I have been using ImageMagick for quite a sometime. It's very nice tool with a lot of features.
Install ImageMagick and run following command. This is what I used on Linux, you may have to replace convert with the correct one.
Below command converts PDFs to CCITT Group 3 standard TIFs (Fax standard):
convert -define quantum:polarity=min-is-white \
-endian MSB \
-units PixelsPerInch \
-density 204x196 \
-monochrome \
-compress Fax \
-sample 1728 \
"input.pdf" "output.tif"
Also you may use GraphicsMagick, it is also similar to ImageMagick, but ImageMagick more concerns with quality than speed.