Disclosed is a pulse elimination circuit, a voltage detection circuit and a detection method, referring to a field of electronic circuit technology. The pulse elimination circuit comprises: a clock generation circuit configured to receive a logic signal and a first input signal and generate a clock signal according to the logic signal and the first input signal; a counter coupled with the clock generation circuit and configured to receive the clock signal and count a number of cycles of the clock signal to generate a second input signal; a signal output circuit coupled to the counter and configured to supply a first input signal to the clock generation circuit and generate a pulse elimination signal based on the second input signal. Therefore, in a process of voltage detection, this circuit can eliminate a false trigger caused by short pulse and improve voltage detection accuracy.

A fractional-N divider of a frequency synthesizer is driven by a dither-less and seed-less multi-stage noise shaping (MASH) modulator to alleviate fractional spurious tones introduced by the cyclic train of division ratios from delta-sigma modulators. The MASH modulator includes at least two cascaded dither-less delta-sigma modulators where each modulator includes a first feedback loop the generates the modulator feedback signal, a second feedback loop that disrupts fractional spurious tones and a third feedback loop that provides approximately zero static error. The MASH modulator further includes a combining circuit delays at least one code sequence from at least one of the delta-sigma modulators and that combines the code sequence generated by each of the delta-sigma modulators and at least one delayed code sequence.

For example, an apparatus may include a digitally-controlled frequency multiplier, which may be controllable according to a digital control input, to generate an output frequency signal having an output frequency, for example, by multiplying an input frequency of an input frequency signal. For example, the digitally-controlled frequency multiplier may include a phase generator configured to generate a plurality of phase-shifted signal groups corresponding to a respective plurality of first phase-shifts applied to the input frequency signal, a plurality of digital clock multipliers controllable according to the digital control input to generate a respective plurality of frequency-multiplied signals based on the plurality of phase-shifted signal groups, and a combiner to generate the output frequency signal based on a combination of the plurality of frequency-multiplied signals.