Broadcom Corporation

Northern Telecom Limited

Scientific-atlanta, Inc.

Steven L Caine

Charles Garrison Wier

Kevin Lee Miller

Theodore F Rabenko

John H Gleiter

Todd Lee Brooks

William Alva Dunn

William G Daly

Mahlon D Kimbrough

A system and method is provided for supplying power over a home phone line network in a manner that is interoperable with other voice and data services operating on the same network. The system includes a power source coupled to the home phone line network. The power source includes an AC signal generator that generates an AC signal at a selected frequency. The power source also includes a band pass filter for removing unwanted harmonics from the AC signal, thereby generating a filtered AC signal for powering one or more devices on the home phone line network. One or more devices attached to the home phone line network, such as a telephone adapter or telephone, receives the filtered AC signal. Each device comprises a second band pass filter and an AC/DC converter. The second band pass filter passes the filtered AC signal to the AC/DC converter and prevents the introduction of undesired harmonics onto the home phone line network from the AC/DC converter. The AC/DC converter converts the filtered AC signal to a DC signal used for powering the device.

System and method for providing power over a home phone line network

A power output controller includes an output stage, a sensing circuit that compares an output voltage of the output stage with a reference voltage, and a digital controller that controls output pulses that charge the output stage with a frequency that is dependent on an output of the sensing circuit.

Programmable dual mode hysteretic power output controller

A CODEC and a SLIC assembly perform current-sensing-voltage synthesis impedance matching and DC feed control functions. Signal processing that does not require high voltage, such as impedance matching and DC feed control, is performed in the digital domain by the CODEC while the SLIC assembly includes high voltage circuitry. This configuration is useful for Voice over Internet Protocol (VOIP) applications with a short subscriber line loop or other long loop applications. The SLIC includes high voltage operational amplifiers (op amps) to drive ring and tip signals. Bipolar transistors are also provided as bias compensating diodes for bias point stabilization over dynamic operating conditions such as temperature. The high voltage op amps include a composite MOSFET-bipolar complimentary symmetry driver stage that offers the bias control and stability of a bipolar device topology and drive capabilities of a power MOSFET device.

DSP based SLIC architecture with current-sensing voltage synthesis impedance matching and DC feed control

A SLIC assembly includes high voltage operational amplifiers (op amps) and low voltage op amps. The high voltage op amps are used to drive ring and tip signals while the low voltage op amps are used to drive other signals. The low voltage op amps include Class A-B amplifier drivers based on bipolar transistors. Bipolar transistors are also provided as bias compensating diodes for bias point stabilization over dynamic operating conditions such as temperature. The high voltage op amps include a composite MOSFET-bipolar complimentary symmetry driver stage that offers the bias control and stability of a bipolar device topology and drive capabilities of a power MOSFET device.

Methods and systems for a MOSFET-bipolar complimentary symmetry driver with local feedback for bias stabilization

A communication loop using a subscriber line interface circuit (SLIC) is modified such that it can operate in unbalanced ringing environments as well as balanced ringing environments. This is accomplished by grounding the tip lead of a telephone instrument and creating an open circuit at the tip lead of the SLIC. The ring lead of the telephone instrument and the ring lead of the SLIC are electrically connected, and an AC voltage applied to the ring lead by the SLIC is increased. A power supply is connected to the SLIC and biased to provide the increased AC voltage on the SLIC ring lead while the average voltage on the SLIC tip lead is maintained substantially at ground. The result of this circuitry is a trapezoidal signal meeting the amplitude, loading and crest factor requirements of Bellcore Technical Requirement Publications TA-NWT-000909 and TR-NWT-000057.

Unbalanced ringing using a balanced ringing generator of a subscriber

A power converter comprises a power stage including a transformer, a pulse width modulator (PWM) for controlling the power stage, multiple output circuits providing individually regulated voltages, including switches for coupling the output circuits sequentially and cyclically to the power stage, and feedback circuitry for supplying respective feedback signals, each for a respective output circuit, as a control signal to the PWM synchronously with the coupling of the output circuits to the power stage, so that a single PWM and power stage serve for multiple output circuits. The converter can be a dc to dc converter or a four-quadrant switching amplifier. The PWM operates in current mode in conjunction with a current sensing resistor or transformer.

Power converter with plural regulated outputs

A four quadrant current mode switching amplifier is provided. The switching amplifier includes a pulse width modulator (PWM) programmed by an error voltage derived from an analog input voltage and the amplified output voltage. The PWM is also provided with negative current mode feedback in all four quadrants of operation. A logic device controls the switching topology to source, or sink power for the load and to provide negative or positive output in dependence upon sign and slope bits, derived from the input and output voltages, and the PWM output.

Growing community of inventors

Lawrenceville, GA, United States of America

Steven L Caine