Patent ID: 6249148
Filing Date: 2001-06-19
Classification: H03K

Abstract:
An output circuit for propagating an electrical signal from an input node to an output node, wherein the output circuit is couplable between a high-potential power rail and a low-potential power rail, wherein the output circuit includes an enable node for receiving an enable signal, and a bipolar pulldown transistor having a collector coupled to the output node, the circuit comprising:a. a control transistor having a control node coupled to the enable node and a high-potential node coupled to the high-potential power rail;b. a base drive branch having a high-potential node coupled to a low-potential node of the control transistor and a low-potential node coupled to the base of the bipolar pulldown transistor; andc. a base-current regulating branch having a high-potential node coupled to said low-potential node of said control transistor and a low-potential node coupled to the output node of the circuit, wherein said base-current regulating branch regulates current delivered to the base of the bipolar pulldown transistor.