Abstract: Embodiments of the present invention provide an electronic device. The electronic device includes a circuit board. A first circuit is disposed on a first side of the circuit board. The first circuit is connected to a first ground plane of the circuit board. A second circuit is disposed on a second side of the circuit board. The second side is opposite the first side, and the second circuit is connected to a second ground plane of the circuit board. Moreover, the first and second ground planes respectively lie in different planes of the circuit board and are electrically interconnected by a conductive trace disposed within the circuit board.

Abstract: A protection circuit for a DSL transceiver unit includes a capacitor connected in series between a first and second portion of a primary winding of a transformer. The first and second portions are coupled to first and second lines, respectively, of a twisted-pair telephone line. A first voltage controlled device is coupled to the first line and a chassis ground. The first voltage controlled device has a first threshold turn-on voltage at which the first voltage controlled device provides a first current path from the first line to chassis ground. A resistive device and a second voltage controlled device are coupled across the capacitor in series. The second voltage controlled device has a second threshold turn-on voltage at which the second voltage controlled device provides a second current path from a first capacitor terminal of the capacitor to a second capacitor terminal of the capacitor. The second threshold turn-on voltage is lower than the first threshold turn-on voltage.

Abstract: A protection circuit for a DSL transceiver unit includes a capacitor connected in series between a first and second portion of a primary winding of a transformer. The first and second portions are coupled to first and second lines, respectively, of a twisted-pair telephone line. A first voltage controlled device is coupled to the first line and a chassis ground. The first voltage controlled device has a first threshold turn-on voltage at which the first voltage controlled device provides a first current path from the first line to chassis ground. A resistive device and a second voltage controlled device are coupled across the capacitor in series. The second voltage controlled device has a second threshold turn-on voltage at which the second voltage controlled device provides a second current path from a first capacitor terminal of the capacitor to a second capacitor terminal of the capacitor. The second threshold turn-on voltage is lower than the first threshold turn-on voltage.

Abstract: Embodiments of the present invention provide an electronic device. The electronic device includes a circuit board. A first circuit is disposed on a first side of the circuit board. The first circuit is connected to a first ground plane of the circuit board. A second circuit is disposed on a second side of the circuit board. The second side is opposite the first side, and the second circuit is connected to a second ground plane of the circuit board. Moreover, the first and second ground planes respectively lie in different planes of the circuit board and are electrically interconnected by a conductive trace disposed within the circuit board.

Abstract: A channel card for communicating asymmetric digital subscriber line (ADSL) traffic over a communication line is provided. The channel card includes an asynchronous transfer mode (ATM) section that provides an interface to a cell bus of a chassis and provides ATM processing of cells. The channel card also includes a transceiver section that is coupled to the ATM section. The transceiver section includes at least one subscriber port. The transceiver section provides for modulation and demodulation of data for the at least one subscriber port. The transceiver section includes a common mode choke for reducing noise on the communication line.

Abstract: Circuit modules for providing digital or analog outputs from computational devices in such a manner that the components of the output circuit modules are tolerant of malfunctions in one or more of the components. In the digital output embodiment of the invention, output signals are independently derived using two voting circuits and are then applied to two switches connected in series to provide a fail-safe condition for most types of failure of the switches or the voting circuits. Two identical modules provide the ability to faithfully follow commanded on or off signals in all but a statistically small number of situations, and permit convenient replacement of a defective module without affecting output through the other module. In an analog output module, two independent voting circuits provide voted digital outputs to separate digital-to-analog converters, the outputs of which are compared to generate a validity signal that is used to control an output switch.