DRIVING CIRCUIT OF ORGANIC ELECTRO LUMINESCENCE DISPLAY OF NEGATIVE VOLTAGE DRIVING METHOD

摘要

PURPOSE: A driving circuit of an OELD(organic electro luminescence display) of a negative voltage driving method is provided to drive an OELD panel using a symmetric waveform by including a negative voltage into a driving waveform. CONSTITUTION: The driving circuit includes an SMPS(Switching Mode Power Supply) part(10) supplies a supply voltage(Vsupply) to maintain a constant voltage difference of voltage supplied from the power supply with a fixed voltage, and a driver integrated circuit output part(20) generates a negative voltage by the supply voltage supplied from the SMPS part and transfers voltage and current to the OELD panel. The SMPS part is an insulating DC-DC converter using a transformer and supplies a bias of the supply voltage needed in the driver integrated circuit output part. The driver integrated circuit part makes an output(Vout) of an output stage as constant negative voltage or positive voltage through a switching operation of a PMOS transistor(Qp2) and an NMOS transistor(Qn3) of the output stage, using voltage difference between the supply voltage from the SMPS part and a ground voltage(Vground) and a constant DC voltage.