DA6512.003

2 December, 2016

24 (32)

TEMPERATURE MODE

The MAS6512 has an internal temperature sensor

for temperature measurement. The temperature

sensor

output

is

proportional

to

absolute

temperature (PTAT). The temperature information

is

needed

for

temperature

indication

and

temperature compensation.

The temperature measurement is started by writing

configuration data to the measurement control

register

In

the

temperature

measurement the internal regulator has to be

enabled

(TEMPREGEN=1)

and

the

internal

temperature sensor selected (SEL=10). The ratio

and difference converter bit (XRC) selection does

not have any influence on the result. Typically

already the smallest over sampling ratio (OSR)

selection 256 offers sufficient resolution for the

temperature measurement.

The internal temperature sensor has offset and gain

variation but small non-linearity (see Electrical

Characteristics table). Depending on temperature

measurement accuracy requirement the offset, the

gain and the non-linearity all can be compensated

by external calculations. In low precision the offset

and gain calibration is sufficient but in high precision

the second order non-linearity calibration can be

included.

Linear temperature sensor model

The linear temperature measurement model for output code is following.









REF

T

T

b

a

CODEFS

CODE











linearized temperature sensor model parameter values a and b are as follows.

a=0.38944

b=4.4329e-3

However it should be noted that the sensor has significant offset (parameter a) variation and also the gain

(parameter b) has some variation and that the above values represent only typical values. The non-linearity

temperature error after offset and gain calibration (best fit line) is typically <±0.5°C in the temperature range -

40°C…+85°C.











REF

REF

T

T

c

T

T

b

a

CODEFS

CODE

















model parameter values a, b and c are as follows.

a=0.38826

b=4.3967e-3

c=8.1098e-7

Above sensor model parameters are typical values which are subject to variations. The temperature error after