Patent ID: 7199655
Filing Date: 2007-04-03
Classification: H03F

Abstract:
1. A multistage amplifier circuit comprising: a first amplifier having a first power supply terminal connected to a ground potential, a second power supply terminal supplied with a first supply voltage, a non-inverting input terminal supplied with a reference voltage, and an inverting input terminal supplied with an input signal via a first resistor, the first amplifier amplifying the input signal for output; a second resistor for feedback use to connect between the output side of the first amplifier and the inverting input terminal of the first amplifier; a second amplifier having a first power supply terminal connected to the ground potential, a second power supply terminal supplied with a second supply voltage higher than the first supply voltage, a non-inverting input terminal supplied with the reference voltage, and an inverting input terminal supplied with an output signal from the first amplifier via a third resistor, the second amplifier amplifying the output signal for output; a fourth resistor for feedback use to connect between the output side of the second amplifier and the inverting input terminal of the second amplifier; and a fourth resistor connected between the inverting input terminal of the second amplifier and the ground potential.