MC9S08SH8CTJ Datasheet, PDF (127/341 Pages) Freescale Semiconductor, Inc – MC9S08SH8 Datasheet

Chapter 9 Analog-to-Digital Converter (S08ADCV1)
In application code, the user reads the temperature sensor channel, calculates V_TEMP, and compares it to
V_TEMP25. If V_TEMP is greater than V_TEMP25 the cold slope value is applied in Equation 9-1. If V_TEMP is
less than V_TEMP25 the hot slope value is applied in Equation 9-1.
Calibrating at 25°C will improve accuracy to ± 4.5°C.
Calibration at three points, -40°C, 25°C, and 125°C will improve accuracy to ± 2.5°C. Once calibration
has been completed, the user will need to calculate the slope for both hot and cold. In application code, the
user would then calculate the temperature using Equation 9-1 as detailed above and then determine if the
temperature is above or below 25°C. Once determined if the temperature is above or below 25°C, the user
can recalculate the temperature using the hot or cold slope value obtained during calibration.
Figure 9-1 shows the MC9S08SH8 with the ADC module highlighted.
MC9S08SH8 MCU Series Data Sheet, Rev. 3
Freescale Semiconductor
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