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OPA2132: New Date Code Part Failure, Date Code: 3725 & 4025

Joseph Teoh
Prodigy 10 points

Part Number: OPA2132

Hi Texas Instruments Support Team,

I would like to request your assistance in reviewing an electrical behavior difference observed on one of your devices used in our production testing.

 

Part Information

  • Manufacturer: Texas Instruments
  • MPN: OPA2132UA/2K5
  • Affected Date Codes: 3725, 4025
  • Reference (Known Good) Date Codes: Older date codes of the same MPN

Issue Summary
During final verification testing on our product, we observed consistent failures at the AO_Solution_Voltage test step when using devices from the newer date codes listed above.

In our application, the OPA2132 is used in an analog signal conditioning circuit, where we measure AO_Solution_Voltage, which represents the dark voltage / zero‑input output offset of the analog chain. This measurement is performed under a no‑input (dark) condition after the circuit is allowed to settle.

With the existing test condition (measurement taken after a 210‑second delay), the AO_Solution_Voltage from the newer date code material drifts into the negative range (approximately –100 mV to –800 mV), resulting in test failures. Under the same conditions, older date code material remains stable within specification (0–200 mV) and passes consistently.

Additional Observations

  • Reducing the measurement delay to 30–45 seconds results in stable readings of approximately 10–20 mV for the newer date codes, well within specification.
  • No other electrical or functional parameters are impacted; all other tests pass consistently.
  • This behavior suggests a faster discharge characteristic in the newer date code material compared to previous production lots.

 

Request for TI Feedback

  • Is there have been any ECNs, PCNs, or manufacturing/process changes (e.g. silicon revision, fab location, assembly, test flow, or materials) for OPA2132UA/2K5 over the past few years, particularly around the affected date codes.
  • Any documentation or summary TI can share regarding change history relevant to this part number.

 

  • 0
    TI__Expert 6630 points

    Hi Joseph,

    The differences you are seeing in the OPA2132 can be attributed to the PCN found HERE. This PCN change is part of TI’s multiyear plan to transition products from our 150-millimeter factories to newer, more efficient manufacturing processes and technologies, underscoring our commitment to product longevity and supply continuity.

    The updated device was designed to closely match the behavior of the original device and the datasheet was updated to reflect any changes. You can find the this list of updates in Section 9 of the OPAx132 datasheet.

    However, there are some slight differences that could be the root cause of the failure you are seeing. Can you provide the application circuit for analysis?

    Best regards,
    Carrie

  • 0
    Prodigy 10 points

    Hi carrie, 

    Due to confidentiality restrictions, we are unable to attach the full schematic. However, the OPA2132 application is functionally equivalent to the following description.

    The circuit uses two cascaded OPA2132 stages powered from ±15 V:

    • The first OPA2132 stage is configured as a buffer / amplifier receiving the detector signal through resistors and RC filtering networks (AC‑coupling and noise filtering). The detector presents a relatively high capacitive load to the amplifier input.
    • The second OPA2132 stage is configured as a non‑inverting amplifier with resistive feedback. Its output is routed to AO_SOLUTION_VOLTAGE, which is measured by downstream ADC / test circuitry.

    During this specific test condition, the input signal is at zero (dark / no‑input condition), and AO_SOLUTION_VOLTAGE is measured after approximately 210 s settling time, with no active switching during the delay period.

    We discussed this internally, and one hypothesis raised is the possibility of slight differences in dynamic behavior (e.g. loop response / effective GBW or capacitive‑load sensitivity) in the newer date‑code devices, which may interact with the detector’s capacitive load and long settling condition.

    We understand from the PCN that the device was redesigned to closely match prior behavior. Could you please advise whether:

    • Any changes affecting stability margin, compensation, or capacitive‑load driving behavior could explain this long‑term drift, and
    • Whether additional output loading, bias return, or stability recommendations would be appropriate for this application?


  • 0 in reply to Joseph Teoh
    TI__Expert 6630 points

    Hi Joseph,

    One AC spec that is different in old vs. new design is the gain bandwidth. The typical value is now higher, closer to 11 MHz. This could have an effect on the stability of your circuit considering you have a high capacitive load on one of your outputs. I understand why you cannot share your schematic directly, but we can move this offline if you are able to share more information directly there.

    To determine if you are experiencing stability issues, we would need to run a stability analysis on your circuit. If you'd like to do this internally, the technical paper Op Amp Stability Theory and Compensation Methods offers great step by step instructions on this method.

    Let me know what you think.

    Best regards,
    Carrie