Discussion in 'General Electronics Chat' started by robby991, Jan 16, 2008.

  1. robby991

    Thread Starter Active Member

    Dec 17, 2007
    Hello. I have a question as to what characterization means. If someone has a chip that they need to characterize, what exactly does this mean? How would one go about doing this? Thank you.
  2. Dave

    Retired Moderator

    Nov 17, 2003
    It would be beneficial to see it stated in context, but generally when discussing characterization we refer to definite/deducing/deriving the parameters that characterize a particular aspect of a chip or process.

    As for how one would do this, well that would depend on what you want to know about the chip or process.

  3. thingmaker3

    Retired Moderator

    May 16, 2005
    Among other definitions of "characterization" is the precise shaping & physical adjustment of induction heater work coils for optimal heat pattern in specific parts. This can be done by trial and error, or with a frightening amount of calculus.
  4. Distort10n

    Active Member

    Dec 25, 2006
    Hello Robby this is something that I often do while helping the test engineers.

    'Characterization' is a (usually) thorough testing process. A device's parameters are tested agianst certain conditions in order to ensure that the stated datasheet electrical parameters can be met. It is a sanity check to make sure what was designed and simulated will be replicated in actual silicon. This is to make sure there that the silicon process is correct, assembly and packaging do not affect designed parameters, or many other issues that could rear their ugly head.

    For instance, an IC designer designs an op-amp with certain parameters (Vos, Icc, bandwidth, etc.). When silicon arrives in house we want to make sure that the Vos is within process corners. Perhaps the datasheet states a Min/Max Vos rating of 1mV/5mV.

    I would test that parameter against a certain common-mode voltage, supply voltage, load, against temperature or quite literally, whatever the conditions that were determined for functionality of the device for a parameter.

    Characterization can happen with one wafer lot, or several wafer lots to ensure that process corners are not 'violated.' In other words the designer expects a gaussian distribution for parameters. If I test a parameter, again Vos, and I measure 10mV when the MAX is expected to be 5mV then we must determine what is happening. Is it a process issue? Assembly issue? Packaging issue? Test setup issue?

    This is a very deep subject so feel free to ask more questions.

    In summary, characterization is an involved testing process to ensure the behavior of a device's parameters (usually with given conditions) are within expected limits of the design.

    Do you have a datasheet or a part number? This sounds like a device where the behavior of a devices pins (input/output voltages/currents) need to be tested given certain conditions.
  5. Dave

    Retired Moderator

    Nov 17, 2003
    Can I also suggest you have a look ate Chapter 4 in CMOS VLSI Design by Weste and Harris - Circuit Characterization and Performance Estimation. This chapter covers all aspects of characterisation of circuit designs in detail.