I remember that when I needed an application to transform TIF files to DWG format (Autocad) I encountered the same problem and, fortunately, I have found one that fits my needs. It's called VectorNow and a trial is obtainable from our website. The software is easy to use: you just download the software, install it using its main installer and start it from your desktop. A simple interface is all you need to get the job done. First select the TIF file, then choose the output version of Autocad file type and some minor configuration. As a next step, click Convert and your new file will be saved where you specified, then you can open the result into your favorite Autocad application.