Abstract: A pulse generator that can generate pulses separated by 120 degrees phase on each of three separate phase output leads for use with a 3-phase motor power driver. These output pulses can be of any desired frequency and voltage. In a particular embodiment of the invention, the phase output pulses take a logic level of 0-12 volts (12 volts peak) with an adjustable frequency of around 250 Hz and a duty cycle of around 50%. This combination of parameters is ideal for driving a 3-phase motor in a vehicle application. Any combination of pulse width or duty cycle, output level and frequency is within the scope of the present invention.

Abstract: In one or more embodiments, a programmable clock divider (PCD) can receive an input clock signal and a programmable number, and the PCD can produce a divided clock signal based on the programmable number. First and second circuits can compare first and second numbers, respectively, with a count value from a counter to generate first and second signals, respectively. A multiplexer can receive the first and second signals at inputs and can receive the clock signal at a selection input. The multiplexer can output an output signal, as a divided clock signal, based on the clock signal, the first signal, and the second signal, where the output signal transitions from a first value to a second value on at least one of a first edge of the first clock signal to output the first signal and a second edge of the first clock signal to output the second signal.

Abstract: A frequency synthesizer is provided, including a voltage-controlled oscillator (VCO), a frequency prescaler, a divide-by-2.5 circuit, and a selector. The VCO determine the frequency of a first signal according to an input voltage. The frequency prescaler determines the frequency of a second signal to be the frequency of the first signal divided by 3, 3.5, or 4 according to a first selection signal, and the frequency prescaler also determines the frequency of a third signal to be the frequency of the first signal divided by 6, 7, or 8 according to the first selection signal. The divide-by-2.5 circuit generates a fourth signal, wherein the frequency of the fourth signal is the frequency of the first signal divided by 2.5. The selector selects one of the second signal, the third signal, and the fourth signal as a fifth signal according to a second selection signal.

Abstract: There is provided a system for comparing the phase characteristics of three generated clock signals, each having a unique phase relationship with an original clock signal, with the original clock signal and to select a signal based on the proximity of the phase characteristic of the three signals to the original signal. The selection of a clock signal that most closely approximates the original significantly reduces lock time when attempting to synchronize an internal clock with an external clock. Additionally, there is provided a method for comparing three clock signals with an original clock signal and selecting from the three clock signals one that is approximately in phase with the original clock signal.

Abstract: A frequency divider reduces jitter and power consumption, and includes a phase selector for receiving a plurality of clock signals and outputting an intermediate signal corresponding to phase characteristic of at least one of the clock signals, and an adjustable delay circuit for receiving the intermediate signal and generating an output signal by delaying the received intermediate signal.

Abstract: Embodiments of apparatuses, articles, methods, and systems for a synthesizer with an extended multi-modulus prescaler are generally described herein. Described embodiments include an offset controller that provides an offset to a first counter value and a multi-modulus prescaler to implement a first modulated division number based on the first counter value and a second counter value. The offset controller may compensate for the offset to provide a second modulated division number based on the first modulated division number. Other embodiments may be described and claimed.

Abstract: A clock generator is illustrated. The clock generator mentioned above includes a multimodulus frequency divider and a delta-sigma modulator. The multimodulus frequency divider is archived by switching the phase thereof. The multimodulus frequency divider increases the operating frequency of the clock generator effectively, and has a characteristic with half period resolution for reducing the jitter of an output clock signal when its spectrum is spread. Besides, the delta-sigma modulator increases the accuracy of the triangle modulation and reduces error of quantization by adding a few components therein. Thus, the clock generator could be expanded to a programmable clock generator.

Abstract: In a frequency dividing device, a 1/P frequency divider subjects an input clock signal to 1/P frequency division. A phase shifter shifts the phase of the 1/P frequency signal and outputs multiple different Q-phase signals. A switch controls phase shifting in accordance with a division ratio control signal, to switch the Q-phase signals from one to another. A 1/R frequency divider subjects the output from the switch to 1/R frequency division and outputs an Rth frequency clock signal. A ½ frequency divider subjects the Rth frequency clock signal to ½ frequency division and outputs a frequency divided clock signal. A division ratio setter receives a division ratio set signal and generates the division ratio control signal. As a division ratio, P×R×2?2×P/Q, P×R×2?P/Q, P×R×2, P×R×2+P/Q, and P×R×2+2×P/Q can be set.

