We don't offer one, but it is easy to build.
Just build an HTML page that displays your content comma separated just like you would any other results page. You will have to view source on the page to make sure it looks right. Commas after each value and new lines for each row.
Once you have it formatted properly you can add a header to the top of the page to make it download like a csv file instead of display in the browser like:
// tell the browser we want to save it instead of displaying it
header('Content-Disposition: attachment; filename="csvfilename.csv";');