A circuit includes a random oscillation number generator (RONG) configured to generate first and second pulse signals at first and second RONG outputs. A first counter is coupled to the first RONG output and generates a first count at a first counter output. A second counter is coupled to the second RONG output and generates a second count at a second counter output. A selection circuit is coupled to the first and second counter outputs and to the first and second RONG outputs. A first pulse shaper is connected between the first RONG output and the first counter, and a second pulse shaper is connected between the second RONG output and the second counter.

A lock detector (8) detects an unlocked state from an output of a phase frequency comparator (1). A counter (9) counts a reference signal, in a case where an unlocked state is detected by the lock detector (8). A parameter controlling circuit (10) acquires the count value of the counter (9), and controls switching on and off of a switch (12) for a D/A converter (11) that generates a signal to be added to an output of a loop filter (3), and the output voltage of the D/A converter (11) so that the count value of the counter (9) falls within a set value.

A circuit for providing a fractional divider/multiplier using harmonic recombination may include a power amplifier, an oscillator coupled to the power amplifier, and a divider coupled to the oscillator. In one or more implementations, the divider is configured to generate one or more phases of a harmonic from the oscillator to reduce signal interference from the power amplifier. In one or more implementations, the divider includes a divide-by-M divider, where M is a positive integer, and an array of transconductance cells coupled to the output of the divide-by-M divider. In one or more implementations, the divider includes an inductor or a filter coupled to the output of the array of transconductance cells. In one or more implementations, the oscillator includes a logical gate and a resistor-capacitor circuit coupled in series feedback with a multi-stage ring oscillator. The oscillator may include a divider coupled to the multi-stage ring oscillator.

A circuit for providing a fractional divider/multiplier using harmonic recombination may include a power amplifier, an oscillator coupled to the power amplifier, and a divider coupled to the oscillator. In one or more implementations, the divider is configured to generate one or more phases of a harmonic from the oscillator to reduce signal interference from the power amplifier. In one or more implementations, the divider includes a divide-by-M divider, where M is a positive integer, and an array of transconductance cells coupled to the output of the divide-by-M divider. In one or more implementations, the divider includes an inductor or a filter coupled to the output of the array of transconductance cells. In one or more implementations, the oscillator includes a logical gate and a resistor-capacitor circuit coupled in series feedback with a multi-stage ring oscillator. The oscillator may include a divider coupled to the multi-stage ring oscillator.

A pleat counter and methods are provided to accurately count the number of pleats in a corrugated sheet of material to be used for the production of air filters. The pleat counter comprises a pleat detector mounted underneath a mounting board for counting the pleats. The mounting board is configured to position the pleat detector adjacent to the corrugated sheet of filter material. The pleat detector includes one or more sensors configured to detect the presence of individual pleats comprising the corrugated sheet. The pleat counter includes an interface configured to enable coupling the pleat counter with a data processing system. The data processing system may comprise any of a desktop, a tablet, a server, a mobile phone, a media player, a personal digital assistant (PDA), a personal communicator, a network router or hub, a wireless access point (AP) or repeater, a set-top box, or a combination thereof.

A pleat counter and methods are provided to accurately count the number of pleats in a corrugated sheet of material to be used for the production of air filters. The pleat counter comprises a pleat detector mounted underneath a mounting board for counting the pleats. The mounting board is configured to position the pleat detector adjacent to the corrugated sheet of filter material. The pleat detector includes one or more sensors configured to detect the presence of individual pleats comprising the corrugated sheet. The pleat counter includes an interface configured to enable coupling the pleat counter with a data processing system. The data processing system may comprise any of a desktop, a tablet, a server, a mobile phone, a media player, a personal digital assistant (PDA), a personal communicator, a network router or hub, a wireless access point (AP) or repeater, a set-top box, or a combination thereof.

Disclosed examples include non-volatile counter systems to generate and store a counter value according to a sensor pulse signal, and power circuits to generate first and second supply voltage signals to power first and second power domain circuits using power from the sensor pulse signal, including a switch connected between first and second power domain supply nodes, a boost circuit, and a control circuit to selectively cause the switch to disconnect the first and second power domain circuits from one another after the first supply voltage signal rises above a threshold voltage in a given pulse of the sensor pulse signal, and to cause the boost circuit to boost the second supply voltage signal after the regulator output is disconnected from the second power domain supply node in the given pulse.

A pulse generation circuit has: an edge detector detecting a pulse edge in an input signal to generate edge detection signals; a clock generator generating a clock signal according to the edge detection signals; a frequency divider dividing the frequency of the clock signal to generate a frequency-divided clock signal; an input pad for receiving a test mode switch signal from a tester; and an output pad for outputting the frequency-divided clock signal to the tester. The edge detector can generate the edge detection signals by detecting a pulse edge not in the input signal but in the clock signal or in the inverted clock signal obtained by inverting the logic level of the clock signal when the test mode switch signal is being fed in. The signal delay time in the edge detector is adjustable according to the period of the frequency-divided clock signal as measured by the tester.

A pulse generation circuit has: an edge detector detecting a pulse edge in an input signal to generate edge detection signals; a clock generator generating a clock signal according to the edge detection signals; a frequency divider dividing the frequency of the clock signal to generate a frequency-divided clock signal; an input pad for receiving a test mode switch signal from a tester; and an output pad for outputting the frequency-divided clock signal to the tester. The edge detector can generate the edge detection signals by detecting a pulse edge not in the input signal but in the clock signal or in the inverted clock signal obtained by inverting the logic level of the clock signal when the test mode switch signal is being fed in. The signal delay time in the edge detector is adjustable according to the period of the frequency-divided clock signal as measured by the tester.

A frequency divider is provided that includes a plurality of latches for dividing an input clock according to an integer frequency divisor N of three or greater. Each latch is coupled to a corresponding pair of logic gates. For each latch, one of the logic gates in the corresponding pair controls a setting of the latch whereas a remaining one of the logic gates in the corresponding pair controls a resetting of the latch. Each latch outputs a pair of overlapping clock signals that are divided in frequency with respect to the input clock and have a 50% duty cycle. Each logic gate processes a pair of the overlapping clock signal and the input clock signal to provide a non-overlapping clock signal of the same frequency of the overlapping clock signals but have a (50/N) % duty cycle.