The present disclosure discloses a multi-standard performance reconfigurable I/Q orthogonal carrier generator. The generator may implement a continuously covered I/Q carrier output of 0.1-5 GHz and continuously covered differential signal outputs of 5-10 GHz and 1.5-3 GHz by means of reasonable frequency assignment; also, carrier signals under various frequencies with different loop bandwidths, different phase noises, different power consumption levels and different locking times can be generated by configuring a programmable charge pump (102), a loop filter (103) parameter, a multi-path voltage-controlled oscillator (104) and a first multiplexer (105) corresponding thereto, a five-stage-division-by-two frequency division link (109) and a corresponding second multiplexer (110) and third multiplexer (112), so as to implement generation of a multi-standard performance reconfigurable I/Q orthogonal carrier.

A dual-PFD circuit with delay feedback generated by a dual-modulus prescaler based on mode control from a feedback delay generation circuit. The PFD circuit can be used with a PLL feedback divider to divide a VCO clock signal VCO_clk and generate FB and FB_DLY signals. The PLL feedback divider includes a dual modulus prescaler to selectively divide the VCO_clk by either M or M+1 (such as 4/5) based on a divide mode control input to generate a prescaled divide signal, and a programmed counter/divider (N counter/1/N divider) to selectively divide the prescaled divide signal to generate the FB signal, and a delay generation circuit to selectively delay the FB signal by a pre-defined delay to generate the FB_DLY signal. The prescaler is responsive to the pre-defined delay from the delay generation circuit to change divide modes. The dual PFD circuit response to the FB and FB_DLY signals in relation to a reference signal to generate a phase comparison signal. the dual-PFD circuit can be used with a charge-pump coupled to the dual PFD circuit, and responsive the phase comparison signal to generate a frequency tuning voltage, for input to a VCO for generating the VCO clock signal. The dual PFD circuit, charge pump and VCO can be used in a PLL frequency synthesizer.

A multi-modulus frequency divider includes a frequency division module, a frequency selection module, and a retiming module. The frequency division module is configured to receive an input signal and perform mufti-mode frequency processing on the input signal, so as to generate and output a plurality of divided signals to the frequency selection module. The frequency selection module is configured to receive the plurality of divided signals from the frequency division module, select a divided signal having a desired frequency from among the plurality of divided signals, and output the selected divided signal to the retiming module. The retiming module is configured to receive the selected divided signal from the frequency selection module, perform a retiming operation on the selected divided signal, and output a retimed selected divided signal.

Described herein are systems and methods that provide for asymmetric image splitter image stream applications. In one embodiment, a system supporting image multi-streaming comprises an asymmetric image splitter engine that splits super-frame image streams into two or more image streams and a fractional clock divider circuit. The fractional clock divider may comprise a digital feedback control loop and a one-bit sigma delta modulator. The fractional clock divider circuit may provide compatible display clock frequencies for each of the two or more image streams. When a multi-image stream comprises the two image streams, the asymmetric image splitter engine adjusts a vertical asymmetry of a first image stream with a shortest height to same height as a second image stream by adding vertical padding to the first image stream. The super-frame image streams may comprise image streams from video, LIDAR, radar, or other sensors.

A switching frequency controller, a voltage converter, and a method are used for controlling switching frequency. The switching frequency controller includes a frequency divider, a frequency detector, an accumulation counter, and an on-time controller. The frequency divider generates a divisional signal having a divisional frequency according to an input signal having a target frequency. The target frequency is 2.sup.N times of the divisional frequency. The frequency detector receives the divisional frequency and a switching control signal, and calculate a number of periods that pass by during each cycle of the divisional signal. The number of periods is represented by (N+1) bits. The accumulation counter increases or decreases a control indication value by a predetermined value according to a most significant bit of the number of periods. The on-time controller adjusts an on-time length of the switching control signal according to the control indication value.

A switching frequency controller, a voltage converter, and a method are used for controlling switching frequency. The switching frequency controller includes a frequency divider, a frequency detector, an accumulation counter, and an on-time controller. The frequency divider generates a divisional signal having a divisional frequency according to an input signal having a target frequency. The target frequency is 2.sup.N times of the divisional frequency. The frequency detector receives the divisional frequency and a switching control signal, and calculate a number of periods that pass by during each cycle of the divisional signal. The number of periods is represented by (N+1) bits. The accumulation counter increases or decreases a control indication value by a predetermined value according to a most significant bit of the number of periods. The on-time controller adjusts an on-time length of the switching control signal according to the control indication value.

A digital frequency synthesizer includes a delay-locked loop (DLL) that generates time-delayed versions of a reference clock signal, a clock divider that executes an integer-division operation on one delayed clock signal to generate an integer-divided clock signal, and control circuitry that generates fractional data for enabling a fractional division. The digital frequency synthesizer further includes a first clock selector that selects one delayed clock signal as a DLL clock signal based on the fractional data, a delay chain that generates time-delayed versions of the DLL clock signal, and a second clock selector that selects one delayed clock signal as a selected clock signal based on the fractional data. A rising edge of the integer-divided clock signal is adjusted based on the selected clock signal to generate a fractional-divided clock signal that is a fractional-divided version of the reference clock signal.

A digital frequency synthesizer includes a delay-locked loop (DLL) that generates time-delayed versions of a reference clock signal, a clock divider that executes an integer-division operation on one delayed clock signal to generate an integer-divided clock signal, and control circuitry that generates fractional data for enabling a fractional division. The digital frequency synthesizer further includes a first clock selector that selects one delayed clock signal as a DLL clock signal based on the fractional data, a delay chain that generates time-delayed versions of the DLL clock signal, and a second clock selector that selects one delayed clock signal as a selected clock signal based on the fractional data. A rising edge of the integer-divided clock signal is adjusted based on the selected clock signal to generate a fractional-divided clock signal that is a fractional-divided version of the reference clock signal.

A flash analog-to-digital converter (ADC) receives an input control signal and performs coarse tuning of a frequency of an output signal, produced between first and second nodes having an inductance coupled therebetween. The flash ADC quantizes an operating frequency range for the output signal produced between the first and second nodes as M.Math.f, where M is an integer from 0 to N1, where N is a number of intervals into which a frequency range for the output signal is divided, and where f is a resulting frequency step produced by the quantizing. The value of M is generated based upon the input control signal and a word controlling switches of a plurality of switched capacitance circuits associated with the first and second nodes to close ones of those switches associated with the control word to coarsely tune the frequency of the output signal.

A flash analog-to-digital converter (ADC) receives an input control signal and performs coarse tuning of a frequency of an output signal, produced between first and second nodes having an inductance coupled therebetween. The flash ADC quantizes an operating frequency range for the output signal produced between the first and second nodes as M.Math.f, where M is an integer from 0 to N1, where N is a number of intervals into which a frequency range for the output signal is divided, and where f is a resulting frequency step produced by the quantizing. The value of M is generated based upon the input control signal and a word controlling switches of a plurality of switched capacitance circuits associated with the first and second nodes to close ones of those switches associated with the control word to coarsely tune the frequency of the output signal.