TL331: TI TL331IDBVR material questions

Hi Wei,

you eventually violate the common mode input voltage range of comparator. So, what is the voltage at "SW_VR7" and what is the voltage at "VREF_VR7"?

I would remove the 100pF at the output of comparator. Such a cap causes high short circuit current spikes into the comparator output when the output toggles low. This will add unwanted ground noise and ground bounce internally of comparator which can destabilize the comparator, especially if no hysteresis is used as in your circuit.

And you should urgently add a gate resistor in the kOhm range. This not only to isolate the gate source capacitance from the output of comparator but also to protect the comparator if drain voltage spikes are injected into output of comparator via the drain gate capacitance. Sometimes even clampling diodes have to be added to protect the comparator output.

Kai

Kai

Thanks for the excellent support as usual.

Wei

In addition to Kai's comments, please include waveforms showing a part working properly and not properly so we can confirm all the voltage levels.  Would be best for you to include both inputs, output and VCC in the screen captures.  With this information, we can determine if VCM is being violated and if that is contributing to the difference between the different lot codes.

Thanks

Chuck

Hi Chuck and Kai,

Really appreciate your support and suggestion.

We tried to replace 100pF capacitor with 1Kohm resistor as your recommendation, the failure symptom we encountered was disappeared and passed in-circuit test, would you like to confirm what is the reason for this result?

For this PN, we purchased from TI from Y2018, and used up over 160K, our production and test processes have no change from Y2018. So we want to know what is the difference between DC2229(or DC2250) and DC2035? any EC or PCN implemented? What is the difference between device marking T1I8 and T1IG? What is the difference between MPN TL331IDBVR and TL331KDBVR?

Thank you.

Hi Ben,

Yes, the TL331 family is under PCN to change the die over to a new die so you may be getting a mix of the old and new die when ordering the TL331. This new die is the same die as the "TL331B" device. Top marking T1I8 is the new die and top marking T1IS is the old die. In general, the new "B" die is better for most specifications, this is summarized on the table on the front page of the datasheet. 

TL331K is the extended version temp range version up to 105C.

Hi Chi,

Noted with thanks.
Would you support to share the PCN about the die change with me? when was TI implemented this PCN? which material date code is the 1st of batch? For the top marking definition explanation, please also share the definition file. Besides the temperature range extended, any other difference between MPN TL331I and TL331K?

Hi TI team,

One more question, would you support to confirm what is the old or new die on MPN TL331KDBVR(DC2144, lot code 1099572HFT)? thanks.

Hello Wei,

See the following PCN:

Product Change Notification (PDF)

The existing devices will eventually be replaced with the "B" die, but under the same specs as the old die. At this time, you may be receiving a mix of old and new die. For new designs, we recommend using the TL331B.

The lot# you specified is the "old" die.

Hi Paul,

For TI PCN#20210318001.1, it released to Mouser from TI, please check and advise whether send the same PCN to IBM or Celestica in parallel? If so, please share the record. Of this PCN, I did not find die change item for TL331x series, the current and new die rev is A, not B, please support to double confirm, and please advise what is the detailed difference between die A and die B.

Please share TI device marking definition documentation, we want to know how to identify the marking, and please advise what is the difference between MPN TL331I and TL331K? whether TL331K can replace TL331L directly w/o more attention?

The proposed 1st ship date of this PCN is Jun.29 2021(the 27th week), why is the DC2144(end of Oct.) belong to "old" die?

The same PCN is sent to all (direct) customers. If you want to see IBM's or Celestica's records, you have to ask IBM or Celestia.

There is a new revision when a change is made to an existing die. But in this case, the old die is thrown away entirely, and the new fab uses a new die that was designed from scratch, so the new die revisions restart at A. (The "B" in the part number is not related to any die revision.)

The differences between TL331 and TL331B are shown in the datasheet.

The only difference between the I and K devices is the tested temperature range. Both I and K are being replaced with the TL331B, which has an even wider temperature range.

As long as both fabs are active, you might get old or new devices.