Abstract: Systems and methods for providing a clock signal are provided. A frequency multiplier circuit is provided that can include a plurality of serially connected delay elements that are configured to generate a plurality of delay tap signals from an input signal. The frequency multiplier circuit can also include a phase detector configured to receive a first selected delay tap signal and the input signal. The phase detector can detect a phase shift between the first selected delay tap signal and the input signal, and can generate a phase detection signal indicative of a value of the phase shift. The frequency multiplier circuit can also include a digital logic gate configured to receive the input signal and a second selected delay tap signal. The digital logic gate can be further configured to generate an output signal responsive to the second selected delay tap signal and the input signal. The frequency multiplier circuit can also include a controller coupled to the phase detector and coupled to an output gate.

Abstract: A frequency divider circuit includes a master-slave flip-flop having a master flip-flop and a slave flip-flop. The slave flip-flop is connected to the master flip-flop. The master flip-flop includes a first plurality of logic gates and is configured to receive a first clock signal. The slave flip-flop includes a second plurality of logic gates and is configured to receive a second clock signal. The second plurality of logic gates is implemented using single-ended diode-transistor logic (DTL).

Abstract: A multi-phase signals generator is disclosed. The multi-phase signals generator mentioned above includes a frequency divider and N delay circuits. The frequency divider receives a clock signal and divides a frequency of the clock signal to generate a divided frequency clock signal. The N delay circuits are connected in series. The delay circuit connected in a first stage receives the divided frequency clock signal. The delay circuit connected in an ith stage receives an output of the delay circuit connected in an (i?1)th stage, wherein i is an integer larger than 2. The delay circuits respectively delay a received signal according to the clock signal and generate N delay output signals, wherein N is an integer larger than 3. Moreover, a plurality of times for transmitting the clock signal to all of the delay circuits are the same.

Abstract: A clock generator is illustrated. The clock generator mentioned above includes a multimodulus frequency divider and a delta-sigma modulator. The multimodulus frequency divider is archived by switching the phase thereof. The multimodulus frequency divider increases the operating frequency of the clock generator effectively, and has a characteristic with half period resolution for reducing the jitter of an output clock signal when its spectrum is spread. Besides, the delta-sigma modulator increases the accuracy of the triangle modulation and reduces error of quantization by adding a few components therein. Thus, the clock generator could be expanded to a programmable clock generator.

Abstract: A multi-modulus divider (MMD) receives an MMD input signal and outputs an MMD output signal SOUT. The MMD includes a chain of modulus divider stages (MDSs). Each MDS receives an input signal, divides it by either two or three, and outputs the result as an output signal. Each MDS responds to its own modulus control signal that controls whether it divides by two or three. In one example, a sequential logic element outputs SOUT. The low jitter modulus control signal of one of the first MDS stages of the chain is used to place a sequential logic element into a first state. The output signal of one of the MDS stages in the middle of the chain is used to place the sequential logic element into a second state. Power consumption is low because the sequential logic element is not clocked at the high frequency of the MMD input signal.

Abstract: A clock frequency divider for odd numbered divide ratios. The divider clocks two counters in parallel from a reference clock to be divided. One counter is loaded with the divide ratio and the other counter is loaded with the divide ratio except for the least significant bit. The second counter will set a latch when its count has elapsed. The first counter will reset the latch when its count has elapsed and will reload the counters. The latch is used for the divided output, but passes through a retiming circuit. The retiming circuit delays the output edge by one reference clock edge when the least significant bit indicates an odd numbered divide ratio.

