Patent ID: 6806745
Filing Date: 2004-10-19
Classification: G11C,H03F,H03K,H03M

Abstract:
A load driving sample-and-hold amplification circuit, comprising:a sampling circuit that carries out a sampling of an input signal; and an operational amplifier that carries out an operational amplification of the input signal that has been subjected to the sampling by the sampling circuit, wherein the operational amplifier includes: first and second operational amplifier stages that are connected in this order in a series manner; a first switch, provided between an output terminal of the first operational amplifier stage and an input terminal of the second operational amplifier stage, that connects or cuts off a connection of the first and second operational amplifier stages so as to be nonconductive in a first operation phase during which the sampling is carried out and so as to be conductive in a second operation phase during which the operational amplifier, as a whole, carries out the operational amplification; a capacitor provided between an output terminal and the input terminal of the second operational amplifier stage; and a second switch provided between the output terminal of the second operational amplifier stage and a load, means for causing the second switch to connect or cut off a connection of the second operational amplifier stage and the load wherein the means causes the second switch to be conductive in the first operation phase and nonconductive in the second operation phase so that the second switch is conductive when the first switch is nonconductive, and vice versa, whereby driving time of amplification differs from drive time of the load so that low power consumption is realized.