Drive unit for actuating a parking brake in a vehicle

A compact drive unit for actuating parking brakes is provided. The drive unit has a reduction gear that is formed by a two-stage belt drive, in combination with a drive motor that is made up of a brushless direct current motor. The two-stage belt drive preferably consists of two toothed belt drives functionally arranged in series; the direct current motor preferably has an external rotor with a rare-earth magnetic ring.