Abstract: In one embodiment of the present invention, a clock generator circuit receives a clock signal having a period. The clock signal is employed by a digital circuit that is resident on the same substrate as an analog circuit, the digital circuit generates disturbance climaxes at clock edges that propagate through the substrate to the analog circuit. A clock generator circuit generates a plurality of clock signals, with each clock signal having a unique rate, wherein during a temporal gap, defined by the time between a last disturbance climax and a next sampling time of the clock signal, clock edges of any of the plurality of clock signals are avoided.

Abstract: A programmable divider apparatus comprises a first divider, a second divider, a feedback control unit, and a plurality of control signals. The first divider provides a frequency division operation of division by at least three integers, the second divider is cascaded to the first divider to provide a frequency division operation of division by two integers. The feedback control unit is coupled to between the first divider and the second divider to provide a feedback control signal to selectively supply an output of the second divider to an input of the first divider. The apparatus control signals and the feedback control signal are used to execute the first divider or the second divider.

Abstract: A phase locked loop frequency synthesizer with jitter compensation having a tapped delay line for compensating the jitter prior to passing a signal subject to jitter through a non-linearity; and, a ?? modulator for generating, or a storing element for pre-generated storing, of a fractional pattern representing fractional weighting of a plurality of integer divisors, wherein the fractional pattern identifies one integer divisor, out of the plurality of integer divisors, at a time to be active.

Abstract: A counter/divider where the counter/divider comprises a: a pre-scaler operable in a first mode to divide an input signal by M and in a second mode to divide the input signal by N, where N is greater than M; a first programmable counter, and a second programmable counter; and where the first and second programmable counters are responsive to an output of the pre-scaler and an output of the first counter controls whether the pre-scaler operates in the first mode or the second mode, wherein the first counter is operable to count to greater than one.

Abstract: A multimode millimeter-wave frequency divider circuit with multiple selectable frequency dividing modes is proposed, which is designed for integration with a millimeter wave (MMW) circuit system, such as a phase-locked loop (PLL) circuit, for providing multimode frequency dividing functions. In actual application, the millimeter wave frequency divider circuit of multi frequency dividing mode provides at least three frequency dividing operational modes, including modes of dividing two, dividing 3 and dividing four. In practice, the millimeter wave frequency divider circuit of multi frequency divider mode may be integrated with a millimeter wave phase-locked circuit to provide a frequency synthetic function having multi frequency sections, such as including 38 GHZ, 60 GHZ and 77 GHZ, and may use reduced circuit layout surfaces and operational power.

Abstract: In one embodiment, the present invention includes a frequency divider circuit for dividing the frequency of an input signal by an odd value. In one embodiment, a frequency divider circuit includes a counter configured to receive a clock input signal and a divisor having an odd value. The counter counts clock cycles up to the divisor to generate a count. A control circuit is configured to receive the count, the divisor, and the clock input signal and generate one or more control signals to control a state of a clock output signal. A half cycle adjust circuit is configured to receive the clock input signal and the one or more control signals from the control circuit and provide an additional one-half cycle adjustment of the clock output signal. The frequency divider circuit may be a feed forward circuit with fast startup characteristics.

Abstract: A frequency multiplier is disclosed. A plurality of voltage regulators each regulate levels of voltages at first and second common nodes in response to a corresponding one of input signals from a voltage-controlled delay line. An input buffer charges the first node or discharges the second node in response to a feedback signal. An output buffer regulates a level of a voltage at an output node and outputs a frequency-multiplied clock signal and the feedback signal corresponding to the voltage level of the output node. A discharge circuit discharges the first node before a rising edge of each of the input signals from the voltage-controlled delay line is inputted. A charge circuit charges the second node before the rising edge of each of the input signals from the voltage-controlled delay line is inputted.

