A circuit (200) includes: a diode bridge (210) having polarity-independent input terminals for coupling to a DALI bus, and having positive and negative output terminals, wherein the diode bridge receives a receive signal from the DALI bus; a galvanic isolation device (220) having an input for receiving the receive signal from the diode bridge, and an output for outputting the receive signal galvanically isolated from the diode bridge and the DALI bus; a receive signal threshold reference device (235) for setting a threshold voltage for the galvanic isolation device to respond to the receive signal; an amplifier (280) for receiving the galvanically isolated receive signal from the galvanic isolation device and outputting a binary digital signal via a low pass filter (290); and a first duty cycle control device (230, 270) for adjusting the timing of rising edges of the galvanically isolated receive signal with respect to its falling edges.