A reverse power feeding PSE in electrical communication with a DPU, the PSE constituted of: a control circuitry; and a detection and classification signal circuitry, arranged to: output a detection signal; output a classification signal; and output an additional signal exhibiting a voltage below an operating range, and wherein the control circuitry is arranged to: responsive to the output first detection signal, detect a valid signature resistance; responsive to the output first classification signal, receive a classification current and determine the class of the DPU; responsive to the output additional signal, detect the absence, or presence, of an off-hook phone; responsive to the detection of the absence of an off-hook phone, and further responsive to the detection of the valid signature resistance, output power exhibiting a voltage within the operating range; and responsive to the detection of the presence of an off-hook phone, not output power.

A ringing suppression circuit applicable to a transmitter module in a controller area network is provided, which includes a CANH driver circuit, a CANL driver circuit, a first operable circuit transmitting a CAN high signal, a second operable circuit transmitting a CAN low signal, and a termination component connected between the first operable circuit and the second operable circuit. By sequentially turning on a first, second, and third transistor of the CANH driver circuit and sequentially turning on a fourth, fifth, and sixth transistor of the CANL driver circuit, conventional ringing phenomenon is effectively suppressed. A plurality of transistors may also be configured for implementing the CANH driver circuit or the CANL driver circuit for further reducing a glitch. The transmitter module employing the proposed ringing suppression circuit is able to pull the bus to a recessive state and meanwhile suppress the ringing and improve the maximum data rate.

In some embodiments, a power converter circuit includes a first power converter coupled between a direct-current (DC) node and a first pair of output nodes. The first power converter may be configured to provide a first power signal having a first phase to the first pair of output nodes. The power converter circuit may also include a second power converter coupled between the DC node and a second pair of output nodes. The second power converter may be configured to provide a second power signal having a second phase to the second pair of output nodes. The second phase and the first phase may differ by an odd multiple of ninety degrees.

In some embodiments, a power converter circuit includes a first power converter coupled between a direct-current (DC) node and a first pair of output nodes. The first power converter may be configured to provide a first power signal having a first phase to the first pair of output nodes. The power converter circuit may also include a second power converter coupled between the DC node and a second pair of output nodes. The second power converter may be configured to provide a second power signal having a second phase to the second pair of output nodes. The second phase and the first phase may differ by an odd multiple of ninety degrees.

A device for detection of a clipped ringing signal includes a ringing generator, a ringing signal adjusting-and-driving section, and a voltage-detection and clipping-judgment section. The ringing signal adjusting-and-driving section receives a ringing signal from the ringing generator. The ringing signal adjusting-and-driving section also receives a gain adjusting signal. The ringing signal adjusting-and-driving section outputs the ringing signal to a subscriber loop after adjusting the gain thereof according to the gain adjusting signal. The voltage-detection and clipping-judgment section is coupled to the subscriber loop to detect the loop voltage waveform of the subscriber loop, and to determine that the ringing signal is clipped when the loop voltage waveform is discontinuous. When the ringing signal is clipped, the voltage-detection and clipping-judgment section sends the gain adjusting signal to drive the ringing signal adjusting-and-driving section to attenuate the gain of the ringing signal.

A device for detection of a clipped ringing signal includes a ringing generator, a ringing signal adjusting-and-driving section, and a voltage-detection and clipping-judgment section. The ringing signal adjusting-and-driving section receives a ringing signal from the ringing generator. The ringing signal adjusting-and-driving section also receives a gain adjusting signal. The ringing signal adjusting-and-driving section outputs the ringing signal to a subscriber loop after adjusting the gain thereof according to the gain adjusting signal. The voltage-detection and clipping-judgment section is coupled to the subscriber loop to detect the loop voltage waveform of the subscriber loop, and to determine that the ringing signal is clipped when the loop voltage waveform is discontinuous. When the ringing signal is clipped, the voltage-detection and clipping-judgment section sends the gain adjusting signal to drive the ringing signal adjusting-and-driving section to attenuate the gain of the ringing signal.

A system and method for processing a plurality of channels, for example audio channels, in parallel is provided. For example, a plurality of telephony channels are processed in order to detect and respond to call progress tones. The channels may be processed according to a common transform algorithm. Advantageously, a massively parallel architecture is employed, in which operations on many channels are synchronized, to achieve a high efficiency parallel processing environment. The parallel processor may be situated on a data bus, separate from a main general purpose processor, or integrated with the processor in a common board or integrated device. All, or a portion of a speech processing algorithm may also be performed in a massively parallel manner.

A system and method for processing a plurality of channels, for example audio channels, in parallel is provided. For example, a plurality of telephony channels are processed in order to detect and respond to call progress tones. The channels may be processed according to a common transform algorithm. Advantageously, a massively parallel architecture is employed, in which operations on many channels are synchronized, to achieve a high efficiency parallel processing environment. The parallel processor may be situated on a data bus, separate from a main general purpose processor, or integrated with the processor in a common board or integrated device. All, or a portion of a speech processing algorithm may also be performed in a massively parallel manner.

A communication device includes: a signal generator configured to generate a first signal and supply the first signal to a telephone line; a terminator having a variable terminal impedance as seen from the telephone line; a detector configured to detect a difference between the terminal impedance and a line impedance of the telephone line; and a controller configured to determine the terminal impedance so that the difference is reduced.

A communication device includes: a signal generator configured to generate a first signal and supply the first signal to a telephone line; a terminator having a variable terminal impedance as seen from the telephone line; a detector configured to detect a difference between the terminal impedance and a line impedance of the telephone line; and a controller configured to determine the terminal impedance so that the difference is reduced.