If using DSI no alternative available   

Tridonic Electronic compact dimming ballast to run 1 x 26-57w TC Compact

The Tridonic PCA 1×26-57 TC ECO xitec II is a high frequency dimmable ballast for use with DALI DSI switchDIM interfaces.

Compatible with the following lamps:

1 x 40w T5 Circular Lamp

1 x 26w Double Turn Compact Fluorescent Lamp

1  x 26w Triple Turn Compact Fluorescent Lamp

1 x 40w Long Single Turn Compact Fluorescent Lamp

1 x 40w T5 Circular Fluorescent Lamp

1 x 32w Triple Compact Fluorescent Lamp

1 x 42w Triple Turn Compact Fluorescent Lamp

1 x 57w Triple Turn Compact Fluorescent Lamp

Tridonic part number: 22185120