??? 08/22/10 18:55 Read: times |
#178221 - Frequency to 4-20mA convertion |
Hi Friends, I am working on a online process indicator. for its 4-20mA dc analog output, earlier I was using F-to-V , and V-to-I converters. Means the MCU will give frequency output, then through a opto-isolator it is coupled with a F to V converter and its output voltage is then converted in mA signal with a V-to-I converter stage. I now want to decrease the hardware by using the analog voltage output from the MCU which will be converted in mA with a single Op-Amp stage. [ my silabs MCU has a 12bit DAC output] The question is, what can be done for isolation [requirement is the 4-20mA to be isolated from MCU circuit supply ]. I found the analog isolators HCNR201 and IL300. Is it the good solution or is there any simpler way?. Or is there any such standard device for F-to-I coversion? Any suggestions are welcome. Thanks Anita |