Abstract: The invention features an output driver for integrated circuits that includes a driver that has a data input connected to the integrated circuit, a data output connected to a transmission line leading to the external circuit, and impedance adjusting means for adjusting the output impedance of the driver circuit according to determinable impedance adjusting data. The output driver also includes a dummy circuit having a dummy driver circuit and transmission line, and an impedance control circuit for controlling the output impedance of the driver circuit. The impedance control circuit controls the impedance of the driver circuit by determining the impedance adjusting data (necessary for matching the output impedance of the dummy driver circuit to the characteristic impedance of the dummy transmission line and outputting the determined impedance adjusting data to the impedance adjusting means of the driver circuit.

Abstract: A method (and structure) of generating a two step variable length delay, including passing an input clock signal through a plurality of serially-interconnected delay elements, each delay element having a delay time interval dtc, thereby generating a corresponding plurality delayed signals. A set of m (where m is an integer greater than 2) of the plurality of delayed signals is switably selected. The selected m delayed signals form a first to an mth coarse adjustment delay signals. An nth coarse adjustment delay signal leads an (n+1)th coarse adjustment delay signal in phase by a time interval dtc (n is an integer being 1 or more and (m−1) or less). From the first to mth coarse adjustment delay signals, 2m fine adjustment delay signals are generated, where a jth fine adjustment delay signal leads a (j+1)th fine adjustment delay signal in a phase by a time interval dtc′, where time interval dtc′ is finer than the time interval dtc.

Abstract: A circuit and method is shown for digital control of delay lines in a delay locked loop (DLL) system. A pair of multiplexors (MUXes) is used to select output taps from a pair of complementary delay lines that delay a reference clock signal in order to lock onto a received clock signal. An output tap from one delay line is used to produce a rising edge in an output clock signal while a corresponding tap in the complementary delay line is used to produce a falling edge in the output signal in order to correct for distortion. The MUXes are controlled based on a phase difference detected between the received clock signal and a feedback clock corresponding to the output clock signal. Another aspect of the present invention provides for generation of a quadrature clock by interpolating between the rising and falling edges selected for the output clock signal. Still another aspect of the present invention provides for selectively disabling unused elements of the delay lines to reduce power consumption.

Abstract: A method and apparatus for compensating a delay locked loop against signal timing variances after circuit initialization which cause delay shifts due to temperature and voltage changes and operational noise. A delay line of a delay locked loop is disclosed, the delay line having a plurality of delay elements and a minimum and maximum delay boundary. According to an embodiment of the invention, an artificial minimum or maximum boundary, or both, is established on the delay line such that during initialization of the delay locked loop circuit, the circuit cannot lock on a delay element beyond the artificial minimum or maximum boundaries. By offsetting the artificial minimum and maximum boundaries from the actual minimum and maximum boundaries of the delay line, a buffer of delay elements is established at the actual delay line boundaries.

Abstract: A method and apparatus for delay tuning an integrated circuit which includes a delay element that includes a plurality of delay stages interconnected in a cascaded relationship, each stage imposing an incremental delay upon the input signal when enabled, the delay element receives a selection signal that determines how many of the delay stages are enabled. By varying the select signal, the delay element imposes a variable delay upon the input signal for testing and evaluation.

Abstract: An apparatus comprising an analog delay line and a control circuit. The analog delay line may be configured to generate an output signal in response to an input signal, a first control signal, and a second control signal. A phase of the output signal may be (i) coarsely adjustable with respect to the input signal in response to the first control signal and (ii) finely and continuously adjustable in response to the second control signal. The control circuit may be configured to generate the first and the second control signals in response to the input signal and the output signal.

Abstract: A delay line receives an input clock signal and includes a cascaded plurality of unit delay circuits. A mode register set stores a value indicative of a column-address-strobe (CAS) latency of the memory device, and an adjustment circuit varies a delay time of the unit delay circuits according to the CAS latency stored in the mode register set. A phase detector detects a phase difference between the input clock signal and an output clock signal of the delay line, and a control circuit which controls an enabled state of the unit delay circuits according to an output of said phase detector.

