Realtek Semiconductor Inc.

Realtek Semi-conductor Co., Ltd.

Chen-Chih Huang

Pao-Cheng Chiu

Chih-Wen Huang

Ming-Yuh Yeh

Cheng-Pang Chan

Chao-Cheng Lee

Chien-Ming Wu

Yu-Chang Chen

Tay-Her Tsaur

Jia-Ching Shen

Wei-Chou Wang

Ming-Han Lee

Mu-Jung Chen

Chin-Wen Huang

Iat-In Ao-Ieong

Chao-Hsiou Hsu

Sheng-Huang Tsao

Tsung Yen Tsai

The present invention discloses an EMI suppression device, comprising: a first transformer including a first circuit-end central tap to receive a first circuit signal from two first circuit-end signal taps, and a first cable-end central tap to receive a first cable signal from two first cable-end signal taps; a second transformer including a second circuit-end central tap to receive a second circuit signal from two second circuit-end signal taps, and a second cable-end central tap to receive a second cable signal from two second cable-end signal taps; a first circuit-end inductor coupled between the first circuit-end central tap and a system ground to reduce the common mode noise of the first circuit signal; and a second circuit-end inductor coupled between the second circuit-end central tap and the system ground to reduce the common mode noise of the second circuit signal. Said first and second circuit-end inductors operate separately.

EMI suppression device and method for network transmission

An oscillator and the control method thereof. The oscillator includes an oscillation unit to receive a first current and to generate an oscillating signal according to the first current, a frequency-to-voltage converter to receive the oscillating signal and to generate a converted voltage according to a frequency of the oscillating signal, and a voltage-to-current converter to receive the converted voltage and to generate the first current according to the converted voltage, wherein the first current is modulated from a first value to a second value after the initiation of the oscillation unit.

Oscillator and control method thereof

The multi-channel power supply comprises a first channel, a second channel, a current sensing module, a current average control circuit, and a modulator. The first channel and the second channel respectively transform an input voltage into an output voltage according to a first pulse width modulation (PWM) signal and a second PWM signal. The current sensing module respectively sense a first channel current and a second channel current to output a first sensing current and a second sensing current. The current average control circuit generates a first error current and a second error current according to the first sensing current and the second sensing current and an average current thereof. The modulator generates the first PWM signal and the second PWM signal according to the first error current, the second error current and the output voltage.

Multi-channel power supply and current balancing control method thereof

A switched-mode power supply (SMPS) uses an equivalent inductor of bonding wire(s) and lead frame(s) to replace a traditional external inductor. A current-controlled pulse width modulation (PWM) modulator and a current-controlled pulse frequency modulation (PFM) modulator are optionally employed for high frequency switching, so as to mate a low inductance value of the bonding wire(s) and lead frame(s) and achieve reduced cost, low power consumption and low complexity.

Switched-mode power supply

A signal generating apparatus comprises an amplifier, which comprises differential input terminals for receiving a first input signal, a common mode output signal adjusting terminal for receiving a second input signal, and an output terminal. The signal generating apparatus may provide two or more differential output signals according to the first input signal, and provide two or more common mode output signals according to the second input signal. The amplifier provides an output signal comprising one of the differential output signals and one of the common mode output signals at the output terminal.

Signal generating apparatus and method thereof

A frequency detection apparatus and method are provided. The frequency detection apparatus includes a frequency conversion circuit and an analog conversion circuit. The frequency conversion circuit receives an input clock, and generates an analog signal corresponding to a frequency of the input clock based on the frequency of the input clock. The analog conversion circuit is coupled to the frequency conversion circuit, receives the analog signal, and generates a discriminating signal corresponding to the frequency of the input clock based on the analog signal, where the discriminating signal represents a frequency interval of the input clock.

Frequency detection apparatus and method

The invention discloses a sink device and a signal receiving method thereof, applicable to wireless local area network. The sink device receives a plurality of beacon signals, synchronizes the beacon output signal generated by itself with the operating clock of the source device according to the above-mentioned timing synchronization data. And the sink device receives the plurality of beacon signals according to this calibrated synchronization clock.

