for sn74HC04DR  ? can offer  change  data or report?

    The PCN was released June 30, 2020, here's a link to the copy available on Mouser.com: https://www.mouser.com/PCN/Texas_Instruments_PCN20200629000_20200630155743328.pdf

    An excerpt from the notification:

    Although the device was updated to a new process, as I said previously, the device continues to meet all datasheet specifications.

    How to improve these abnormalities?

    For (1) When using SN74HC04DR abnormal lot ... the RF Switch cannot be driven at the applied voltage of 4.95V (cannot be switched)

    We would need to see scope shots of the issue to determine what is going on. What voltage is output? What is the input voltage? What is the supply / ground voltage?

    For (2)  Replace the LTC# with the following lot number ... and all are PASS

    This is a great initial troubleshooting step to determine where the issue lies. Now that you know which IC is causing the issue, we need to get scope shots of a 'normal' operating device and a 'failing' device so that we can compare and determine where the issue lies.

    I assume you want to find a solution to this issue and not just return the units, so my goal is to find a lasting solution that will allow you to continue to use the HC04 or to find you a replacement that will operate correctly in the application.

    For a return, we need to identify that the device is not meeting the datasheet specifications somehow.

    For (3) It is also found that abnormal materials ... have a rising trend in resistance value with pressure drop.

    I'm not sure what you mean here - are you doing an atmospheric pressure test on the device? What is the measured resistance and how much does it change under how much pressure difference?

    We don't rate this type of device for pressure changes, so I'm not sure if this is something we will be able to help with, but it would be good to know if this is causing an issue for you.

    - - - - -

    I saw that you have submitted an FA request and included more information (schematics) in that request. I reviewed those and gave a response to the team handling your request. To determine if there is a failure, we need to see more details in regards to the operation of the device - most specifically, waveforms showing operation of the device normally, and when it is failing. Scope shots should include all inputs and outputs that may be causing an issue.

    Also, I noted that the schematic did not include a bypass capacitor - we recommend a 0.1uF capacitor placed close to the device.

    I can understand if you cannot share these details on this public forum. We can communicate through the FA process if necessary.

    If you do not wish to troubleshoot this issue with me on E2E, please mark this thread as "Resolved" so we can close out the thread. We can continue to discuss via email / through the FA process.

  • For (3) It is also found that abnormal materials ... have a rising trend in resistance value with pressure drop.

    I'm not sure what you mean here - are you doing an atmospheric pressure test on the device? What is the measured resistance and how much does it change under how much pressure difference?

    We don't rate this type of device for pressure changes, so I'm not sure if this is something we will be able to help with, but it would be good to know if this is causing an issue for you.

    Translation error
    The correct is : Voltage for these pins for ‘ good’ and ‘failing’ units were similar, but resistance of failing unit (LTC#:15C9QPK、15C9QK) goes up when we turn down supply  voltage.

    To determine if there is a failure, we need to see more details in regards to the operation of the device - most specifically, waveforms showing operation of the device normally, and when it is failing. Scope shots should include all inputs and outputs that may be causing an issue.

    Could you give me an example of what scope shots looks like, please? 

  • Could you give me an example of what scope shots looks like, please? 

    Any engineer that is capable of testing the device should know what an oscilloscope shot is.

    Please see thousands of images at this link: 

    *my apologies, the link broke. You can see thousands of examples by searching for "oscilloscope shots" on Google.com, select "Images" after searching.

  • Hey Sandy,

    I realize that you may have been asking for an example of what I want to see on the scope shot in this particular case, and my original response may not have been very helpful.

    This is a simulation of an input and output waveform from a typical inverter devices, which is approximately what I would expect to see in an oscilloscope shot of the input and output of the SN74HC04DR. We are looking for any issues in the operation of the device that are causing the described failure.

  • The oscilloscope graph is not helpful for the USER problem


    SN74HC04DR You said that this material may be caused by PCN changes
    Could you point that in datasheet ?
    What are the differences in the function caused ??
    please help to check if there is any difference for internal diode between new and old processes.

  • The oscilloscope graph is not helpful for the USER problem

    I see -- since timing is not an issue, which DC electrical specification is failing in the datasheet then? Output resistance is not a datasheet specification (although it is related to VOH and VOL).

    SN74HC04DR You said that this material may be caused by PCN changes
    Could you point that in datasheet ?

    As I have said previously, there are no changes to the specifications in the datasheet from the PCN update of the device. The new material meets all datasheets specifications.

    please help to check if there is any difference for internal diode between new and old processes.

    Which diode is of concern to the customer?

    The diode operating curve is not part of the datasheet specification. The process that the device is built on changed to a more modern design, so yes, the internal clamp diodes will have a different response than the old diodes. They are rated to meet the same current requirements and ESD protection that is in the datasheet.