Hi! I am looking for a linear opto isolator chip with at least 4 channels.
I know the IL300, HCNR200 and the like but as my project involves 8 analog inputs to a PIC mcu, my main concern is to make the analog front end as compact as possible. Making 8 circuits based on the above chips will be bulky and costly. Are there other alternatives?
Thanks for the replies. Please have a look at this link: **broken link removed**
I wish it could be more clear to see the opto chips. That is what I need!
My project is defferent though. I have sensors (0-10 and 4-20mA) that are in a water pump station and want to read the values and send them over a radio modem to the main console station. I prefer the sensors are galvanic isolated.
I have in mind the chips proposed here, but the above link I think rules in matter of size and maybe cost.
why not just change it to a PWM and isolate that? it is expensive to get good linear isolation, but then I am usually looking for 5KV+ isolation.
it is really easy since you are reading it with a micro anyhow. just send a fixed frequency ramp into one input of a comparator and your unknown into the other and feed that into a transmitter (there are some links that will take that directly). If you absolutely must, use a 555 for the ramp and use the micro to take out the RC nonlinearity.
You didn't say what kind of freq response you need, so I presume it's pretty lo freq or DC. If so, you might be able to use these Vactrols ... **broken link removed**