Abstract: A programmable integer and fractional frequency divider is provided. The programmable divider divides a frequency of an input signal by a first divisor to generate an output signal, and comprises a programmable integer frequency divider and a fractional number switch. The programmable integer frequency divider divides the frequency of the input signal by a second divisor to generate the output signal, wherein the second divisor is first or second integers depending on a divisor switching signal. The fractional number switch calculates a pulse count of the output signal, and generates the divisor switching signal to switch from the first to the second integer when the pulse count of the output signal equals to a predetermined pulse count determined by a fractional part of the first divisor, and receives a fractional divisor control signal to change the predetermined pulse count, thereby changing the fractional part of the first divisor.

Abstract: The present invention relates to a unit counter block. According to an aspect of the present invention, the unit counter block includes a D-flipflop, a second MUX, and a first MUX. The-flipflop outputs first and second output signals in synchronism with a clock signal. The second MUX selects any one of external data and the second output signal of the D-flipflop in response to a data load signal and outputs a selected signal. The first MUX transfers any one of the first output signal of the D-flipflop and the output signal of the second MUX as an input signal of the D-flipflop in response to a counter enable signal or the data load signal.

Abstract: A binary frequency divider includes a counter paced by an input signal, means for comparing a counting value with first and second threshold values and supplying first and second control signals synchronized with variation edges of a first type of the input signal. The divider includes means for supplying at least one third control signal shifted by a half-period of the input signal in relation to one of the first or second control signals, and control means for generating the output signal using control signals chosen according to the value of at least one least significant bit of the division setpoint. Application is mainly but not exclusively to UHF transponders.

Abstract: A frequency divider in accordance with the present invention includes a plurality of latch circuits connected together in series to which a clock signal and an inversion clock signal are input, an inverter circuit to which an output signal from a last connected one of the latch circuits is input, an output terminal to which an output from the inverter circuit is connected, and a plurality of feedback paths that connect the output from the inverter circuit to respective inputs of the plurality of latch circuits. The frequency divider further includes a switching circuit that switches connections to the plurality of feedback paths so that an output signal from the inverter circuit is input to only one of the plurality of latch circuits.

Abstract: The provided fractional frequency divider includes a divider controlling unit for generating a divider selection signal in response to a dual-edge triggering of an input signal and a frequency dividing unit coupled to the divider controlling unit for dividing the frequency of the input signal by one of an integer and a fractional dividers in response to the dual-edge triggering and the divider selection signal to generate the output signal of the fractional frequency divider. An operation of the frequency dividing unit is not suppressed when the integer divider is employed, the operation of the frequency dividing unit is not suppressed for a period of the input signal and is suppressed for half of that period, and this cycle is kept on recurring when the fractional divider is employed. The fractional-n PLL having the fractional frequency divider is also provided.

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: An on-chip clock multiplier for outputting a fast clock that is approximately a predetermined multiple n of a slow clock. The multiplier utilizing a high-speed oscillator to generate a high-frequency base signal. A lower frequency signal is generated using the high-frequency base signal as a function of the output of a rollover counter that counts from a seed value to a terminal value. A saturation counter is used to determine whether no more than n pulses of the lower frequency signal occur within a single cycle of the slow clock. If not, the lower frequency signal is iteratively slowed by changing the seed value until no more than n pulses of the lower frequency signal occur within a single cycle of the slow clock. When this iteration is done, the fast clock having a frequency that is approximately n times the frequency of the slow clock is output.

Abstract: A prescaler that operates in a broad band. The prescaler includes a buffer and a counter. The buffer includes a first amplification circuit, which has three inverter circuits of different drive capacities, a second amplification circuit, which has four series-connected inverter circuits, and a feedback circuit. One of the inverter circuits is connected between a capacitor and an inverter circuit via a first switch circuit and a second switch circuit. This varies the drive capacity of the first amplification circuit. The feedback circuit functions as a variable resistor having two transistors.