Abstract: The invention relates to a system (2) of a control unit (4) and a logic application (6), wherein the control unit (4) and the logic application (6) are connected to a system clock, wherein the logic application (6) comprises a series connection (16) of logic elements (18), wherein, in use, the system clock generates a clock signal (8) and feeds this clock signal to the control unit (4) and the logic application (6), and wherein the control unit (4) controls the supply voltage of the series connection (16) on the basis of the clock signal (8) such that the delay time of the series connection (16) is substantially equal to a predetermined value.

Abstract: A delay cell has selectable numbers of parallel load resistance transistors operable in parallel, and a similarly selectable number of bias current transistors connectable in parallel. The delay cell is preferably differential in construction and operation. A voltage controlled oscillator (“VCO”) includes a plurality of such delay cells connected in a closed loop series. Phase locked loop (“PLL”) circuitry includes such a VCO controlled by phase/frequency detector circuitry. The PLL can have a very wide range of operating frequencies as a result of the ability to control the number of load resistance transistors and bias current transistors that are active or inactive in each delay cell. Such activation/deactivation may be programmable or otherwise controlled.

Abstract: A digital frequency doubler circuit employs a stable reference clock signal, delayed by a reference delay line, to obtain information related to delay characteristics of a matching input delay line. An input clock signal is delayed by the input delay line, which provides a plurality of variously delayed input clock signals based upon the input clock signal. The reference delay line provides a plurality of variously delayed reference clock signals based upon the stable reference clock signal; the delayed reference clock signals convey information related to the operating characteristics of both delay lines. In response to such information, one of the delayed input clock signals can be selected as a delayed clock output. The reference and input delay lines are configured such that the delay circuit consistently generates a delayed clock output having an actual delay that falls within a specified range of delay.

Abstract: A semiconductor integrated circuit includes a logic circuit which is formed of p-channel MIS transistors and n-channel MIS transistors, a first oscillation circuit of variable oscillation frequency which is formed of p-channel MIS transistors and n-channel MIS transistors, a control circuit which produces a control signal for controlling the threshold voltage of the p-channel and n-channel MIS transistors, and a second oscillation circuit which produces multiple reference clock signals of different frequencies depending on the operation mode. The control circuit receives a reference clock signal and controls first oscillation circuit with the control signal so that the oscillation frequency of the first oscillation circuit corresponds to the frequency of the reference clock signal.

Abstract: A digital delay circuit employs a stable reference clock signal, delayed by a reference delay line, to obtain information related to delay characteristics of a matching input delay line. An input clock signal is delayed by the input delay line, which provides a plurality of variously delayed input clock signals based upon the input clock signal. The reference delay line provides a plurality of variously delayed reference clock signals based upon the stable reference clock signal; the delayed reference clock signals convey information related to the operating characteristics of both delay lines. In response to such information, one of the delayed input clock signals can be selected as a delayed clock output. The reference and input delay lines are configured such that the delay circuit consistently generates a delayed clock output having an actual delay that falls within a specified range of delay.

Abstract: A delay time controlling circuit in a semiconductor memory device and method thereof for controlling a delay time preferably comprise a controller, a fuse unit having selectable fuse elements, a multiplexer, and a programmable variable delay circuit. With the multiplexer selecting the output of the controller, the controller generates a sequence of differing digital delay control signals to the programmable variable delay circuit in order to provide a plurality of unique delays in an output signal. When a desired time delay is monitored in the output signal, a programming signal is generated, which causes the specific digital control signal to be permanently programmed into the fuse unit via selective cutting of fuse elements. The multiplexer is then toggled via a selector fuse element to permanently select the output of the fuse unit as a control value source for the variable delay circuit.

Abstract: A method and apparatus for restoring tracking in a circuit in which gate and metal capacitance vary independently. The present invention allows Shoji balancing to be extended to the situation where the gate and metal capacitance in a circuit vary independently across a process window. This is accomplished by regarding the inverting stage in a clock distribution system as a buildup mirror and applying the tracking principles of proportional composition. Loads are reflected through this mirror and resized by the buildup factor to extend Shoji balancing from just one process parameter setting to the entire process window.

