摘要 |
<p>A driving circuit includes a pair of operational amplifiers, one producing an analog voltage output of positive polarity, the other producing an analog voltage output of negative polarity. An output switching circuit interchanges these outputs between a pair of data lines. One or both of the operational amplifiers includes a parasitic diode having one terminal connected to the output terminal of the operational amplifier and another terminal normally connected to a power supply voltage of the operational amplifier. When the output of the operational amplifier is switched, a protective switching circuit temporarily disconnects the parasitic diode from the power supply of the operational amplifier and instead connects it to a power supply line carrying a voltage high enough, or low enough, to ensure that the parasitic diode is not forward biased by the existing voltage on the data line to which the output is switched.</p> |