Abstract: A modulus divider stage (MDS) includes first and second stages. The MDS receives a modulus divisor control signal S that determines whether the MDS stage operates in a divide-by-two mode or a divide-by-three mode. The MDS stage also receives a feedback modulus control signal from another MDS. When in the divide-by-two mode, the MDS divides by two regardless of the feedback modulus control signal. To conserve power, the first stage is unpowered when the MDS stage operates in the divide-by-two mode. When in the divide-by-three mode, the MDS stage either divides by two or by three depending on the feedback modulus control signal. To further reduce power consumption, the first stage is unpowered when the MDS stage is in the divide-by-three mode but is nonetheless performing a divide-by-two operation. A power-down transistor holds the output of the first stage at the proper logic level when the first stage is unpowered.

Abstract: A divider is provided. The divider includes a first flip-flop, a flip-flop array, a first NOT gate, a second NOT gate, and a circuit. The first flip-flop can be triggered by a frequency signal. The first NOT gate is coupled between a positive output terminal of the last second flip-flop and the first flip-flop. The second NOT gate is coupled between the positive output terminal of the last second flip-flop and the circuit. The first NOT gate and the second NOT gate are controlled by the mode control signal for enabling. If N is an odd number, the circuit includes a wire, and if N is an even number, the circuit includes a third NOT gate.

Abstract: A phase-switching dual modulus prescaler having a dual modulus divider is provided. Said divider comprises a first and second divide-by-2 circuit (A;B), wherein said second divide-by-2 circuit (B) is coupled to the output of said first divide-by-2 circuit (A) and at least said second divide-by-two circuit (B) comprises a four phase output each separated by 90°. A phase selection unit (PSU) is provided for selecting one of the four phase outputs (Ip, In, Qp, Qn; INi, INni, INq, Innq) of the second divide-by-2 circuit (B). Moreover, a phase control unit is provided for providing control signal (C1, NC0; C2, NC2; C3, NC3) to the phase selection unit, wherein the phase selection unit (PSU) performs the selection of the four phase outputs (Ip, In, Qp, Qn; INi, INni, INq, Innq) according to the control signals (C0, NC0; C1, NC1; C2, NC2). Said phase selection unit (PSU) is implemented based on direct logic.

Abstract: A programmable integer and fractional frequency divider is provided. The programmable divider divides a frequency of an input signal by a first divisor to generate an output signal, and comprises a programmable integer frequency divider and a fractional number switch. The programmable integer frequency divider divides the frequency of the input signal by a second divisor to generate the output signal, wherein the second divisor is first or second integers depending on a divisor switching signal. The fractional number switch calculates a pulse count of the output signal, and generates the divisor switching signal to switch from the first to the second integer when the pulse count of the output signal equals to a predetermined pulse count determined by a fractional part of the first divisor, and receives a fractional divisor control signal to change the predetermined pulse count, thereby changing the fractional part of the first divisor.

Abstract: A programmable integer and fractional frequency divider is provided. The programmable divider divides a frequency of an input signal by a first divisor to generate an output signal, and comprises a programmable integer frequency divider and a fractional number switch. The programmable integer frequency divider divides the frequency of the input signal by a second divisor to generate the output signal, wherein the second divisor is first or second integers depending on a divisor switching signal. The fractional number switch calculates a pulse count of the output signal, and generates the divisor switching signal to switch from the first to the second integer when the pulse count of the output signal equals to a predetermined pulse count determined by a fractional part of the first divisor, and receives a fractional divisor control signal to change the predetermined pulse count, thereby changing the fractional part of the first divisor.

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: The present invention generates an output clock signal CLKreq having a frequency freq between the frequency fref/A of a divided clock signal CKL1 and the frequency fref/(A+1) of a divided clock signal CLK2. A clock divider circuit selectively generates divided clock signals CLK1, CLK2. A discrete value correction circuit controls the clock divider circuit so as to repeat C times the process of generating the clock signal CLK2 once and the clock signal CLK1 (Q?1) times and then to generate the clock signal CLK1 R times if C<D and so as to repeat D times the process of generating the clock signal CLK1 once and the clock signal CLK2 (Q?1) times and then to generate the clock signal CLK2 R times if C>D. A, B, and C are natural numbers satisfying freq=fref/(A+C/B). In D=B?C, Q is a quotient of B/C if C<D or a quotient of B/D if C>D.

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 synthesizer (50, 70) including an edge-detection circuit (51, 60) for disabling elements of the frequency synthesizer (50, 70) prior to start-up. The edge-detection circuit detects a transition edge of a reference-clock signal (ref_clk) of the frequency synthesizer (50, 70) and enables elements of the frequency synthesizer (50, 70) upon the detection of the transition edge.