Abstract: A variable delay circuit comprises: a delay compensation unit, which has a plurality of referential delay units that include different numbers of first variable delay elements, the delay amount of which varies based on a control signal, the delay compensation unit generates each of a plurality of the control signals, which are provided to the first variable delay elements, according to a number of the first variable delay elements; and a delay unit which generates the desired delay amount by controlling a plurality of second variable delay elements, which have a same characteristic with the first variable delay elements, by the plurality of control signals.

Abstract: A phase adjustment circuit has a signal path having a plurality of phase adjustment elements coupled together. Each of the phase adjustment elements of the plurality has a first path and a second path. The second path of each of the phase adjustment elements of the plurality adds a smaller amount of phase adjustment to the signal path than the first path of each of the phase adjustment elements of the plurality. The amount of phase adjustment added by each of the phase adjustment elements of the plurality is cumulative. The phase adjustment circuit also has a selection circuit coupled to each of the phase adjustment elements of the plurality to provide selection of either the first path or the second path of each of the phase adjustment elements of the plurality.

Abstract: A composite delay line includes a first and a second delay line connected to a multiplexer. The multiplexer has a first and a second input. The first delay line includes an input, an output and first control means for controlling delay. The second delay line includes an input, an output and second control means for controlling delay. The output of each delay line is connected to the input of the multiplexer. Control logic connected to the first control means selects a delay through the first delay line. Control logic connected to the second control means selects a delay through the second delay line. Control logic connected to the multiplexer selects between the output of the first delay line and the second delay line.

Abstract: A DLL (delay locked loop) circuit includes a signal propagation system and a delay control system. The signal propagation system includes a delay circuit which delays a reference clock signal based on a delay control signal to generate a delayed clock signal. The delay control system includes a sampling circuit, a phase comparing circuit and a delay control circuit. The sampling circuit outputs a first clock signal having a pulse corresponding to one of n (n is an integer more than 1) pulses of the delayed clock signal. The phase comparing circuit compares the first clock signal as a first comparison input signal and the reference clock signal as a second comparison input signal in phase to output a phase difference. The delay control circuit generates the delay control signal based on the phase difference from the phase comparing circuit to output to the delay circuit of the signal propagation system.

Abstract: A delay time controlling circuit in a semiconductor memory device and method thereof for controlling a delay time preferably comprise a controller, a fuse unit having selectable fuse elements, a multiplexer, and a programmable variable delay circuit. With the multiplexer selecting the output of the controller, the controller generates a sequence of differing digital delay control signals to the programmable variable delay circuit in order to provide a plurality of unique delays in an output signal. When a desired time delay is monitored in the output signal, a programming signal is generated, which causes the specific digital control signal to be permanently programmed into the fuse unit via selective cutting of fuse elements. The multiplexer is then toggled via a selector fuse element to permanently select the output of the fuse unit as a control value source for the variable delay circuit.

Abstract: A delay compensation circuit that determines the effects of process, voltage, and temperature (PVT) conditions of a chip by amplifying the maximum delay time of a delay element within the chip. The delay compensation circuit determines into which one of several predefined time intervals the amplified delay time falls, where each predefined time interval is associated with different PVT conditions. The delay compensation circuit of the present invention can be used to generate control signals for a variable delay element. Also, the PVT information provided by the delay compensation circuit can be used to design components within a chip to compensate for variances in PVT conditions. The feedback loop structure of the delay compensation device reduces the required chip area and power consumption of the delay compensation circuit.

