In a scan lines driver that is used for driving scan lines of an organic light emitting diodes (OLED) display, a large voltage drop can develop between the gate or source of one of its transistors and the corresponding drain during a scan signal outputting period. This large voltage drop can excessively stress the one transistor. However, in accordance with the present disclosure, a voltage drop dissipating, second transistor is provided in series with the first transistor for absorbing part of the large voltage drop and thus reducing the stress that is applied to the first transistor.