Abstract: A frequency divider comprises a first differential input pair, a second differential input pair, a first capacitive element having first and second ends, a second capacitive element having first and second ends, and four current sourcing elements. The first differential input pair includes first and second transistors that receive a differential local oscillator signal. The second differential input pair includes first and second transistors that receive the differential local oscillator signal. The first capacitive element communicates with first terminals of the transistors of the first differential input pair. The second capacitive element communicates with first terminals of the transistors of the second differential input pair. The four current sourcing elements respectively communicate with the first terminals of the transistors of the first and second differential input pairs.

Abstract: A digital clock divider includes an adder and a clock division device configured to receive a first clock signal with a first frequency and to output a second clock signal having a lower frequency relative to the first frequency. The digital clock divider also includes a division value separation device and a feedback section. The division value separation device is configured to divide an addition value output from the adder into an integer value and a fractional value. The feedback section is configured to provide to the adder a feedback value, the feedback value comprising the fractional component or the fractional component modified by a processing device. The adder is configured to add the feedback value to an applied division value. The clock division device is controlled on the basis of the integer value.

Abstract: A wide-band multimode frequency synthesizer using a Phase Locked Loop (PLL) is provided. The multiband frequency synthesizer includes a multimode prescaler, a phase detector/a charge pump, a swallow type frequency divider, and a switching bank LC tuning voltage-controlled oscillator having wide-band and low phase noise characteristics. The multimode prescaler operates in five modes and divides a signal up to 12 GHz. The wide-band frequency synthesizer can be used in various fields such as WLAN/HYPERLAN/DSRC/UWB systems that operate in the frequency range from 2 GHz to 9 GHz.

Abstract: A divide-by-n process is effected via a scale-by-four/n process followed by a divide-by-four process. A quadrature input clock facilitates a scale-by-four/n process, via a clock-phase selection process. By incorporating a terminal divide-by-four process, quadrature output signals are easily provided. A divide-by-three quadrature divider effects the scale-by-4/n process via a selection of every third quadrature clock phase, and the quadrature output of the divide-by-four process provides the control signals to effect this every-third clock phase selection.

Abstract: Circuits and methods and for dividing a frequency of an input signal by an integer divider value. The circuit generally comprises (a) a first frequency divider, including a first plurality of serially connected delay elements receiving the input signal and a first configurable feedback network, (b) a second frequency divider, including a second plurality of serially connected delay elements receiving an inverse of the input signal and a second configurable feedback network (c) configurable logic configured to select and/or combine outputs of the first and second frequency dividers and to produce a frequency divided output signal, and (d) a programmable circuit configured to selectably configure the first and second configurable feedback networks and the configurable logic. The present invention advantageously provides for a frequency divider structure that can be easily programmed to provide any integer divide ratio with a 50% duty cycle.

Abstract: A binary frequency divider includes a counter paced by an input signal, means for comparing a counting value with first and second threshold values and supplying first and second control signals synchronized with variation edges of a first type of the input signal. The divider includes means for supplying at least one third control signal shifted by a half-period of the input signal in relation to one of the first or second control signals, and control means for generating the output signal using control signals chosen according to the value of at least one least significant bit of the division setpoint. Application is mainly but not exclusively to UHF transponders.

Abstract: A divider circuit receives an input signal and at least one phase adjustment control signal and supplies a phase adjustable output signal. The divider circuit includes a state machine providing N states, with no phase adjustment, to provide as the output signal the input signal divided by N. Each state of the state machine lasts for one period of the input signal. The divider circuit adjusts the phase of the output signal by changing the number of states that occur in one period of the output signal. In response to a control signal to decrement the phase of the output signal, the state machine skips at least one state for one period of the output signal. In response to a control signal to increment the phase of the output signal, the state machine inserts one or more states for one period of the output signal.