Abstract: A programmable delay element comprises a plurality of delay modules (d, d′), which can be connected together for generating, starting from an input signal (IS), an output signal (OS) delayed with a pre-determined time-delay value referred to a given value (T) of operating period. A control logic (LC) selectively connects together the delay modules (d, d′) in such a way as to obtain the aforesaid pre-determined time-delay value. The arrangement is such that the jitter present on the delayed output signal (OS) is made to vary proportionally to the operating period (T) so as to maintain the ratio between said period (T) and said jitter substantially constant. The element is usable in particular in memories of the DDR-SDRAM type for generating the delayed DQS signal (DQS_delayed) with the possibility of varying selectively the amount of delay as a function of the frequency (T) of operation of the memory.

Abstract: A system and method of controlling delay in a delay line. In a delay line having a system mode and an oscillator mode, wherein the delay line delays a signal as a function of a delay code, the method comprises setting the delay code, placing the delay line in oscillator mode, determining frequency of oscillation of the delay line, comparing the frequency of oscillation to a target frequency and adjusting the delay code until the frequency of oscillation of the delay line is substantially equal to the target frequency.

Abstract: A DLL circuit includes a delay line having a configuration with delay stages receiving alternate complementary clock signals ECK and /ECK having an adjusted phase difference therebetween. A capacitor can be used to adjust the phase difference between signals ECK and /ECK to allow the delay line to provide an amount of delay varying minutely. Preferably, for a fast clock, delay adjustment starts with a shift register having an initial value providing an intermediate amount of delay, and for a slow clock, delay adjustment starts with the shift register having an initial value providing a minimal amount of delay. There can be provided a semiconductor device provided with a DLL circuit accommodating a fast clock with reduced jitter.

Abstract: Circuitry that provides additional delay to early arriving signals such that all data signals arrive at a receiving latch with same path delay. The delay of a forwarded clock reference is also controlled such that the capturing clock edge will be optimally positioned near quadrature (depending on latch setup/hold requirements). The circuitry continuously adapts to data and clock path delay changes and digital filtering of phase measurements reduce errors brought on by jittering data edges. The circuitry utilizes only the minimum amount of delay necessary to achieve objective thereby limiting any unintended jitter. Particularly, this programmable differential delay circuit with fine delay adjustment is designed to allow the skew between ASICS to be minimized. This includes skew between data bits, between data bits and clocks as well as minimizing the overall skew in a channel between ASICS.

Abstract: A semiconductor integrated circuit comprises a logic circuit which is formed of p-channel MIS transistors and n-channel MIS transistors, a first oscillation circuit of variable oscillation frequency which is formed of p-channel MIS transistors and n-channel MIS transistors, a control circuit which produces a control signal for controlling the threshold voltage of the p-channel and n-channel MIS transistors, and a second oscillation circuit which produces multiple reference clock signals of different frequencies depending on the operation mode. The control circuit receives a reference clock signal and controls the first oscillation circuit with the control signal so that the oscillation frequency of the first oscillation circuit is correspondent to the frequency of the reference clock signal.

Abstract: An object of the present invention is to simply and rapidly adjust a delay time of a delayed clock signal in accordance with a change in frequency of an input clock signal. The present invention comprises: a pulse generating circuit for generating a pulse signal PULSE with a trailing edge of an input clock signal as a reference; an inverter chain consisting of a plurality of inverters; a pair of inverter chains for sequentially delaying output signals from the pulse generating circuit; a plurality of NOR gates for adjusting a delay time of each inverter in the inverter chain; and a plurality of NAND gates for similarly adjusting a delay time of each inverter in the inverter chain. Since the delay time of the delayed clock signal in a next cycle is set based on the pulse signal generated based on a trailing edge of the input clock signal, even if a cycle of the input clock signal varies, the delay time of the delayed clock signal can be rapidly changed in accordance with this variation.

Abstract: A controlled delay circuit has a first gate chain, and a second gate chain. The first gate chain is used to measure a time difference between a changeover point of a first control signal and a changeover point of a second control signal. The second gate chain, which receives third signals generated in the first gate chain and representing the time difference, is used to provide an appropriate delay time from an input to an output depending on the time difference. The controlled delay circuit is capable of properly controlling the timing of the control signal according to the period of the control signal.

