Patent ID: 6677784
Filing Date: 2004-01-13
Classification: H03K

Abstract:
A single stack bipolar logic AND gate for low power applications comprising:a first differential pair of transistors, each transistor of said first differential pair having base, emitter and collector terminals, a base of a first transistor of said first differential pair receiving a digital logic input signal A and a base of said second transistor of said first differential pair receiving its complementary digital logic signal {overscore (A)}, said emitters of each transistor of the first differential pair being connected at a common node to a first constant current source; a second differential pair of transistors, each transistor of said second differential pair having base, emitter and collector terminals, a base of a first transistor of said second differential pair receiving a digital logic input signal B and a base of said second transistor of said second differential pair receiving its complementary digital logic signal {overscore (B)}, said emitters of each transistor of the second differential pair being connected at a common node to a second constant current source; a common voltage power supply source, the collector terminal of each said first transistor of said first and second differential pair being connected to said common voltage power supply source through a first resistance and defining a complement output node of said AND gate, and the collector terminal of each said second transistor of said first and second differential pair being connected to said common voltage power supply source through a second resistance and additionally defining an output node of said AND gate, wherein said second resistance is greater than said first resistance.