Abstract: A dynamic frequency divider circuit with improved leakage tolerance supports a wide frequency range. During the evaluation phase, (1) the input signals can be prevented from changing states, (2) the leakage can be reduced, or (3) both can be implemented to generate the correct output signals. In a architecture-level approach, two dynamic flip-flops can be coupled together. In a circuit-level approach, the dynamic flip-flop can include (1) two additional clocked PMOS transistor added to the inputs of the dynamic flip-flop, or (2) two additional pull-up PMOS transistors to counteract the subthreshold leakage in the NMOS transistors.

Abstract: This invention adds a non-linear sweep accumulator to the conventional sigma-delta fractional-N divider to produce a N.F value that is a polynomial function of time. This allows any non-linear sweep profiles to be approximated.

Abstract: An information handling system including a divider circuit is disclosed that divides an input clock signal by a non integer value to generate an output clock signal. The resultant output clock signal exhibits a 50/50 duty cycle in one embodiment. The disclosed divider methodology permits the design of advanced circuit functions, such as double data rate memory operations, without the need for additional clock signal sources.

Abstract: A low voltage, low power, wideband quadrature divide-by-three frequency divider using a wideband low voltage, low power differential Muller C element with multiple inputs operates on quadrature input and quadrature output signals. This frequency divider can be used in frequency synthesisers and as quadrature local oscillator generator.

Abstract: There is disclosed an apparatus for dividing the frequency of an input signal by an integer N. First and second means may divide the frequency of the input signal by a factor of N and then by a factor of 2. An output of the first means and an output of the second means may be combined by an exclusive OR gate. Third means may be used to control the relative phase of the outputs from the first and second means such that the output from the first means and the output of the second means differ in phase by one-quarter cycle or 90 degrees.

Abstract: A clock divider includes a first state storage unit, a second state storage unit a first control signal generating unit a state update unit and an output unit. The first state storage unit receives an update signal to perform transition of a first state value in synchronization with a clock signal. The second state storage unit performs transition of a second state value in synchronization with a first state signal corresponding to the first state value. The first control signal generating unit generates a first control signal for determining a first state transition path based on a first division ratio control signal. The state update unit generates the update signal based on the first control signal and the first state signal. The output unit selectively output the first state signal or a second state signal corresponding to the second state value.

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: An integrated circuit of an embodiment may comprise synchronous logic, combinational logic, and clock circuitry to clock the synchronous logic through various states dependent on the combinational logic. The synchronous logic may comprise a plurality of master-slave registers. The combinational logic is configured to drive data inputs of the synchronous logic dependent on states established by the master-slave registers. The clock circuitry is configured to clock the master portion of the master-slave registers with a lag rendering of a clock signal and to clock the slave portion of the registers with a lead rendering of the clock signal. In a particular example, the circuitry may define a frequency divider of a complementary CMOS realization.

Abstract: Embodiments of the present invention include circuits and methods for dividing signals. In one embodiment the present invention includes a divider circuit comprising at least one first divider input receiving an in-phase (I+) signal, at least one second divider input receiving a complement of the in-phase (I?) signal, at least one third divider input receiving a quadrature (Q+) signal, and at least one fourth divider input receiving a complement of the quadrature (Q?) signal. In one embodiment, the lock range of a divider is improved by providing a first bias current greater than a second bias current.

Abstract: A frequency-division circuit comprises a pair of multi-state circuits (MSCA, MSCB). Each multi-state circuit can be switched throughout a cycle of states (SA(1), . . . , SA(N); SB(1), . . . , SB(N)). One multi-state circuit (MSCA) switches to a next state in response to a rising edge (Er) in an input signal (OS). The other multi-state circuit (MSCB) switches to a next state in response to a falling edge (Ef) in the input signal (OS). Each multi-state circuit (MSCA, MSCB) has at least one state (SA(1), SB(1)) in which the multi-state circuit inhibits the other multi-state circuit (MSCB, MSCA) so as to prevent the other multi-state circuit from switching to the next state.

Abstract: A digital clock frequency multiplier (100) for increasing an input frequency of an input clock signal includes a generator (102) that receives the input clock signal and a high frequency digital signal. The generator (102) divides a count (Nhf) of a number of cycles of the high frequency digital signal in one period of the input clock signal by a predetermined multiplication factor (MF) for generating an output clock signal. The output clock signal has a predetermined output frequency.

