Patent ID: 7327170
Filing Date: 2008-02-05
Classification: G09G,H03F,H03K

Abstract:
1. A current driver outputting an output current having a current value according to the current value of a reference current, the current driver comprising: a current-voltage converter connected between a first node and a second node and outputting a voltage having a voltage value according to the current value of the reference current; a bias voltage generating transistor provided between the first node and the second node and connected in series with the current-voltage converter; a driving transistor connected between the second node and an output current node at which the output current is output; a third node at which a given voltage is generated; a differential amplifier supplying a voltage having a voltage value according to the difference between a voltage at an interconnecting node provided between the current-voltage converter and the bias voltage generating transistor and a voltage at the third node to each gate of the bias voltage generating transistor and the driving transistor; and a connection switching circuit, wherein the current-voltage converter includes a first and second transistor each having a gate connected to a reference node receiving the reference current and each having a source connected to the first node, and wherein the connection switching circuit switches between a first connection state in which a drain of the first transistor is connected to the reference node while a drain of the second transistor is connected to the interconnecting node and a second connection state in which a drain of the first transistor is connected to the interconnecting node while a drain of the second transistor is connected to the reference node.