MSPM0G3519-Q1: Dependency of ADC linearity on the temperature

Hi François,

The ADC linearity limits in Section 7.12.3 are specified over the full recommended supply-voltage and operating-temperature range. TI does not provide a separate guaranteed INL, offset, gain-error, or TUE limit for operation only up to 85°C. Therefore, the customer should use the published maximum values when performing a guaranteed worst-case analysis, even when their maximum junction temperature is 85°C.

For an external 3.3-V reference in 12-bit mode:

• INL: ±2 LSB
• Offset error: ±3.5 mV
• Gain error: ±4 LSB
• One LSB: 3.3 V/4096=0.806 mV

Using the datasheet equations, TUE ≈ 6.23LSB. This corresponds to approximately 5.0 mV, or 0.152% of the 3.3-V full-scale range. The datasheet explicitly states that the maximum linearity values apply over the recommended operating range, while typical values are measured at 25°C. Operating only to 85°C may produce better actual performance, but there is no published temperature coefficient or guaranteed derating method that can be used to calculate a tighter production limit. Linear interpolation between 25°C and 125°C would not be valid. For a design requiring tighter accuracy, the customer would need to perform system-level calibration or characterize representative devices across voltage, temperature, and manufacturing lots. Any resulting 85°C limit would be customer-derived rather than a TI-guaranteed specification.

-Brian