Patent ID: 6720818
Filing Date: 2004-04-13
Classification: H03K

Abstract:
A multiplexer for providing, at a differential output, a signal received at a selected differential input of a plurality of differential inputs, the multiplexer comprising:a first differential transistor pair, each transistor of the first differential transistor pair having a control port, an input port and an output port, the control ports forming one of the plurality of differential inputs and the input ports connected to a first voltage potential and forming the differential output; a first selection transistor pair, each transistor of the first selection transistor pair having a control port, an input port and an output port, each of the input ports connected to one of the output ports of the transistors of the first differential transistor pair, the output ports of the first selection transistor pair connected to a second voltage potential, the control ports of the first selection transistor pair connected to each other and forming at least a first portion of a select port of the multiplexer; a second differential transistor pair, each transistor of the second differential transistor pair having a control port, an input port and an output port, the control ports forming another of the plurality of differential inputs and the input ports connected to the first voltage potential; and, a second selection transistor pair, each transistor of the second selection transistor pair having a control port, an input port and an output port, each of the input ports connected to one of the output ports of the transistors of the second differential transistor pair, the output ports of the second selection transistor pair connected to a second voltage potential, the control ports of the second selection transistor pair connected to each other and forming at least a second portion of the select port of the multiplexer; wherein the select port is a differential select port, the first portion of the select port and the second portion of the select port for receiving a differential select signal having a select signal and a complementary select signal; and, wherein the output ports are connected to the second voltage source through a current source.