So I can easily make standalone temperature device but I want to produce 4-20ma also output corresponding to the temperature ... I wanted to interface PT100 which 100Ohm RTD. TMP112 is the on chip ...

We're now in the process of implementing HART in several of our loop-powered RTD transmitters by adding the DAC8740H modem ... The XTR115 should be ok to use with implementing HART for the 4-20mA loop ...