Abstract: A local oscillator includes a programmable frequency divider coupled to the output of a VCO. The frequency divider can be set to frequency divide by three. Regardless of the divisor, the frequency divider outputs quadrature signals (I, Q) that differ from each other in phase by ninety degrees. To divide by three, the frequency divider includes a divide-by-three frequency divider. The divide-by-three frequency divider includes a divide-by-three circuit, a delay circuit, and a feedback circuit. The divide-by-three circuit frequency divides a signal from the VCO and generates therefrom three signals C, A? and B that differ from each other in phase by one hundred twenty degrees. The delay circuit delays signal A? to generate a delayed version A of the signal A?. The feedback circuit controls the delay circuit such that the delayed version A (I) is ninety degrees out of phase with respect to the signal C (Q).

Abstract: Disclosed is a frequency divider including first to fifth FFs(flip-flops), each of which receives a common clock signal and samples and outputs an input signal responsive to an effective edge of the clock, an output signal of the 1st FF being supplied to the 2nd FF, a first logic gate which receives an output signal of the 2nd FF and a first control signal and outputs the output signal of the 2nd FF, when the first control signal is of a first value, and outputs a predetermined value, when the first control signal is of a second value, the output signal of the first logic gate being supplied to an input of the 3rd FF; a second logic gate which receives an output signal of the 1st FF and a second control signal and outputs an output signal of the 1st FF, when the second control signal is of the first value and outputs the predetermined value, when the second control signal is of the second value, the output signal of the second logic gate being supplied to the 4th FF; and a third logic gate which receives an o

Abstract: A mixer includes first and second differential input pairs that include first and second transistors. First and second bias transistors receive a first signal of a differential input signal that is the one of a first phase and a second phase, and that respectively communicate with first terminals of the first and second transistors of the first differential input pair. Third and fourth bias transistors receive a second signal of the differential input signal, and that respectively communicate with first terminals of the first and second transistors of the second differential input pair. First and second capacitive elements have first and second ends that respectively communicate with the first terminals of the first and second transistors of the first and second differential input pairs. Four current sourcing elements respectively communicate with first terminals of the first, second, third, and fourth bias transistors.

Abstract: A system and method are provided for jitter-free fractional division. The method accepts a first plurality of first signal phases, each phase having a first frequency. To make the division jitter-free, a phase is selected subsequent to deselecting a previous phase selection. The selected phase is divided by the integer N, supplying a second signal with a second frequency. Using the second signal as a clock, a first plurality of counts is triggered in series, and the counts are used to select a corresponding phase. The first signal may separate neighboring phases by 90 degrees. Then, for (N+0.25), a first count triggers a second count and selects the first phase, the second count triggers a third count and selects the second phase, the third count triggers a fourth count and selects the third phase, and the fourth count trigger the first count and selects the fourth phase.

Abstract: A frequency divider includes a transmission gate, a first inverter, a first switch circuit, a second switch circuit, and a second inverter. The transmission gate transmits a clock signal according to an inverted enable signal. The first inverter inverts the clock signal outputted from the transmission gate. The first switch circuit generates a first control signal according to the inverted clock signal and an output signal of the frequency divider. The second switch circuit generates a second control signal according to the clock signal, the inverted clock signal, and the first control signal. The second inverter inverts the second control signal to generate the output signal. The frequency of the clock signal is a multiple of the frequency of the output signal.

Abstract: An embodiment of this invention combines feed-forward and feedback frequency division circuits in a such a way, to provide greater flexibility in choosing the non-integer division ratios at the output, with little added complexity. Alternate embodiments include additional divider(s) in signal or feedback paths providing additional flexibility and design simplification. An embodiment uses in-phase/quadrature signals to select the desired modes at feedback-path and signal-path mixers. Various alternatives are also described.

Abstract: This disclosure can provide methods, apparatus, and systems for dividing an input clock or master clock by an integer or non-integer divisor and generating one or more balanced, i.e., 50% duty cycle, divided that are phase-aligned to the input clock. The non-integer divisors can include half-integers, N/2, e.g. the division can be denoted 2:N. The value of N for each phase-aligned, balanced, divided clock can be distinct. The method can include generating an input clock signal having an input clock frequency, generating a secondary clock signal that transitions between a first state and a second state based on the input clock signal, generating a delayed secondary clock signal that is time delayed relative to the secondary clock signal, and generating the output clock signal that has a frequency that is a non-integer division of the input clock frequency.

