Patent ID: 7064696
Filing Date: 2006-06-20
Classification: G05F,H03M

Abstract:
1. A current drive circuit comprising: a current source that produces a varying source current; an output current control circuit that temporarily supplies a boost current having a value corresponding to that of the source current; a current output circuit that amplifies the source and boost currents in accordance with an external signal, the current output circuit comprising: a first switching element that has switch poles respectively connected to a current output part of the first current mirror circuit and a first power supply voltage; and a second switching element that has switch poles respectively connected to a current input part of the second current mirror circuit and a second power supply voltage, wherein: the first and second switching elements switch and operate in opposite phases in accordance with the external signal, the first switching element raises an output current of the first current mirror circuit when turned on, the second switching raises an output current of the second current mirror circuit when turned off, and the output current control circuit temporarily supplies the boost current at a time of rise in the drive circuit output current so as to increase the rate of rise in the drive circuit output current.