The TDA 4817 contains all functions for designing electronic ballasts and switched-mode power supplies with sinusoidal line current consumption and a power factor approaching 1. The TDA 4817 controls a boost converter as an active harmonic filter in a discontinuous (triangular shaped current) mode with variable frequency. A typical application is in electronic ballasts, especially when a large number of such lamps are concentrated on one line supply point. The output voltage of this filter is regulated with high efficiency. Therefore the device can be easily operated on different line voltages (110/220 VAC) without any switchover. The TDA 4817 is an 8-pin-economy-version of the TDA 4814 A without reference voltage output and start/stop monitoring circuit.