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AD7124 internal temperature sensor

Question asked by vangelov61 on Apr 27, 2017
Latest reply on Apr 28, 2017 by vangelov61


I'm trying to use the internal temperature sensor in AD7124-4. In the datasheet one can find only this description:


Embedded in the AD7124-4 is a temperature sensor that is useful to monitor the die temperature. This is selected using the
AINP[4:0] and AINM[4:0] bits in the channel register. The sensitivity is 13,584 codes/°C, approximately. The equation for
the temperature sensor is
Temperature (°C) = ((Conversion − 0x800000)/13,584) − 272.5


I tried to connect AINP to Temperature Sensor (16) and AINM to AVSS or DGND. So I get for the Channel_5 register 0xB211 (using Setup 3, because the others are used for other inputs). In Config_3 I have PGA=1 (but it doesn't matter), REF_SEL=Int_Ref, all Buf=Off. Burnout=off, Bipolar, so Config_3 = 0x810. When using the expression from the datasheet, I get (at room temperature) temperatures of 2-3 °C after power up and about 9°C after some minutes.


I hope somebody has already used the temperature sensor in the ADC and will post here the settings.

Sincerely yours,



The registers in AD7124-4 with values different from the reset values are:

Addr             Name    R-Data Init-Value Type

0x01       ADC_Control   0x0582    0x0000   R/W
0x07          Error_En   0x000040  0x000044 R/W
0x09         Channel_0   0x8020    0x8001   R/W
0x0a         Channel_1   0x8060    0x0001   R/W
0x0b         Channel_2   0x9051    0x0001   R/W
0x0c         Channel_3   0x9091    0x0001   R/W
0x0d         Channel_4   0xa0d1    0x0001   R/W
0x0e         Channel_5   0xb211    0x0001   R/W
0x19          Config_0   0x0871    0x0860   R/W
0x1a          Config_1   0x0051    0x0860   R/W
0x1b          Config_2   0x0050    0x0860   R/W
0x1c          Config_3   0x0810    0x0860   R/W
0x21          Filter_0   0xa60280  0x060180 R/W
0x22          Filter_1   0xa60280  0x060180 R/W
0x23          Filter_2   0xa60280  0x060180 R/W
0x24          Filter_3   0xa60280  0x060180 R/W