Because the Test Board need to work at high temperature,so I want to know the condition of ADuCM360 work at 120℃.

Test Board:Minimum system of ADuCM360,Temperature measurement circuit and the code are according to the development kits of official website.Other circuits includes RS485 and so on.

All devices‘ operating temperature range are -40℃~125℃.

During the test, there is no error at room temperature, the temperature data is stable.

When high temperature testing, temperature data have error, then automatically return to normal.

Some data as follows:

(Ur5：Voltage of R5；Iexc0：Current of IEXC0；Urtd：Voltage of Thermistor（RTD）R（Resistance of Thermistor（RTD）；T：Temperature )

Iexc0=0.000207A,Ur5=1.161035V,Urtd=0.024349V,R=117.440910r

T=47.1

Iexc0=0.000207A,Ur5=1.160784V,Urtd=0.024522V,R=118.303215r

T=49.3

Iexc0=0.000207A,Ur5=1.160548V,Urtd=0.024690V,R=119.137924r

T=51.3

Iexc0=0.000207A,Ur5=1.160430V,Urtd=0.024847V,R=119.904495r

T=1147.9

Iexc0=0.000214A,Ur5=1.200000V,Urtd=0.114293V,R=533.369019r

T=1153.4

Iexc0=0.000214A,Ur5=1.200000V,Urtd=0.114737V,R=535.439270r

T=1155.7

Iexc0=0.000214A,Ur5=1.200000V,Urtd=0.114924V,R=536.314270r

T=1136.4

Iexc0=0.000214A,Ur5=1.200000V,Urtd=0.113361V,R=529.017700r

T=60.6

Iexc0=0.000208A,Ur5=1.165752V,Urtd=0.025709V,R=123.500931r

T=64.2

Iexc0=0.000207A,Ur5=1.159011V,Urtd=0.025845V,R=124.875206r

T=65.7

The other board didn't have the error , so I guess the key is the hardware of this board . Please give advice.

Hi,

The reference is 1.2 volts is it not? And your results are showing Ur5 = 1.2V, so it's likely that the voltage is above 1.2V but it's getting clamped to 1.2V by the ADC.

The ADuCM360 is qualified up to 125 degrees.

It is possible that the device got damaged but it's hard to say remotely.

Regards,

Alex