A vane-type camshaft phaser includes a vaned camshaft rotor disposed within a lobed stator, defining phase advance and retard chambers filled with oil. The height of the rotor is less than the height of the stator, providing space for a vaned brake rotor alongside the camshaft rotor. The brake rotor is free to rotate independently of the camshaft rotor. The volume of each advance and retard chamber is a function of the rotational position of both the camshaft rotor and the brake rotor, and the volume of each chamber is constant. Rotation of the brake rotor in one direction causes rotation of the camshaft rotor in the opposite direction. The brake rotor is connected to a controllable brake mechanism. By sensing of the camshaft rotor position and feedback control of the braking mechanism, the camshaft rotor may be maintained at any position.