Patent ID: 7564638
Filing Date: 2009-07-21
Classification: G11B,H03F

Abstract:
1. An amplifier circuit, comprising: a first differential amplifier circuit, the first differential amplifier circuit being asymmetric with respect to transistor type and having a first pair of inputs and a first pair of outputs; a second differential amplifier circuit, having a second pair of inputs and a second pair of outputs, the second pair of outputs coupled to the first pair of outputs of the first differential amplifier circuit, the second differential amplifier circuit being asymmetric with respect to transistor type; wherein: a first bias circuit coupled to the first differential amplifier circuit, for setting an operating condition of the first differential amplifier circuit; and a second bias circuit coupled to the second differential amplifier circuit, for setting an operating condition of the second differential amplifier circuit, wherein the first bias circuit comprises a first bias transistor connected in a current mirror configuration with the first transistor, and the second bias circuit comprises a second bias transistor connected in a current mirror configuration with the third transistor.