Abstract: A noise shaping arrangement for a phase locked loop includes a first order sigma-delta modulator arranged to provide a first-order quantized output and a feedback path output. A second order sigma-delta modulator is arranged to receive the feedback path output and provides a second order quantized output. A combination block combines the first and second order quantized outputs to provide a combined third order quantized output, which provides noise shaping with a frequency notch spectrum. In this way a new quantization noise shape of third order is provided, such that quantization phase noise may be lowered, the PLL loop bandwidth may be increased, modulation phase error may be reduced and PLL locking speed increased.

Abstract: A frequency dividing circuit includes: a D-type flip flop that outputs frequency-divided signal synchronized with input clock and reverse phase signal corresponding to the frequency-divided signal; a variable delay circuit that generates a delay feedback signal delayed by a specific delay time from the reverse phase signal input from the D-type flip flop and feeds back the delay feedback signal to the D-type flip flop; and a delay adjusting circuit that detects a phase difference between the reverse phase signal input from the D-type flip flop and the delay feedback signal input from the variable delay circuit, obtains detected results, and outputs to the variable delay circuit a control signal to perform control so that the delay time becomes time required to ensure setup/hold time of the D-type flip flop, based on the detected results.

Abstract: A method for dividing a plurality of multiphase signals comprising performing resetable divider stages to the plurality of multiphase signals forming a plurality of divided multiphase signals having a monotonic increasing phase with equal spacing and an ideal duty cycle of 50% through a plurality of resetable dividers, wherein the plurality of divided multiphase signals have no phase ambiguity; and producing a plurality of periodic reset signals to the plurality of resetable dividers to enable the plurality of resetable dividers to divide the plurality of multiphase signals in a timely correct sequence to form the divided multiphase signal through a reset signal generator, the plurality of periodic reset signals being produced by a combinational network of the reset signal generator, the combination network is configured for generating a number of pulses based on the plurality of multiphase signals and performing a plurality of decimation stages and wherein the periodic reset signals are generated solely in r

Abstract: Within a mobile communication device (for example, a cellular telephone), there is a local oscillator. The local oscillator includes a novel frequency divider that includes a novel configurable multi-modulus divider (CMMD). The frequency divider is configurable into a selectable one of multiple configurations involving different mixes of synchronous and asynchronous circuitry. In each configuration, the frequency divider produces an amount of noise and consumes an amount of power. Power consumption is loosely inversely related to noise produced in that the modes with the highest power consumption produce the least amount of noise, and vice versa. The mobile communication device is operable in one of multiple different communication standards (for example, GSM, CDMA1X and WCDMA). The different communication standards impose different noise requirements on the frequency divider.

Abstract: The present invention relates to frequency dividers. The frequency divider comprises an input, a counter, a first comparator, an interconnect, and an output. The counter has a counter reset port and is configured to receive a clock signal from the input and to produce a sum signal. The first comparator is configured to receive the sum signal, to compare the sum signal to a first integer, and to produce a first comparison signal. The interconnect is configured to convey the first comparison signal from the first comparator to the counter reset port. The output coupled to the first comparator. The clock signal has a periodic waveform. The sum signal represents a first sum, which equals a number of waveforms of the clock signal received by the counter after the counter has been reset. In a first embodiment, the first integer is selectable from a set of at least three consecutive integers. In a second embodiment, a frequency of the clock signal is at least 1.5 gigahertz.

Abstract: We describe a dual modulus prescaler that may be used in a high frequency PLL. The prescaler comprises a frequency division unit to generate a prescaled signal by dividing a frequency of an input signal by a division ratio and a frequency division ratio controller to determine the division ratio responsive to a count signal and the prescaled signal. The frequency division unit divides a frequency of an input signal by a division ratio of 2N or (2N?1) to output a prescaled signal. The frequency division ratio controller determines a division ratio responsive to a count signal and the prescaled signal.

Abstract: A multiphase divider includes a plurality of resetable dividers configured for performing resetable divider stages to a plurality of multiphase signals forming a plurality of divided multiphase signals having a monotonic increasing phase with equal spacing and an ideal duty cycle of 50%, wherein the plurality of divided multiphase signals have no phase ambiguity; and a reset signal generator configured for producing a plurality of periodic reset signals to the plurality of resetable dividers to enable the plurality of resetable dividers to divide the plurality of multiphase signals in a timely correct sequence to form the divided multiphase signal, the plurality of periodic reset signals being produced by a combinational network of the reset signal generator, the combinational network is configured for generating a number of pulses based on the plurality of multiphase signals and performing decimation stages to reduce the number of pulses within the pulse traces.