Abstract: The variable delay circuit has a delay circuit and a selector. The delay circuit is formed of a plurality of delay stages connected in cascade. The delay circuit receives an input signal at the initial delay stage and respectively outputs a delayed signal which is the input signal delayed, from the delay stages. The selector receives the delayed signals and selecting signals respectively corresponding to the delayed signals. The selector selects the delayed signal corresponding to an activated selecting signal and outputs the selected signal as a delayed output signal. The delay stage(s) subsequent to the delay stage outputting the delayed signal selected by the selector is/are inactivated. Not operating unnecessary delay stages can prevent wasteful power consumption.

Abstract: The invention comprises a device that internally self-generates a clock signal, and provides methods for adjusting the clock signal through the use of a reference frequency. The device is composed of a plurality of propagation delay devices. The propagation devices can be individually selected as to allow a signal to propagate through them, or to not allow a signal to pass. The device creates a clock signal by setting a logical condition at the start of the propagation devices, allowing a signal to pass through, and then changing the inputted logical condition. The time it takes to pass through the devices depends on the number of devices selected. Therefore with the changing of the logical conditions at the output of the device a clock signal can be created. To determine the frequency of the output signal, the output is compared to a known frequency of a reference signal which can originate from an inexpensive external crystal oscillator.

Abstract: A digital-to-analog converter circuit includes a converter configured to convert digital signals of bit n (n=0, 1, 2, . . . , N) to voltage values, a plurality of amplifiers configured to output currents having different values in accordance with the voltage values, and an adder configured to assigning weights to the currents and adding the currents together in response to the digital signal of bit n.

Abstract: A delay lock loop circuit is disclosed which includes a delay block which receives the clock signal and delays the clock signal by a selected amount to generate the delayed clock signal. A phase detector receives the clock signal and the delayed clock signal, compares the phases of the two signals and generates a phase comparison signal. A lock detector receives the clock signal and the delayed clock signal, compares the timing of the two signals and generates a potential lock indication signal. A controller receives the phase comparison signal and the potential lock indication signal and provides a delay control signal to the delay block to change the selected delay amount in response to the phase comparison signal. The controller interrupts the clock signal to the delay block for a selected interval in response to the potential lock indication signal, and generates a true lock indication signal in response to the potential lock indication signal after the interruption of the clock signal to the delay block.

Abstract: A circuit generating memory clock with phase advance and delay capability is provided. The phase of the memory clock is controlled by adjusting the configuration register bits. The circuit allows for a high degree of control and flexibility in the memory clock generation in that the memory clock relationship with respect to the memory command and data can be adjusted independently, thereby creating the ability to effectively adjust the memory interface timings such as setup time, hold time, and memory read data access time. Specifically, 0, 90, and 180 degree phase advance ability is combined with the ability to add delay in fine increments to achieve a more granular degree of phase adjustment.

Abstract: A controlled delay circuit has a first gate chain, and a second gate chain. The first gate chain is used to measure a time difference between a changeover point of a first control signal and a changeover point of a second control signal. The second gate chain, which receives third signals generated in the first gate chain and representing the time difference, is used to provide an appropriate delay time from an input to an output depending on the time difference. The controlled delay circuit is capable of properly controlling the timing of the control signal according to the period of the control signal.

Abstract: An area-efficient delay cell utilizes transistor stacks to control positive feedback responsive to a counter code, thereby controlling the hysteresis and overall signal delay of the cell. The code-delay response of the cell can be modified by freezing the counter code at a convenient value. Linear superposition of the responses of one modified cell connected in series with one unmodified cell provides a more linear overall response and reduces jitter when used in a delay locked loop.

Abstract: In an improved charge pump bias generating circuit for a charge pump for a semiconductor integrated circuit device, the pump has a bias generator which has an input for receiving a pump enable signal. The bias generator generates a ramped bias signal in response to the pump enable signal. A voltage controlled oscillator has an input to receive the ramped bias signal and generates an oscillating signal having a frequency which is dependent upon the voltage of the ramped bias signal. As a result, the sudden turn on of the pump enable signal would cause a gradual turn on of the voltage controlled oscillator gradually turning on the clock output signal from the voltage oscillator, thereby reducing power surge in the circuit.

