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OPA1S2384 / OPA1S2385 Data sheet lacking

Chris Roden
Prodigy 110 points
Other Parts Discussed in Thread: OPA1S2385, OPA1S2385EVM, TS5A4595, TS5A4594, OPA1S2384, OPA2354, OPA2345

I have two questions about the OPA1S2385 which did not appear to be answered in the data sheet.


1) what are the electrical characteristics of the buffer section (op amp B) or does it have the same characteristics of op amp A (high bandwidth, FET input)?

2) What is the Quiescent Current of the entire OPA1S2385 device? The data sheet lists Quiescent Current: 9.2 mA (per amplifier). Does this mean that the entire device has a Quiescent Current of 18.4 mA, or does this current of 9.2 mA refer to the entire device with the buffer not counting as an amplifier?]

  • 0
    TI__Genius 13935 points

    Hello Chris,

    I have not worked with this chip, but it appears that aside from on chip parasitics associated with the switch channel A and channel B should be identical.  The circuits shown in the application section indicate the both stages should have similar performance.  

    The total current would be 18.4mA.   

    Loren

  • 0 in reply to Loren Siebert 1
    Prodigy 110 points

    Hello Loren,

    I have the OPA1S2385EVM, and with nothing other than power connected, I measure 8.24mA total.  The chip only comes in a configuration with two op amps and the bullet on the first page states " Quiescent Current: 9.2 mA " .  This all leads me to believe that the total quiescent current for this chip is around 9mA (for both op amps).

    Is the "(per amplifier)"  just a hold over from other data sheets with single, dual and quad options?

    If this is true, then I am still curious if the op amp B has the same properties as op amp A.  I do not statement to this possibility.

    I do not see any suggestions that someone may what to use the two op amps separately (as independent high bandwidth, FET-input op amps)

    Thanks

    Chris R.

  • 0 in reply to Chris Roden
    TI__Genius 13935 points

    Hi Chris,

    I will have to look into this more.  I just am not that familiar with this part.  

    Loren

  • 0 in reply to Loren Siebert 1
    TI__Mastermind 27715 points

    Hello Chris,

    1. The OPA1S2384/OPA1S2385 is a multi-chip module consisting of an OPA2354 and a TS5A4594/TS5A4595 signal switch. Treat the two amplifiers inside the OPA1S2384/OPA1S2385 like you would two amplifiers inside a dual package - their specs will meet the conditions in the electrical table but their individual characteristics may vary slightly, especially over temp.

    2. The quiescent current spec of 9.2 mA (typical) is correct for the entire device. The "per amplifier" bit is an overlooked relic from the OPA2354 data sheet, where each amplifier has a typical IQ of 4.9 mA. I actually wasn't aware of that typo - thank you for bringing it to my attention.

    Let me know if you have any other questions regarding this device.

    Best regards,

    Ian Williams
    Linear Applications Engineer - Op Amps
    Precision Analog 

  • 0 in reply to Ian Williams
    Prodigy 110 points

    Hello Ian,

    Thanks for your response.  That clears up all of my questions.  I think the information regarding the individual components of the MCM (OPA2345 & TS5A4594) would be very helpful additions to the data sheet.

    Thanks,
    Chris R.