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CD74HC244: CD74HC244M96 ESD Conformance

Richard Long
Prodigy 50 points
Part Number: CD74HC244
Other Parts Discussed in Thread: SN74HC244, , CD54HC244

Hi,

We are currently using a CD74HC244M96 part (SCHS167E– November 1997 - Revised October 2004) which is required to meet the Human-Body Model test, JEDEC JS-001. I cannot find anything on the datasheet that confirms that this part conforms to this test. However, I have noticed the similar commercial part SN74HC244 (SCLS130E –DECEMBER 1982–REVISED MAY 2016) does conform to this rating at 2kV.

Is it possible to tell me if the CD74HC244 part also conforms to this standard, or what the ESD levels are. Failing this, is there any data avaliable for the protection diodes on the input and output pins to the Vcc and GND rails that are limited to 20mA.

Many Thanks,

Richard

Richard Long

Electronics Engineer – Control Systems

Civil Aerospace

Rolls-Royce

The Derwent Building

5000 Solihull Parkway

Birmingham Business Park

Solihull

B37 7YP


 

  • 0
    TI__Guru* 96641 points
    Hi Richard,
    CD74HC244 is not rated for ESD, and thus is not guaranteed to meet the HBM standard listed. I can check tomorrow when I return to work if there was an ESD evaluation done on this device when it was acquired from Harris Semiconductor.
  • 0 in reply to Emrys Maier
    Prodigy 50 points

    Hi Emrys,

    Thanks for your reply, hopefully some ESD evaluation may have been completed. If that is not the case we do have some external ESD transient protection diodes for this device. However, to ensure there is enough overhead these are not activated until over the 3.6V rail (6.1V they start to conduct). So the 2.5V difference we do not want to overstress the internal IC diodes on the CD74HC244. I understand from the datasheet that these can handle a constant current of 20mA. As our ESD test is a maximum duration of 10ns, is there any pulse data that these diodes could conform to?

    Thanks

    Richard

  • 0 in reply to Richard Long
    TI__Guru* 96641 points
    Hey Richard,
    After digging a bit I found a qual report showing a 4kV HBM passing result for this device.

    Is there a reason you aren't using the SN74HC244? I saw that you mentioned that the SN74HC244 is a commercial rated product before - but so is the CD74HC244. Perhaps you're looking for the mil-spec device, CD54HC244? If that's the case, we're talking about very significantly different parts.
  • 0 in reply to Emrys Maier
    Prodigy 50 points

    Hi Emrys,

    Thats great detective work there to dig out the report. Is it possible that a copy could be provided? or details of the test, such as standard used, pulse width, peak amplitude etc.?

    On the device front  I thought I would clarify up some information from my end. We are using the CD74HC244 as from the datasheet even though it is commercial it meets the military temperature range of -55 to +125 that we require in a surface mount package. We did look into the SN74HC244 but as you state this is only -40 to +80 which is unsuitable for our needs. Finally the CD54HC244 on offer is a great part that exceeds our requirements and also is not abaliable in a package that is surface mount and matched to our PCB's for thermal expansion.

    Many Thanks,

    Richard

  • 0 in reply to Richard Long
    TI__Guru* 96641 points
    Hey Richard,
    I can get you in touch with our military/high reliability team to see if they can get that package approved for the CD54HC244 device you need.

    I can't post this report publicly as it contains some confidential information. Can you email me directly so we can discuss? My email is Emrys (at) ti.com. If you have a local TI representative, it would be even better to go through them as they likely know all the details of your account with us.