Patent ID: 6720830
Filing Date: 2004-04-13
Classification: H03F

Abstract:
A complimentary metal oxide semiconductor (CMOS) differential amplifier, comprising:a first transistor including a first node coupled to a voltage source, and a second node and a gate node coupled to each other, such that said first transistor is configured as a self-biased current source; a second transistor including a first node coupled to the voltage source, and a second node and a gate node coupled to each other, such that said second transistor is configured as a self-biased current source; a third transistor including a first node coupled to the second node of said first transistor and serving as a first output node, a second node, and a gate node serving as a first input node and configured to receive a first input signal; a fourth transistor including a first node coupled to the second node of said second transistor and serving as a second output node, a second node coupled to the second node of said third transistor, and a gate node serving as a second input node and configured to receive a second input signal; and a fifth transistor including a first node coupled to the second nodes of said third and fourth transistors, a second node coupled to ground, and a gate node configured to receive a bias signal such that said fifth transistor operates as a current source; wherein gate threshold voltages of said third and fourth transistors are greater than gate threshold voltages of said first, second and fifth transistors.