A logic signal isolator comprising a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals.

Signal isolators using micro-transformers

A receiver or receiver system for high speed data communications having a radio frequency noise canceller (112) is disclosed. The radio frequency noise canceller (112) removes radio-frequency noise from received signals over a transmission medium by adaptively estimating the radio-frequency noise during data transmission. In one embodiment, the radio frequency noise canceller includes: an adaptive filter (208) for producing a noise cancellation signal by filtering a reference noise signal based on filter parameters, a subtractor (202) for subtracting the noise cancellation signal from the first signal to produce the second signal; and an update circuit (204) for enabling, at predetermined times, modification of the parameters of the adaptive filter based on the then existing second signal. A method for removing radio frequency noise is also disclosed.

Radio frequency noise canceller

An apparatus comprising a functional circuitry on a first die. Said function circuitry configured to drive an RF voltage isolation link with an RF signal responsive to receipt of a logic signal at a first logic state. Control circuitry modifies the frequency of the RF signal to spread harmonics to other than a fundamental frequency.

Spread spectrum isolator

Coil structures and isolators using them. A coil(s) is (are) used as a magnetic field-generating element(s) paired with another coil(s) or other magnetic field-receiving element(s). The coil(s) is(are) formed in or on a substrate which does not include some or all of the driver (i.e., input) or receiver (i.e., output) circuits. The coil(s) and magnetic field-receiving element(s) thus can be manufactured separately from the driver and/or receiver circuitry, using different processes, instead of subjecting the chip areas containing both input and output circuits to post processing to form the coil(s). Isolators can be assembled using such coils with a resultant lower cost. Isolators also can be assembled using transformers made from such coils wherein the transformers can be driven on either of their windings in order to provide bi-directional isolation with a single transformer.

Chip-scale coils and isolators based thereon

A component coil for constructing transformers and the transformer constructed therefrom are disclosed. The component coil includes a substrate having an insulating layer of material having top and bottom surfaces. First and second traces are included on the top and bottom surfaces. Each trace includes a spiral conductor. The inner ends of the spiral conductors are connected by a conductor that passes through the insulating layer. The first and second spiral conductors are oriented such that magnetic fields generated by the first and second spiral conductors have components perpendicular to the top surface and in the same direction. The component coils can be used to construct a power transformer or a galvanic isolator.

Miniature transformers adapted for use in galvanic isolators and the like

A termination is provided for a differential transmission line such as unshielded twisted pair (UTP) to isolate a connected device from electromagnetic interference present on the UTP in the form of differential mode and common mode noise. An example of an electromagnetic interference isolator comprises a common mode and a differential mode termination, a common mode choke which exhibits substantially constant impedance over a wide bandwidth and a centre tapped isolation transformer.

Electromagnetic interference isolator with common mode choke

Line termination for multiple differential transmission lines

A termination is provided for a differential transmission line such as unshielded twisted pair (UTP) to isolate a connected device from electromagnetic interference present on the UTP in the form of differential mode and common mode noise. An example of an electromagnetic interference isolator comprises a common mode and a differential mode termination (24, 25), a common mode choke (26) which exhibits substantially constant impedance over a wide bandwidth and a centre tapped isolation transformer (27).

Lewis Freeth Harpham

Papers

Electromagnetic interference isolator with common mode choke

Line termination for multiple differential transmission lines

Electromagnetic interference isolator