Abstract: Over the years, ring counter and prescalers have been used in a variety of microelectronic applications, including Phased Locked Loops or PLLs. All of these applications have experienced both decreases in size and increases in speed. As a result, current-mode logic or CML has come into use in some high speed applications, calling for alternative designs for components such as prescalers. Here, a divide-by-three prescaler is described that uses internal states from mater-slave flip-flop pairs and that is well-suited for microelectronics that employ CML.

Abstract: Embodiments described herein are related to a counter. In some embodiments, the counter can be used as a divider, e.g., in a fractional PLL. In some embodiments, the counter (e.g., the main counter or counter C) includes a first counter (e.g., counter C1) and a second counter (e.g., counter C2), which, together with the first counter C1, perform the counting function for counter C. For example, if counter C is to count to the value N, then counter C1 counts, e.g., to N1, and counter C2 counts to N2 where N=N1+N2. For counter C1 to count to N1, N1 is loaded to counter C1. Similarly, for counter C2 to count to N2, N2 is loaded to counter C2. While counter C1 counts (e.g., to N1), N2 can be loaded to counter C2. After counter C1 finishes counting to N1, N2, if loaded, is available for counter C2 to start counting to this N2. Counters C1 and C2 can alternately count and thus provide continuous counting for counter C. Other embodiments and exemplary applications are also disclosed.

Abstract: A method for dividing a frequency includes the steps of receiving a first signal having a first frequency as a clock input to a first digital counter and outputting a second signal as a clock input to a second digital counter having a higher counting capacity than the first counter. The output occurs when the first counter reaches a first number of count cycles. The method also includes generating a third signal having a high cycle and a low cycle, which are determined at least as a function of the first number of count cycles. Depending on a desired division ratio, the high and low cycles may also be a function of a second number of count cycles associated with the second counter. The third signal has a frequency lower than the first frequency.

Abstract: The present invention provides for a self-correcting state circuit. A first flip flop is configured to receive a clock input and a first data input, and to generate a first output in response to the clock input and the first data input. A second flip flop is coupled to the first flip flop and configured to receive the clock input and to receive the first output as a second data input, and to generate a second output in response to the clock input and the first output. A first correction circuit is coupled to the second flip flop and configured to generate a corrected output. A third flip flop is coupled to the first correction circuit and configured to receive the clock input and to receive the corrected output as a third data input, and to generate a third output in response to the clock input and the third data input.

Abstract: A frequency multiplier is provided that includes a switching component having a plurality of differential pairs of transistors. The frequency multiplier further includes a gain stage. A common mode feedback generated by the switching component is also provided to the gain stage.

Abstract: A multi-modulus divider and a method for performing frequency dividing by utilizing a multi-modulus divider are disclosed. The multi-modulus divider comprises a multi-modulus dividing circuit, a pulse generating circuit, and a modulus signal generating circuit. The multi-modulus dividing circuit comprises several serially connected divider cells, of which a predetermined one may be bypassed. The multi-modulus dividing circuit generates an output frequency according to an input frequency and a divisor. A range of the divisor comprises a plurality of numerical intervals. The pulse generating circuit generates a pulse signal. The modulus signal generating circuit generates a determination result by determining which numerical interval the divisor belongs to, and inputs, according to the determination result, the pulse signal into the predetermined divider cell to be one of references which the predetermined divider cell refers to when outputting a modulus signal.

Abstract: Digital divider for low voltage LOGEN. LOGEN is a local oscillator generator. One implementation presented herein provides for a pseudo-complementary metal-oxide-semiconductor (CMOS), in that, it is not a true CMOS type circuitry that has no DC current dissipation, but nevertheless does operate well at relatively high frequencies and relatively low power supply voltage levels. Appropriately placed p-channel metal oxide semiconductor field-effect transistors (P-MOSFETs) and n-channel MOSFETs (e.g., N-MOSFETs) are employed to provide for an all digital divider circuitry. In some embodiments, four active circuitry element levels are stacked between a power supply voltage and ground voltage level. In other embodiments, three active circuitry element levels are stacked between a power supply voltage and ground voltage level. The three active circuitry element levels embodiment provides for a greater area savings (e.g.

