Patent ID: 6300834
Filing Date: 2001-10-09
Classification: H03F

Abstract:
An intermediate stage for a CMOS operational amplifier comprising:a first current mirror receiving first differential inputs and having an first current mirror input;a second current mirror receiving second differential inputs and having a second current mirror input; anda floating current source comprising:a first NMOS transistor (500) having a drain and gate connected in common;a second NMOS transistor (502) having a drain connected to the first current mirror input and having a gate connected to the gate of the first NMOS transistor (500);a first PMOS transistor (503) having a source connected in common with the source of the first NMOS transistor (500) and having a drain coupled to a first power supply terminal;a second PMOS transistor (505) with a source connected to the source of the second NMOS transistor (502), and with a drain connected to the second current mirror input;a first voltage supply (510) having a first terminal coupled to the first power supply terminal and having a second terminal connected to the gates of the first PMOS transistor (503) and the second PMOS transistor (505); anda first current source (508) having a first terminal connected to a second power supply terminal and a second terminal connected to the drain of the first NMOS transistor (500).