Abstract: A delay-locked loop includes two delay lines. One line provides variable coarse delay adjustments, while the other delay provides variable fine delay adjustments. By providing two delay lines—one coarse and one fine—the dual delay line configuration of the preferred DLL allows the DLL to exhibit a wide dynamic range to accommodate large on-chip process delay deviations among the clocks to be matched and at the same time exhibit fine-grain delay settings to enable accurate phase matching between the clocks.

Abstract: Complementary data line driver circuits conserve power by evaluating data on complementary data lines and providing conditional charge recycling in the event the new data to be provided to the complementary data lines differs from the old data residing thereon. These devices and circuits include first and second data lines within a complementary data line pair and a driver control circuit that is electrically coupled to the data line pair. The driver control circuit compares the old data on the data line pair against new data to be provided to the data line pair. Based on the comparison and determination that the old data is opposite the new data, the driver control circuit switches the old data to the new data in two steps. The first of the two steps includes transferring charge from the more positively biased one of the first and second data lines to the other data line in the data line pair, preferably for a duration sufficient to substantially equilibrate voltages on the first and second data lines.

Abstract: In a synchronous delay circuit including a first delay circuit array which is constituted of a plurality of cascade-connected delay circuit stages, and a second delay circuit array which is constituted of a plurality of cascade-connected delay circuit stages arranged to have a signal propagating direction opposite to that of the first delay circuit array. Each of the delay circuit stages of the first and second delay circuit arrays includes a CMOS inverter receiving an input signal. A P-channel MOS transistor of the CMOS inverter, a switching P-channel MOS transistor and an additional resistor are connected in series between a power supply line and an output node of the delay circuit stage. An N-channel MOS transistor of the CMOS inverter, a switching N-channel MOS transistor and another additional resistor are connected in series between the ground and the output node of the delay circuit stage.

Abstract: A delay circuit in accordance with the present invention includes: a first I2L inverter and a second I2L inverter connected in cascade with each other; and a capacitor interposed between a ground and a connecting point of the first and second inverters, wherein: the delay circuit further includes a current adjusting circuit having at least one third I2L inverter with a plurality of output terminals at least one of which is connected to an input terminal of the third I2L inverter; and the current adjusting circuit is connected to adjust a charge current of the capacitor. The configuration provides a delay circuit of simple circuit structure that accounts for a small area in an integrated circuit and that is capable of introducing any given delay and also provides a ring oscillator incorporating the delay circuit.

Abstract: A clock modulator for in-vehicle electronic equipment requiring an EMI countermeasure optimally reduces undesired radiant noise by a low spectral dispersion number. A delay circuit has delay buffers DB0 to DB30 connected in series with each other, each outputting an output pulse delayed from an input pulse by a phase delay time &tgr;, and a selection circuit sequentially selecting an output pulse outputted from each of the delay buffers DB0 to DB30. Adjustment is made such that with respect to an input CLK inputted to the delay buffer DB0, a phase variation amount of the output pulse from the delay buffer DB0 and a phase variation amount of the output pulse from the delay buffer DB30 are near ±45° when a phase of the output pulse from the delay buffer DB15, at a center position of the delay buffers DB0 to DB30, is made a reference.

Abstract: Disclosed is a clock period sensing circuit in which it is possible to broaden the operating range of phase adjustment and frequency multiplier circuits, etc., by performing coarse period adjustment in advance. A plurality of delay sensing circuits having slightly overlapping operating ranges and different centers of operation are connected in parallel with respect to a an input clock signal, which is passed through the delay sensing circuits. The period of the clock is sensed coarsely in short periods using a signal which identifies delay sensing circuits through which the clock signal has passed and delay sensing circuits through which the clock signal has not passed.

