A novel phase locked loop design utilizing novel phase-frequency detector, charge pump, loop filter and voltage controlled oscillator is disclosed. The phase-frequency detector includes a dual reset D-flip flop for use in multi-GHz phase locked loops. Traditional dead zone issues associated with phase frequency detector are improved/addressed by use with a charge transfer-based PLL charge pump.

Frequency synthesizers having reduced phase noise and a small step size. One example can provide frequency synthesizers having low phase noise by eliminating dividers in a feedback path and instead employing frequency converters, such as mixers. Step size can be further reduced by providing frequency converters in a reference signal feedforward path. Acquisition time can be decreased by employing a fast-acquisition phase-locked loop that is switched out after acquisition in favor of a low phase-noise phase-locked loop. Another example can reduce phase noise by employing a YIG oscillator. To improve acquisition time, a first, faster phase-locked loop can be used to lock to a signal before switching to a second, slower phase-locked loop that includes the YIG oscillator. Another example can provide low noise by including phase-locked loops that operate in a frequency range having low thermal noise while a frequency of an output signal varies over a wide range.

A touch detection method, a touch detection circuit, a touch chip and an electronic device. The touch detection method includes: receiving a real-time synchronization signal sent by a touch display panel; acquiring a frequency of a noise signal in a working environment of a touch chip; setting a frequency of a coding drive signal based on the frequency of the noise signal, generating the coding drive signal based on the frequency of the coding drive signal, and outputting the coding drive signal to a drive electrode of the touch display panel; generating a strobe signal based on the real-time synchronization signal; and receiving a signal of a sensing electrode of the touch display panel, and outputting a detection result based on the strobe signal and the signal of the sensing electrode.

Disclosed is a frequency multiplication apparatus including a first frequency multiplier receiving a first signal having a first frequency and outputting a second signal having a second frequency by multiplying the first frequency by ‘n’ (‘n’ being a positive integer), a second frequency multiplier receiving the second signal and outputting a third signal having a third frequency by multiplying the second frequency by ‘m’ (‘m’ being a positive integer), and a coupler connected between an output of the first frequency multiplier and an input of the second frequency multiplier and outputting a part of the second signal.

A touch detection method, a touch detection circuit, a touch chip and an electronic device. The touch detection method includes: receiving a real-time synchronization signal sent by a touch display panel; acquiring a frequency of a noise signal in a working environment of a touch chip; setting a frequency of a coding drive signal based on the frequency of the noise signal, generating the coding drive signal based on the frequency of the coding drive signal, and outputting the coding drive signal to a drive electrode of the touch display panel; generating a strobe signal based on the real-time synchronization signal; and receiving a signal of a sensing electrode of the touch display panel, and outputting a detection result based on the strobe signal and the signal of the sensing electrode.

Frequency synthesizers having reduced phase noise and a small step size. One example can provide frequency synthesizers having low phase noise by eliminating dividers in a feedback path and instead employing frequency converters, such as mixers. Step size can be further reduced by providing frequency converters in a reference signal feedforward path. Acquisition time can be decreased by employing a fast-acquisition phase-locked loop that is switched out after acquisition in favor of a low phase-noise phase-locked loop. Another example can reduce phase noise by employing a YIG oscillator. To improve acquisition time, a first, faster phase-locked loop can be used to lock to a signal before switching to a second, slower phase-locked loop that includes the YIG oscillator. Another example can provide low noise by including phase-locked loops that operate in a frequency range having low thermal noise while a frequency of an output signal varies over a wide range.

Disclosed is a frequency multiplication apparatus including a first frequency multiplier receiving a first signal having a first frequency and outputting a second signal having a second frequency by multiplying the first frequency by n (n being a positive integer), a second frequency multiplier receiving the second signal and outputting a third signal having a third frequency by multiplying the second frequency by m (m being a positive integer), and a coupler connected between an output of the first frequency multiplier and an input of the second frequency multiplier and outputting a part of the second signal.

A system, circuit and method for providing a controlled oscillator frequency with reduced phase noise for use in a communication system. In one embodiment, the circuit includes a delay line coupled to an output of a voltage controlled oscillator (VCO). The circuit also includes a combiner having a first input coupled to an output of the delay line, and a second input coupled to the output of the VCO. An output of the combiner is coupled to a control input of the VCO.

A novel voltage controlled oscillator (VCO) based on complementary current-injection field-effect transistor (CiFET) devices is disclosed. The VCO includes an odd number stages of rings, each of rings comprises a CiFET.

A signal generator. A voltage controlled oscillator generates a signal that is fed to a comb generator, e.g., a nonlinear transmission line. A tone, from among a comb of tones at the output of the comb generator, is selected by a bandpass filter, its frequency is divided, e.g., by a direct digital synthesizer, and the result is compared, e.g., by a phase and frequency detector that receives a reference signal at its other input. The output of the phase and frequency detector is fed back, e.g., through a lowpass filter, to the voltage controlled oscillator.