Tool/software:
We are using the ADS114S08B to design a 4-wire PT100 circuit. The design utilizes AIN8 as a constant current source (IDAC1), intended to provide a 1mA excitation current to the PT100 sensor. However, upon startup, the system consistently fails to output correct temperature data. The root cause has been isolated: the 1mA constant current source on AIN8 is not activating.
The software configuration sequence, derived from the system's debug logs, is as follows:
[GET] device id = 0xc [GET] cmd config status = 0x80 [SET] cmd config status = 0x0 [SET] cmd config input multiplexer = 0x1 [SET] cmd config gain = 0xb [SET] cmd config data rate = 0x14 [SET] cmd config reference = 0x10 [SET] cmd config idacmag = 0x7 [SET] cmd config idacmux = 0x28 [SET] cmd config vbias = 0x0 [SET] cmd config sys = 0x10 [SET] cmd config gpio data = 0x0 [SET] cmd config gpio con = 0x0 spi read ctrl u16Value = 0x1001 spi read ctrl u16Value = 0x10011335