Sink device for a wireless local area network

This invention discloses a clock generator capable of automatically adjusting output clock when process, voltage, or temperature variation occurred. The clock generator comprises a current generator, for generating a first current and a second current according to a control voltage; a oscillator, coupled to the current generator, for generating a clock signal according to the first current; and a voltage adjuster, coupled to the current generator and the oscillator, for adjusting the control voltage according to the clock signal and the second current; wherein, when the signal frequency of the clock signal changed, the voltage adjuster correspondingly adjusts the control voltage so as to adjust the first current.

Clock generator

An apparatus for echo cancellation in a transceiver of a full duplex communication system, where the transceiver includes a transmitter for transmitting a transmit signal and a receiver for receiving a receive signal, includes: an echo cancellation signal generator, coupled to the transmitter, for receiving the transmit signal and for generating an echo cancellation signal according to the transmit signal, wherein the echo cancellation signal reflects an effect of an impedance of a channel and a parasitic capacitor of the transceiver; and a calculation module coupled to the transmitter, the receiver, and the echo cancellation signal generator for receiving the receive signal and for canceling the echo of the receive signal according to the echo cancellation signal to generate an echo-cancelled signal, wherein the effect of the impedance of the channel and the parasitic capacitor of the transceiver in the echo-cancelled signal is reduced.

Echo cancellation device for full duplex communication systems

A transceiver in a full duplex communication system includes a hybrid circuit for transmitting a transmission signal or receiving a receive signal via the channel, the hybrid circuit includes an echo cancellation device for removing transmission signal components from the receive signal; wherein the hybrid circuit outputs a processed receive signal; and a gain amplifier being an OP-RC AGC is directly connected to the hybrid circuit for amplifying the processed receive signal, wherein a first node of the gain amplifier coupled to the echo cancellation device is a virtual ground.

Transceiver for full duplex communication systems

The present invention discloses a digital-to-analog converter (DAC), including a bias voltage generating unit, a digital-to-analog converting stage, and an operating amplifier. The bias voltage generating unit is utilized for generating a first bias voltage. The digital-to-analog converting stage is utilized for converting a digital signal into a voltage signal, the digital-to-analog converting stage includes a current source for providing a current, and a switching unit is coupled to the current source for controlling the current to pass the switching unit according to the digital signal, and a load. The current flows through the load to generate the voltage signal. The operating amplifier is coupled to the bias voltage generating unit and the digital-to-analog converting stage for controlling the current source according to the first bias voltage.

Digital-to-analog converter

A transmission line driver for generating an output signal to drive a transmission line is disclosed. The transmission line driver includes a voltage driver and a current driver. The voltage driver generates a voltage signal to drive the transmission line. The current driver generates a current signal to drive the transmission line. The amplitude of the output signal is determined according to the voltage signal and/or the current signal.

Transmission line driver

An echo cancellation apparatus of a transceiver in a full duplex communication system is disclosed. The full duplex communication system includes a transmitter section for transmitting a transmit signal and a receiver section for receiving a receive signal. The echo cancellation device includes an echo cancellation signal generator coupled to the transmitter section for receiving the transmit signal and for generating an echo cancellation signal according to the transmit signal, a load resistor and a parasitic capacitor of the transceiver; and a calculation module coupled to the transmitter section, the receiver section, and the echo cancellation signal generator for receiving the receive signal and for eliminating at least high frequency components of the echo signal.

A network device comprises a hybrid-mode transmitter for transmitting a differential transmission signal at a first transmission rate or a second transmission rate. The network device includes a first mode channel and a second mode channel. The first mode channel includes a voltage mode driver and a current mode driver for outputting the differential transmission signal. The second mode channel includes a second mode driver, which is one of a voltage mode driver and a current mode driver. The network device transmits the differential transmission signal at the first transmission rate through the voltage mode driver of the first mode channel and the second mode driver. The network device transmits the differential transmission signal at the second transmission rate through at least one of the current mode driver and the voltage mode driverfirst mode channel.

Network device with hybrid-mode transmitter

The invention relates to a phase-interpolation circuit and a phase-interpolation signal generating circuit applying the phase-interpolation circuit. The phase-interpolation circuit can avoid short-circuit current effectively. In addition, an inter-phase signal can be interpolated between the rising edge and the falling edge of the clock pulse. The phase-interpolation signal generating device can generate multiphase clock signals which not only have linearly distributed phases but also maintain good 50% duty cycle of the multiphase clock signals.

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Hsin-Chu Hsien, Taiwan

Chen-Chih Huang