Abstract: An electronic apparatus capable of transmitting data at two or more different data rates contains transmitter circuitry, a cable connection mechanism, and an isolation transformer having a primary winding and a secondary winding. The transmitter circuitry low-pass filters digital data which the transmitter circuitry transmits to the primary winding at a first data rate. The transmitter circuitry also transmits digital data to the primary winding at a second data rate different from, typically greater than, the first data rate. The cable connection mechanism provides outgoing data from the secondary winding to the communication cable. Importantly, the transmitter circuitry is operable to generate current-sourced data signals at both data rates and then to convert the current-sourced signals into impedance-produced voltage signals that constitute the outgoing data. Current-source amplifier circuitry normally generates the current-sourced signals.

Abstract: A data transmission method entails differentially transmitting low-pass filtered first outgoing data to and through an isolation transformer at a first data rate. Second outgoing data is differentially transmitted to and through the transformer in the same direction as the first outgoing data but at a second data rate different from, typically greater than, the first data rate. The so-transmitted first and second outgoing data is coupled from the transformer to a communication cable during different time intervals. A related data reception method involves coupling incoming data from a communication cable to and through the isolation transformer and providing the so-coupled incoming data differentially along data transfer paths that extend from the transformer to and through where data moving at the first data rate is received to where data moving at the second data rate is received such that the data transfer paths have a largely constant characteristic impedance.

Abstract: A data-transmitting apparatus contains first and second transmitters, a transmit transformer, and a connecting unit for coupling the transformer to an outgoing twisted-pair cable. The first transmitter filters data to produce outgoing data transmitted to the transformer at a first data rate. The second transmitter transmits outgoing data to the transformer at a different, typically greater, second data rate. A data-receiving apparatus contains first and second receivers, a receive transformer, and a connecting unit for coupling an incoming twisted-pair cable to the receive transformer. The first and second receivers receive incoming data from the secondary winding respectively at the first and second data rates. Incoming data is typically provided along data transfer paths that extend from the receive transformer in a daisy chain manner to the receivers. Data moving at either data rate can be transmitted and received without the need for hot switching in the data paths.

Abstract: A symmetrical non-linear network for use in a function generator in which one or other of a pair of transistors is brought progressively into conduction by a non-linear network, so as to present a low dynamic resistance between the terminals. The non-linear network preferably includes a pair of diodes having a lower turn on voltage than that of the associated transistors, for example Schottky diodes with silicon transistors.The invention also provides a function generator incorporating the above non-linear network for converting square waves to sine waves in which the amplitude of the input signal to the network is controlled automatically.