• Resolved

TLV3702: Overall current consumption considering output volt level(zero load), un-used pins and aging.

Part Number: TLV3702

Hi, 

I have a few questions about the TLV3702.

1. Can the overall chip current draw exceed 2uA if used in this condition:

single supply 15V. 

channel 1 comparator: non-inverting pin connected to +15V rail, inverting pin connected to 8.8V ref. ouput pin drives a 10nF capacitor (2k ohm resistor in series) to high level and always holds there (no switching).

channel 2 comparator: not used. input pins connected to ground. output pin floating.

2. Datasheet says the max Icc per channel is 1uA. Can the Icc become larger after ten years of continuous operation? 

3.Does the input pins have internal hysteresis loop? Figures in section 8, page 13 of the datasheet show hysteresis loop sign. 

4. the typical Icc is 560nA at 25C". What is the possibility that I get this typical 560nA? 80%? any rough estimation is fine.  

Thanks.

Zhenyu

  • Hi Zhenyu,

    Here are the reply to your questions. Please let me know if have further questions.

    1. No. CMOS input, is not going to change supply current,
    2. TI DS specs are generally for 10 years
    3. No? I don’t think so.
    4. Typical = 1 sigma = 68%

    Best regards.

    Jian Zhang
    LPAC Apps engineer
  • Hello Zhenyu,

    As a follow-up, we received the following response from our Quality group:

    "Per TI Terms & Conditions, TI's warranty for devices is one-year after the sale of the part by TI to the customer or the sale of the part from the distributor to the customer. That being said, the FIT rate and MTBF for our parts does provide information on how long the parts are expected to last at certain operating conditions of the device in the customer application (see the Quality & Packaging section for the TLV3702).

    A calculation was done based on the data found on TI.com – the MTBF has been calculated at 2.75x109 cumulative device hours from a sample size of 30901 units. If we estimate the MTBF for a single unit, I come out with ~10.1 years for the TLV3702 at typical operating conditions (25C), TI has assessed that device silicon should last for ~10.1 years with a calculated FIT rate of 0.4 and an ELFR rate of 30 DPPM."

    To clarify, the 10 year specification is a design goal and is not warranted unless specifically stated on the datasheet or quality documents. Actual device life and drift is affected by many conditions and stresses beyond the control of TI.

    The MTBF and FIT estimator can be found here:

    http://www.ti.com/quality/docs/estimator.tsp

    The 1 sigma typical is a "rule of thumb" typical practice for the Amplifier groups, but is not always the case (depending on spec type and test conditions).

    Please see this Blog by our colleague Marek Lis on Long Term Stability:

     https://e2e.ti.com/blogs_/b/precisionhub/archive/2014/02/20/ic-long-term-stability-the-only-constant-is-change

     

    Regards,

    Paul Grohe

    Low Power Amplifiers and Comparators (LPAC) Applications

  • In reply to Paul Grohe:

    Hi Paul,

    Can you please show me how the  10.1 years is calculated? I want to convert the time to max ambient temperature of 90C. Your website gives me MTTF of  2.38e8 for 90C. It is much longer than 10 years. 

  • In reply to Zhenyu:

    Hello Zhenyu,

    Below is the response from the Quality Engineer. He was unaware of the 90°C application temperature.

    "With an application temperature of 90 °C and a qualification (HTOL) temperature of 125 °C, the MTTF (mean-time-to-failure) is calculated at 4.35*10^8 cumulative device hours (the customer is correct in using the derating tool to identify the ‘true’ theoretical MTTF). This is based on a sample size of 32095 devices; we can divide the total MTTF by the sample size which comes out to 13,553 device hours. Dividing by 24 hours/day and 365 days/year comes out to a silicon lifetime of 1.5 years (my original calculation showing 10.1 years assumed an application temperature of 25 °C as I was unaware of the real application temperature)."

     

    Regards,

    Paul Grohe

    Low Power Amplifiers and Comparators (LPAC) Applications

  • In reply to Paul Grohe:

    Hi Paul and Jian,

    Thank you for the explain and additional resources.

    Regards,

    Zhenyu