Abstract: The frequency divider for high-frequency clock signal comprises: a shift register (8) having cells (10-13) for storing each bit of an initial word, said cells being series connected in a loop (14), and said shift register being capable of shifting each bit of the initial word from the cell in which it is stored to the next cell in the loop at a rate clocked by the high-frequency clock signal, and wherein an output terminal (6) for outputting a frequency-divided clock signal is connected to the output of one cell of the loop of series-connected cells.

Abstract: A programmable frequency divider for dividing the frequency of a source signal according to a selectable divisor which is obtained based on a plurality of divisor signals and outputting a result signal having a divided frequency includes at least one cell of a first type. The cells of the first type are cascaded with each other. The programmable frequency divider synchronously resets all of the cells of the first type according to a reset signal in order to selectively switch each cell of the first type to perform a divide-by-two or divide-by-three operation according to a corresponding divisor signal. The last cell of the first type outputs the result signal having the divided frequency.

Abstract: Disclosed is an apparatus for multiple-divisor prescaler, which includes an odd/even core divider, a divisor control logic unit, an odd number inserted mechanism, and an n-order divided-by-2 divider with changeable trigger edges. This invention uses a clock toggle mechanism to vary the trigger edges of each divided-by-2 divider in the n-order divider, and associates the odd/even core divider to realize the multiple-divisor prescaler apparatus. Thereby, it achieves the purpose of being divided by 30/31. In addition, it increases the divisor range up to 2n?1+2 and 2n+1 through the use of the clock toggle mechanism.

Abstract: The invention is directed to a phase locked loop with a ?? modulator. A multimodulus divider in the feedback path of the PLL is actuated by the ?? modulator. The latter has a design which can be described by a complex transfer function H(s) in the Laplace plane, said transfer function having a complex-conjugate pair of pole points. The arrangement allows a significant reduction in the noise in critical frequency domains and hence allows adherence to transmission masks based on radio specification even when the PLL bandwidth is as large as the modulation bandwidth.

Abstract: A prescaler that operates in a broad band. The prescaler includes a buffer and a counter. The buffer includes a first amplification circuit, which has three inverter circuits of different drive capacities, a second amplification circuit, which has four series-connected inverter circuits, and a feedback circuit. One of the inverter circuits is connected between a capacitor and an inverter circuit via a first switch circuit and a second switch circuit. This varies the drive capacity of the first amplification circuit. The feedback circuit functions as a variable resistor having two transistors.

Abstract: A clock multiplication circuit simple in configuration, easy to adjust the characteristics thereof, and capable of shortening lockup time. The circuit delivers an output clock signal at a frequency that is a multiple of the frequency of a reference clock signal as inputted. A counter counts the number of rising edges of the output clock signal existing during a High level period of the reference clock signal, delivering a count value CN. A subtracter subtracts the count value from a reference value BN, delivering a difference value DN. An adder adds the difference value to a preceding integrated value, calculating a new integrated value. A DA converter delivers the analog control voltage corresponding to the integrated value. A VCO delivers the output clock signal at a frequency corresponding to the analog control voltage. The frequency of the output clock signal is controlled such that DN=BN?CN=0.

Abstract: In rotating systems with angular references, angular- and/or time-based pulses must be generated which can be described in a generic manner to meet various requirements. The parameters for definition of the pulse are assigned as a value pair to permit more flexibility on definition of a pulse for generation, one value of which defines the type of the parameter, in other words, whether an angle, a time, or some other parameter is being defined. A calculation device can correctly assign the size value of the parameter using the additional value, interpret and carry out suitable subroutines to calculate the control values for controlling the relevant pulse generation circuits.

Abstract: The present invention relates to a structure of a delta-sigma fractional type divider. The divider structure adds an external input value and an output value of a delta-sigma modulator to modulate a value of a swallow counter. Therefore, the present invention can provide a delta-sigma fractional type divider the structure is simple and that can obtain an effect of a structure of a delta sigma mode while having a wide-band frequency mixing capability.