A method for performing divided-clock phase synchronization in a multi-divided-clock system, an associated synchronization control circuit, an associated synchronization control sub-circuit and an associated electronic device are provided. The method may include: performing frequency division operations according to a source clock to generate a first divided clock and a second divided clock; performing phase relationship detection on the first divided clock according to the second divided clock to generate a phase relationship detection result signal; performing a logic operation on a first phase selection result output signal and the phase relationship detection result signal to generate a second phase selection result output signal; and outputting one of the second divided clock and an inverted signal of the second divided clock according to the second phase selection result output signal, for further use in a physical layer circuit.

A circuit includes a clock generator, a frequency divider, and a first biasing circuit. The clock generator generates a clock signal of a first frequency. The frequency divider includes a first pair of cross coupled transistors. The frequency divider produces the clock signal of a second frequency. The first biasing circuit is coupled with the first pair of cross coupled transistors of the frequency divider. The first biasing circuit is adapted to enable a change in a transconductance of the first pair of cross coupled transistors to stabilize a phase angle between the clock signal at the first frequency and the clock signal at the second frequency.

A buffer circuit, a frequency dividing circuit, and a communications device are disclosed. The buffer circuit includes a buffer, a first control circuit, and a second control circuit. The buffer is coupled to a frequency divider, and the buffer is configured to receive a first signal output by the frequency divider, and output a fourth signal by using an output terminal of the buffer circuit when driven by the first signal, where the first signal is obtained by the frequency divider by performing frequency division on a group of differential signals, and the differential signals include a second signal and a third signal. The first control circuit is configured to perform delay control on a rising edge of the fourth signal based on the second signal. The second control circuit is configured to perform delay control on a falling edge of the fourth signal based on the third signal.

A buffer circuit, a frequency dividing circuit, and a communications device are disclosed. The buffer circuit includes a buffer, a first control circuit, and a second control circuit. The buffer is coupled to a frequency divider, and the buffer is configured to receive a first signal output by the frequency divider, and output a fourth signal by using an output terminal of the buffer circuit when driven by the first signal, where the first signal is obtained by the frequency divider by performing frequency division on a group of differential signals, and the differential signals include a second signal and a third signal. The first control circuit is configured to perform delay control on a rising edge of the fourth signal based on the second signal. The second control circuit is configured to perform delay control on a falling edge of the fourth signal based on the third signal.

A capacitive digital isolator circuit includes: a signal emitting module; a signal receiving module; and a capacitive isolation module. The signal emitting module includes an edge Pulse-Coding modulator circuit, which modulates an input signal to generate a pair of differential modulated signals based on the input signal and transmits the pair of differential modulated signals to the signal receiving module. Each of the pair of differential modulated signals has twelve high-frequency pulses when the input signal has a rising edge and has six high-frequency pulses when the input signal has a falling edge. The signal receiving module includes an ultra-low power consumption high-speed comparator, a timer and a pulse counter. An output signal of the pulse counter has a rising edge when the pulse number of the comparator output signal is larger than nine and a falling edge when the pulse number is equal to or smaller than nine.

A frequency divider circuit includes: a first latch circuit that including: a pair of input transistors each having a gate thereof configured to connect to a signal line to which a first voltage is supplied; and a pair of output nodes, and configured to receive a single-phase clock signal; and a second latch circuit of SR-type, the second latch circuit having a set input thereof and a reset input thereof configured to connect to the pair of output nodes of the first latch circuit, and configured to output differential clock signals of which frequency is half a frequency of the single-phase clock signal. The first latch circuit is configured to perform amplification and reset operations alternately repeatedly in response to the single-phase clock signal.

A capacitive digital isolator circuit includes: a signal emitting module; a signal receiving module; and a capacitive isolation module. The signal emitting module includes an edge Pulse-Coding modulator circuit, which modulates an input signal to generate a pair of differential modulated signals based on the input signal and transmits the pair of differential modulated signals to the signal receiving module. Each of the pair of differential modulated signals has twelve high-frequency pulses when the input signal has a rising edge and has six high-frequency pulses when the input signal has a falling edge. The signal receiving module includes an ultra-low power consumption high-speed comparator, a timer and a pulse counter. An output signal of the pulse counter has a rising edge when the pulse number of the comparator output signal is larger than nine and a falling edge when the pulse number is equal to or smaller than nine.

A fractional divider is described herein which effectively performs an integer division followed by phase shifting, pulse swallowing, and/or multiplexing to realize a fractional divisor. The fractional divider divides an input clocking signal by a first integer divisor in a first mode of operation or by a second integer divisor in a second mode of operation to provide a first phase of a divided digital signal. Thereafter, the fractional divider shifts the first phase of the divided digital signal to provide a second phase of the divided digital signal in the first and second modes of operation. Finally, the fractional divider synchronizes an output clocking signal to the first phase of the divided digital signal and the second phase of the divided digital signal in the first and second modes of operation.

A frequency divider circuit includes: a first latch circuit that including: a pair of input transistors each having a gate thereof configured to connect to a signal line to which a first voltage is supplied; and a pair of output nodes, and configured to receive a single-phase clock signal; and a second latch circuit of SR-type, the second latch circuit having a set input thereof and a reset input thereof configured to connect to the pair of output nodes of the first latch circuit, and configured to output differential clock signals of which frequency is half a frequency of the single-phase clock signal. The first latch circuit is configured to perform amplification and reset operations alternately repeatedly in response to the single-phase clock signal.

The present disclosure relates to a method for quadrature error correction using a frequency divider circuit. The method comprises delaying input of data to master input terminals and/or slave input terminals of the frequency divider circuit for correcting a quadrature error between the in-phase and quadrature-phase output signals.