The MSC1201-xx is a 1/2 duty vacuum fluorescent display tube driver implemented in Bi-CMOS technology. This LSI consists of 64-bit shift registers, 64 latches, PWM conversion circuit, a digital dimming circuit, 30-segment driver and 2-grid driver. As the MSC1201-xx has both a digital dimming circuit and a PWM conversion circuit which converts PWM signal for lamp dimming control to PWM signal for VFD tube dimming control, the dimming control can be realized without any external circuit.