Abstract: A semiconductor integrated circuit includes a logic circuit which is formed of p-channel MIS transistors and n-channel MIS transistors, a first oscillation circuit of variable oscillation frequency which is formed of p-channel MIS transistors and n-channel MIS transistors, a control circuit which produces a control signal for controlling the threshold voltage of the p-channel and n-channel MIS transistors, and a second oscillation circuit which produces multiple reference clock signals of different frequencies depending on operation mode. The control circuit receives a reference clock signal and controls first oscillation circuit with the control signal so that the oscillation frequency of the first oscillation circuit corresponds to the frequency of the reference clock signal.

Abstract: A clock control circuit for reducing jitter has at least one averaging circuit for generating, and outputting from an output terminal, a signal having a time difference obtained by internally dividing a time difference between first and second signals input respectively from first and second input terminals. First and second clock signals are supplied respectively to the first and second input terminals of the timing averaging circuit, and a clock in which a time difference between pulses of the first and second clock signals is averaged is generated.

Abstract: A voltage-controlled CMOS delay cell includes a pair of inverters and a pair of load cells. The load cells are controllable by independent N and P bias control voltages to vary the delay of the delay cell. Symmetric P and N load capacitors in the delay cells, together with the N and P bias control voltages, provide effective rejection of noise on the power supply rails and enable the delay cell to generate symmetric low-going and high-going delays. The P bias control voltage is generated from the N bias control voltage by a closed-loop voltage control circuit. Also described are a voltage-controlled load cell, an integrated circuit, an electronic system, and a data processing system that incorporate one or more of the symmetric CMOS voltage-controlled delay cells.

Abstract: A delay locked loop based clocking circuit includes a lead delay line followed by a period delay line. The lead delay line receives an input clock signal and includes an analog delay control input. The period delay line has a plurality of taps and an analog delay control input, and is operated such that the N taps divide a single period of an input clock. A selected tap of the period delay line, sometimes called a “virtual zero-degree tap,” is fed back and phase-compared with the input clock signal to adjust the delay of the lead delay line.

Abstract: In a multiplying circuit for providing a pulsed output clock signal having a frequency that is a multiple of a pulsed input clock signal, a delay of a digital delay line is initialized by initializing a counter when an external reset signal is input and when the number of pulses of the output clock signal from the clock generator is smaller than a predetermined multiplier. The delay of the digital delay line is set to a minimum value immediately following the initialization and then increased gradually in order to output the desired output clock signal.

Abstract: A controlled delay circuit has a first gate chain, and a second gate chain. The first gate chain is used to measure a time difference between a changeover point of a first control signal and a changeover point of a second control signal. The second gate chain, which receives third signals generated in the first gate chain and representing the time difference, is used to provide an appropriate delay time from an input to an output depending on the time difference. The controlled delay circuit is capable of properly controlling the timing of the control signal according to the period of the control signal.

Abstract: An elementary cell structure for programmable time-continuous analog filters and in particular for the processing of analog signals in read/write operations on magnetic supports comprises an amplifier stage provided with a pair of structurally identical transconductance half-cells connected together in a common circuit node. With a cascade of cells of this type is provided a time-continuous analog delay line which is used in a transverse time-continuous analog filter. This filter comprises a cascade of identical delay lines connected through multiplier nodes to a final summation node.

Abstract: A universal clock generator circuit, in accordance with the present invention, includes an oscillator unit including circuitry for providing a first clock frequency. A plurality of load blocks are included. The load blocks are selectively connectable to the oscillator such that a range of clock rates are derived from the first clock frequency by selectively connecting a number of the load blocks to the oscillator unit to provide one of a plurality of clock frequencies from a same output.

Abstract: An integrated circuit has a plurality of signal paths, at least one of which has a delay cell. The delay cell has an input terminal for receiving an signal from the signal path, and a plurality of delay paths for generating a corresponding plurality of delayed signals delayed by different delays from the input signal. At least one of the delay paths employs two different-delay subpaths coupled in parallel to provide a delayed signal delayed by an interpolated delay. A multiplexer (MUX) of the delay cell provides one of the delayed signals as an output signal to the signal path based on a control input signal applied to the multiplexer.