Ambient temperature of AD8495

Hello All,

I have a question about ambient tempareture of AD8495. According to the datasheet of AD8495, the ambient tenperature rang is 0 deg C to 50 deg C. If we use AD8495 under -40 deg C to 55 deg C, how temp. accuracy can we get?

Best regards,

Akira

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  • +1
    •  Analog Employees 
    on Jan 16, 2019 7:52 AM

    Hi Akira,

    I need to check if we have data or calculation how much Ambient Temperature Rejection spec will change once you operate outside the specified ambient temperature range.  Just an additional info from the older thread:  "The AD849x thermocouple amplifiers are operational from -40°C to 125°C, and the internal temperature sensor is operational over this entire range. However, all thermocouples naturally have an output voltage which is non-linear. Therefore, in order to compensate the non-linear error with the linear temperature sensor, the accuracy was optimized for a reduced reference junction temperature range, which is 0 to 50°C for AD8495 and 25 to 100°C for AD8497. Across this range, the extent to which the compensation from the temperature sensor does not match the thermocouple signal is captured by the Ambient Temperature Rejection specification. Any initial error in the temp sensor output that produces an offset is included in the Initial Accuracy specification.

    Some more information that might help is provided in AN-1087."

    Best regards,

    Emman

Reply
  • +1
    •  Analog Employees 
    on Jan 16, 2019 7:52 AM

    Hi Akira,

    I need to check if we have data or calculation how much Ambient Temperature Rejection spec will change once you operate outside the specified ambient temperature range.  Just an additional info from the older thread:  "The AD849x thermocouple amplifiers are operational from -40°C to 125°C, and the internal temperature sensor is operational over this entire range. However, all thermocouples naturally have an output voltage which is non-linear. Therefore, in order to compensate the non-linear error with the linear temperature sensor, the accuracy was optimized for a reduced reference junction temperature range, which is 0 to 50°C for AD8495 and 25 to 100°C for AD8497. Across this range, the extent to which the compensation from the temperature sensor does not match the thermocouple signal is captured by the Ambient Temperature Rejection specification. Any initial error in the temp sensor output that produces an offset is included in the Initial Accuracy specification.

    Some more information that might help is provided in AN-1087."

    Best regards,

    Emman

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