An LO clock signal generator includes a fundamental mixer for mixing a source clock signal with a divided version of the source clock signal. The LO clock signal generator also includes a harmonic mixer for mixing the source clock signal with a third harmonic of a divided version of the source clock signal.

An apparatus includes a plurality of latches and a plurality of logic gates. Each latch may be setable and resettable. The logic gates may be connected to the latches to form a multi-modulus divider that generates an output clock signal by dividing an input clock signal in response to a command signal. Each latch may be commanded into a corresponding initial state while the command signal is in an initialization state. Each latch is generally free to change states while the command signal is in a run state. A modulus division operation of the multi-modulus divider may start upon an initial edge of the input clock signal after the command signal changes from the initialization state to the run state.

A method for dithering a fractional clock divider includes generating a first clock enable sequence based on a seed pattern of M ones and N minus M zeros, selecting a cyclic rotation of the seed pattern after N input clock cycles, and generating a second clock enable sequence based on the cyclic rotation. A clock gate receives the input clock signal and the clock enable sequences and outputs M clock cycles for every N input clock cycles. A random number generator indicates the cyclic rotation of the seed pattern. The seed pattern can be replaced with an updated seed pattern of M ones and N minus M zeros in a different order. In some examples, the clock enable sequence is generated using a cyclic shift register containing the seed pattern and a multiplexor. In other examples, the clock enable sequence is generated using a modulo N counter and a comparator.

Provided is a neuromorphic arithmetic device. The neuromorphic arithmetic device may include a synapse circuit, a metal line having an inherent capacitance component, an oscillator, a comparator, and a capacitance calibrator. The synapse circuit may be configured to perform a multiplication operation on a PWM signal and a weight to generate a current. The metal line may include a metal line capacitor in which a charge of the current is stored. The oscillator generates a plurality of pulses on the basis of the charge stored in the metal line capacitor. The comparator may compare a frequency of the plurality of pulses and a target frequency, and may generate a control signal on the basis of a result of the comparison. The capacitance calibrator may adjust a capacitance value of the metal line capacitor on the basis of the control signal.

A method for reducing deterministic jitter in a clock generator includes providing a load current through a regulated voltage node to a circuit responsive to a divide ratio. The method includes providing an auxiliary current through the regulated voltage node. The auxiliary current has a first current level during a first period corresponding to a first value of the divide ratio and the auxiliary current has a second current level during a second period corresponding to a second value of the divide ratio.

A semiconductor device includes a first oscillator circuit, a clock monitoring circuit and a timing signal generation circuit for periodically switching the operating mode of the clock monitoring circuit to one of the first to third modes. The clock monitoring circuit includes: a clock counter configured for counting the number of oscillations of the clock signal in the first mode and configured for shifting the pulses of the input signal to the output signal at normal time in the third mode; a comparison circuit for comparing whether the count value per predetermined period by the clock counter is within an expected value in the second mode; and an edge detection circuit for detecting whether the pulses of the input signal are shifted to the output signal of the clock counter in the third mode.

A multi-modulus frequency divider circuit includes first and second frequency division stages. The first frequency division stage receives a first input clock signal having a first oscillating frequency, a first modulus input signal, and a first division bit. The first frequency division stage divides the first oscillating frequency by a first division ratio, and generates a second input clock signal having a second oscillating frequency. The second frequency division stage receives the second input clock signal, a second modulus input signal, and a second division bit. The second frequency division stage generates an output clock signal having an output oscillating frequency by dividing the second oscillating frequency by a second division ratio.

A programmable clock divider having reset circuits configured to receive a DP count comprises a first flip-flop having a clock input, a first output, and one of the DP inputs configured to receive a clock signal, a plurality of flip-flops connected to form a ripple counter configured to each receive a DP input, a clock input, and a reset input to provide a first output coupled to the clock input of a subsequent flip-flop of the plurality of flip-flops, each subsequent flip-flop having its clock input coupled to the first output of the preceding flip-flop, a first reset circuit coupled to the flip-flops configured to provide an out signal in response to the flip-flops obtaining the DP count, and a second reset circuit configured to provide a reset signal to the reset input of the plurality of flip-flops in response to the out signal from the first reset circuit.

A method for dithering a fractional clock divider includes generating a first clock enable sequence based on a seed pattern of M ones and N minus M zeros, selecting a cyclic rotation of the seed pattern after N input clock cycles, and generating a second clock enable sequence based on the cyclic rotation. A clock gate receives the input clock signal and the clock enable sequences and outputs M clock cycles for every N input clock cycles. A random number generator indicates the cyclic rotation of the seed pattern. The seed pattern can be replaced with an updated seed pattern of M ones and N minus M zeros in a different order. In some examples, the clock enable sequence is generated using a cyclic shift register containing the seed pattern and a multiplexor. In other examples, the clock enable sequence is generated using a modulo N counter and a comparator.

A local oscillator generator (LO generator) may be configured to transmit an LO signal to a mixer. The LO generator may include an input buffer configured to generate a first internal oscillator signal based on the input oscillator signal. The LO generator may include a frequency dividing circuit configured to generate a second internal oscillator signal based on dividing a frequency of the first internal oscillator signal. The LO generator may include an output buffer configured to generate the LO signal based on the second internal oscillator signal. The input buffer and the frequency dividing circuit may each be configured to receive a power voltage independently of the output buffer.