US 5,945,878 A · Single-ended to differential converter

Abstract

A single-ended to differential converter (400, 500) has an input terminal (418, 518) which is adapted to be coupled to an inductance (412, 512). A first transistor (402, 502) which terminates an input signal received at the input terminal according to its transconductance has a first current electrode coupled to the input terminal. A second current electrode of the first transistor (402, 502) outputs one current of a differential output current. A second transistor (404, 504) has a control electrode coupled to the input terminal, a first current electrode coupled to a signal ground terminal, and a second current electrode for providing another current of the differential output current. Bias circuits bias the control electrodes of the first (402, 502) and second (404, 504) transistors to maintain the same DC currents through their current electrodes. The single-ended to differential converter (400, 500) reflects the noise produced by the first transistor (402, 502) in the second transistor (404, 504), and this common-mode noise can be rejected in a subsequent stage.

Claims20

Dependent claims

A single-ended to differential converter comprising:

an input terminal for receiving an input voltage and adapted to be coupled to an inductance which exists between said input terminal and a first signal ground;
a first transistor having a first current electrode coupled to the input terminal, a control electrode, and a second current electrode for providing a first current output signal;
a second transistor having a first current electrode coupled to a second signal ground, a control electrode coupled to the input terminal, and a second current electrode for providing a second current output signal, wherein said first and second current output signals form a differential current therebetween representative of an input voltage signal on the input terminal;
a first bias circuit coupled to said control electrode of said first transistor, wherein said first bias circuit biases said control electrode of said first transistor to have a predetermined transconductance;
and
a second bias circuit coupled to said control electrode of said second transistor, wherein said second bias circuit biases said control electrode of said second transistor to have said predetermined transconductance.

3 more elements

Dependencies are inferred from the claim text.

Single-ended to differential converter

Life of this patent

Single-ended to differential converter

Life of this patent

Abstract

Claims20