• State TI Thinks Resolved
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 36 views
  • Users 0 members are here
Support feedback
Options
Options
Related

Original question:

RC4580: Required RC4580IDR AMRT&CMRT&EMRT report

RC4580: abnormal current for different size chips

Chi Zhang2
Intellectual 2700 points
Part Number: RC4580

Tool/software:

Hi Expert, 

we find one issue about current in customer side, there is 17mA output current in failed chips, while normal device is 7-8mA current. 

also we check the X-Ray, finding device include small and big die? Why and what is the difference? 

support need:

  • what is the difference between small size die and big one? we have 30% failure in small one
  • we use multimeter to test chip impedance(remove from board) of Vcc+ pin 8 and Vcc- pin 4, find both good and bad Vcc+ to Vcc- is 617-668 ohm,  Vcc- to Vcc+ is 1380-1900 ohm in good chip; Vcc- to Vcc+ is M ohm in bad chip. what is the normal impedance range for Vcc+ and Vcc-

RC4850 device under X-Ray:

DC code and lot number: (top is bad one, bottom is good one)

BR

Chi

  • 0
    TI__Mastermind 25260 points

    Hi Chi, 

    This is most likely related to the product change notification that was sent out on November 15, 2023. 

    Product Change Notification

    The RC4580 was redesigned and also changed fabs to RFAB, detailed below. We have been seeing a trend at contract manufactures that do in circuit tests or ICT tests where pins are measured for resistance and when they see a difference it is noted as a failure. More often than not this is just an observation that something has changed between the old device and the new device, however it isn't necessarily causing an application circuit problem. The new device was designed such that it will meet or exceed the old device specs. In the rare instance that something was worse we would update any spec to the worst spec. 

    Can you confirm if there is an application functionality failure or is this an observational difference only?

    Best Regards, 
    Chris Featherstone

  • 0 in reply to Chris Featherstone
    TI__Intellectual 2700 points

    Hi Chris, 

    for other function, we didn't do test to verify. 

    background is customer use current as device good sign, if it is over normal range, all the other circuit will be reset. in our datasheet, the current max is < 8mA. so customer use 7-8mA as standard, although our datasheet max is +-50mA.

    as you mentioned, there are some specs of new device worse than old one. could you help to clarify the current distribution for the new fab. because we find 70% are in <8mA range, so in my perspective, the new device should has more discrete current distribution. if there are any other spec which has been affected, please also help to figure out. there is 1Mu pending inventory in customer factory. 

    My support need:

    • new small one is new LBC9 fab, and old one is Mex. please help to share the current distribution for new device. 
    • very appreciated if if you could share other worse spec than datasheet
    • when will we update these spec in the datasheet.

    BR

    Chi

  • 0 in reply to Chi Zhang2
    TI__Mastermind 25260 points

    Hi Chi, 

    We can further discuss over email. To be clear I am not saying that any spec is worse. We transitioned many devices to new fabs and in the rare instance that a spec became worse for any device transitioned it should have already been updated in the product datasheet. If the spec meets the current spec or is better it is not updated because the old and new devices exist on the market as of now. There should be no impression that a bunch of specifications are now worse than the old device. We can discuss further over email. 

    Best Regards, 
    Chris Featherstone