Output circuit free from overshoot and undershoot on signal lines alternately driven in positive potential range and negative potential range

摘要

An output circuit of a liquid crystal display driver has a first operational amplifier fast in potential rise and slow in potential decay and a second operational amplifier fast in potential decay and slow in potential rise both serving as voltage followers, and the first operational amplifier and the second operational amplifier are alternately connected to a data line of a liquid crystal display panel so as to alternate the potential level on the data line between a positive range and a negative range with respect to a reference voltage level on a common electrode of the pixels at changes of horizontal periods, wherein a reset circuit is connected to the first and second operational amplifiers so as to forcibly reset the non-inverted nodes and the output nodes to the reference voltage level in each transient period between the horizontal periods, thereby eliminating undershoot and overshoot due to the slow potential change from the potential waveform on the data line.