Abstract: A device for modifying an input signal having an input signal frequency and a duty cycle is disclosed. The device determines two separate counts for each of the high and low pulses of the input signal. One of the two counts for each of the high and low pulses is divided. The divided count is then compared with the undivided count. Based on this comparison, an output module outputs an output signal that has the same duty cycle as the input signal but at a frequency that is a multiple of the input signal frequency.

Abstract: A clock frequency divider for odd numbered divide ratios. The divider clocks two counters in parallel from a reference clock to be divided. One counter is loaded with the divide ratio and the other counter is loaded with the divide ratio except for the least significant bit. The second counter will set a latch when its count has elapsed. The first counter will reset the latch when its count has elapsed and will reload the counters. The latch is used for the divided output, but passes through a retiming circuit. The retiming circuit delays the output edge by one reference clock edge when the least significant bit indicates an odd numbered divide ratio.

Abstract: A digital frequency divider including a parallel output register, a presettable asynchronous counter and a decoder. The parallel output register contains a desired count value. The presettable asynchronous counter has its preset data inputs coupled to the output of the parallel output register. The decoder receives its input from the data outputs of the presettable asynchronous divider and its output coupled to the load input of the presettable asynchronous counter.

Abstract: The dual-modulus prescaler circuit (1) is devised to operate at a very high frequency. This circuit includes an assembly formed of two dynamic D-type flip flops (12, 13), and two NAND logic gates (15, 16) arranged in negative feedback between the two flip flops. The two flip flops are clocked by an input clock signal (CK) to supply a divided output signal (OUT) whose frequency matches the input clock frequency divided by 2 or by 3 as a function of a division mode selection signal (divb) applied to the input of the first NAND logic gate (15). One non-inverted output of the second flip flop is connected to one input of the first flip flop (12). The first dynamic flip flop includes three active branches and supplies a single inverted output signal. A third flip flop (14) with three active branches receives an inverted mode selection signal (div) at input in order to supply the mode selection signal to the inverted output thereof, clocked by the non-inverted output signal of the second flip flop.

Abstract: Over the years, ring counter and prescalers have been used in a variety of microelectronic applications, including Phased Locked Loops or PLLs. All of these applications have experienced both decreases in size and increases in speed. As a result, current-mode logic or CML has come into use in some high speed applications, calling for alternative designs for components such as prescalers. Here, a divide-by-three prescaler is described that uses internal states from mater-slave flip-flop pairs and that is well-suited for microelectronics that employ CML.

Abstract: A multi-bit counter is provided. The multi-bit counter includes a plurality of asynchronous base counter cells coupled in series, the asynchronous base counter cells having a plurality of input terminals. The multi-bit counter also includes at least one logic gate coupled to at least one of the input terminals of at least one of the plurality of asynchronous base counter cells, a reload signal being input into the asynchronous base counter cells, a clock signal being input into the asynchronous base counter cells, and an input voltage being input into the asynchronous base counter cells, wherein the multi-bit counter is synchronous with the clock signal.

Abstract: A frequency divider (10A) includes an asynchronous finite state machine (AFSM) configured as a counter (20) having an input coupled to an input clock signal (CLK) for producing information representative of a plurality of phase signals (F0,F1,F2,F3) each of which is a divided-down representation of the input clock signal (CLK) and each of which is phase-shifted by a predetermined amount with respect to another of the phase signals (F0,F1,F2,F3). Programmable circuitry (22) operates in response to both dynamic divide ratio information (DIV_RATIO) and the information representative of the plurality of phase signals (F0,F1,F2,F3) so as to generate an output clock signal (CLKOUT) that is divided down according to both the dynamic divide ratio information and the information representative of the plurality of phase signals (F0,F1,F2,F3).

