| 摘要 |
PURPOSE:To indenpendently change values of poles and zero points obtained at an operational amplifier to poles higher in frequencies, by providing the 1st and 2nd frequency compensating circuits, each of which is composed of a capacity and MOSFETs in the operational amplifier circuit. CONSTITUTION:The 2nd frequency compensating circuit composed of a capacity 8 and MOSFETs 9 and 10 is constituted as shown in the figure in addition to a conventional frequency compensating circuit composed of a capacity 4 and MOSFETs 5 and 6. When the two frequency compensating circuits are provided, values of poles higher in frequencies and zero points can be changed without changing values of a main pole and the 2nd pole. An MOSFET20 and MOSFETs 18 and 21 respectively constitute the 1st and 2nd and 3rd constant- current sources and a ground line GL and line 7 respectively constitute the 1st and 2nd constant-voltage sources. |
