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Original question:

TPS544C25: Diff Amp Error Voltage

TPS544C25: Remote sense amplifier temperature coefficient

Christopher Arntzen
Intellectual 630 points
Part Number: TPS544C25

In a previous post, I asked about the temperature coefficient on the TPS544C25 voltage regulation.

The response was: "While a typical part has a flat temperature response, any given part could have a small positive or negative temperature coefficient resulting in a 0.5% tolerance over the full temperature range."

My follow-up questions:

  1. does the output voltage increase or decrease with increasing temperature?
  2. is the +-15mV offset voltage (VDIFFO(err) w/ Vout=3V) temperature dependent, or a fixed offset?
  3. does the temperature dependence result in a linear drift in voltage regulation, a logarithmic drift, or some other function drift?
  • 0
    TI__Guru 56985 points

     

    I will pull the specific data but:

    1) The output voltage variation is primarily determined by a curvature corrected bandgap reference which is generally highest between 0 and 40C and falling at both hot and cold temperatures, but there is some part to part variation in the exact curve of this bandgap.  Some devices will show a positive TC, some devices will show a negative TC while most devices will show the concave down curve that is lowest at both hot and cold.

    2) The +/- 15mV offset voltage is primarily a non-temperature dependent +/- 0.5% gain error.  I will check how much of the +/- 15mV error comes from voltage-drift.

    3) I will need to check on this as well.

  • 0
    TI__Guru 56985 points

     

    I pulled out Temperature characterization data on the remote sense amplifier.  The mean drift of the error over temperature from -40°C to +125°C was about 0.1mV and not statistically significant with a 1mV standard deviation in the measurements, but does show a generally positive trend.

    The characterization was done a while ago and individual devices were not serialized for individual drift tracking, but the standard deviation is steady from 25°C to 125°C, but and only very slightly higher at -40°C suggesting very little offset or gain drift over temperature.