Abstract: A frequency divider for a wireless communication system is provided. A frequency divider includes a body bias voltage generator and a divider. The body bias voltage generator generates a body bias voltage including a PMOS body bias voltage and an NMOS body bias voltage whose voltage levels are controlled according to an input signal. The divider includes a plurality of flip-flops whose operation points are determined according to the body bias voltage, and generates an output signal by dividing a frequency of the input signal by N. Each of the flip-flops may include a PMOS logic and an NMOS logic. The PMOS logic may include a plurality of PMOS transistors whose operation points are determined according to the PMOS body bias voltage. The NMOS logic may be connected electrically to the PMOS logic and include a plurality of NMOS transistors whose operation points are determined according to the NMOS body bias voltage.

Abstract: A frequency divider circuit comprises a plurality of T flip-flops, a first transmission gate, a second transmission gate and an inverter. The plurality of T flip-flops is connected in series. The output of the inverter is connected to a clock input of a first T flip-flop. The first transmission gate connects a clock signal and the other clock input of the first T flip-flop and the input of the inverter. The second transmission gate connects the inverted signal of the clock signal and the output of the first transmission gate.

Abstract: Provided are a programmable frequency divider, more particularly, a programmable frequency divider which is a core module of a frequency synthesizer using a Phase Locked Loop (PLL) for generating very high frequencies.

Abstract: In accordance with the present disclosure, a multi-modulus divider (MMD) circuit configured for operation at high frequencies may include a cascade of multiple divide-by-2-or-3 cells that divides an input clock signal to produce a pulse signal. The MMD circuit may also include a pulse stretching circuit that extends the duration of the pulse signal, thereby outputting an output clock signal. The cascade of divide-by-2-or-3 cells and the pulse stretching circuit may be implemented using full-swing complementary metal-oxide-semiconductor (CMOS) circuits. Each divide-by-2-or-3 cell may be organized so that a critical path of the divide-by-2-or-3 cell comprises a first dynamic flip flop, a second dynamic flip flop, and no more than two logic stages between the first dynamic flip flop and the second dynamic flip flop.

Abstract: Frequency division methods and circuits are provided for producing an output clock signal with a frequency related to the frequency of an input clock signal by a predetermined factor. The method and circuit rely on the input clock signal and on feedback from the output signal to produce an intermediate signal. The frequency of the intermediate signal is divided to produce the output clock signal. The method and circuit may be implemented using few circuit components. In an exemplary embodiment, the method and circuit may be used to produce an output clock signal with a frequency that is two-and-a-half times lower than the frequency of the input clock signal.

Abstract: A frequency divider including a first frequency-dividing unit, a second frequency-dividing unit, a selecting unit, and a counting unit is provided. The first frequency-dividing unit receives an input signal and divides a frequency of the input signal for outputting a plurality of phase signals, wherein phases of the phase signals are mutually different. The selecting unit is connected to the first frequency-dividing unit for selecting one of the phase signals according to a control signal, so as to output an inner signal. The second frequency-dividing unit is coupled to the selecting unit for dividing a frequency of the inner signal to serve an output signal. The counting unit is coupled to the selecting unit for counting the inner signal and outputting a counting result as the control signal. Therefore, the output signal with about 50% duty cycle can be provided.

Abstract: A counter/divider where the counter/divider comprises a: a pre-scaler operable in a first mode to divide an input signal by M and in a second mode to divide the input signal by N, where N is greater than M; a first programmable counter, and a second programmable counter; and where the first and second programmable counters are responsive to an output of the pre-scaler and an output of the first counter controls whether the pre-scaler operates in the first mode or the second mode, wherein the first counter is operable to count to greater than one.

Abstract: Integrated circuit and process for aligning a first signal with a second signal. The integrated circuit includes a single latch, a switch control circuit coupled to an input of the single latch to align an edge of the first signal with an edge of the second signal, and a second switch control circuit coupled to the output of the single latch to produce a 50% duty cycle output.