Apparatus and method for reducing noise in a system using single ended signal transmission

A method for reducing a common noise voltage when receiving at least one single ended signal, the method comprising:

• receiving, at a receiving circuit whose ground reference is a ground plane of the receiving circuit, one or more single ended signals whose voltage level changes, from a transmitting circuit whose ground reference is a ground plane of the transmitting circuit;
• in response to receiving the one or more single ended signals whose voltage level changes, generating a noise generating current flowing from the receiving circuit to the transmitting circuit through an inductance in a return path from the receiving circuit to the transmitting circuit;
• and
• using the one or more single ended signals whose voltage level changes, generating a first noise cancelling current flowing through the inductance in the return path in a direction opposite to a flow of the noise generating current through the inductance.

An apparatus for reducing common mode noise in single ended digital data, the apparatus comprising:

• an inverter circuit configured to receive N single ended signals transmitted to N input impedances of receiving circuitry, wherein N is an integer greater than zero;
• and
• N compensation impedances, wherein a first port of each of the N compensation impedances is electrically coupled to a unique output port of the inverter circuit, and wherein a second port of each of the N compensation impedances is electrically connected to all other second ports of other compensation impedances and to a first or a second ground plane;
• wherein the inverter circuit is configured to invert a single ended signal received at each input port of the inverter circuit to provide each single ended signal which has been inverted to a unique compensation impedance of the N compensation impedances;
• wherein in response to receiving each single ended signal which has been inverted, the N compensation impedances are configured to generate a noise cancelling current which is summed with a noise generating current, generated in the N input impedances of the receiving circuitry, to form a sum current which flows through an inductance in a return path electrically coupling the first and the second ground planes and whose magnitude is less than a magnitude of the noise generating current.