169results about "Pulse generation by differential amplifiers" patented technology

A ring oscillator includes a coarse delay control block including a plurality of coarse delay gates, and a fine delay control block including a plurality of fine delay gates. The total delay of the fine delay control block is larger than a single delay step of the coarse delay control block, whereby variations of the delay step do not cause an adverse effect on the jitter characteristic of a PLL circuit having the ring oscillator. In a normal operation, the coarse delay control block increments the delay step after the total of the delay steps of the fine delay control block exceeds the delay step of the coarse delay control block.

The invention provides a relaxation oscillator of which the linearity is significantly improved. The relaxation oscillator comprises an oscillating circuit, a reference level self-regulating circuit and a transmission gate selective signal generating circuit. Capacitor voltage overshoot caused by delay of a control circuit is worked out by detecting the voltage peak of charge and discharge capacitors in the oscillating circuit, and accordingly the reference level of comparators in the oscillating circuit is reduced by a corresponding quantity to serve as a new reference level so that the oscillation amplitude of the charge and discharge capacitors can be just a theoretical value. According to the high-linearity relaxation oscillator, when the new reference level is larger than zero, influence, brought by the capacitor voltage overshoot caused by delay of the control circuit, of the charge and discharge capacitors on output frequency is eliminated, and the linearity of a frequency-control circuit of the relaxation oscillator is significantly improved. The transmission gate selective signal generating circuit provides the initial reference level for the comparators by controlling transmission gates and transmits the new reference level to the reverse phase ends of the comparators when the new reference level is generated, and therefore the initial reference level can be isolated from the reverse phase ends of the comparators.

A multiple output current stimulator circuit with fast turn on time is described. At least one pair of input side and output side transistors is arranged in a current mirror connected to a supply transistor by cascode coupling. The output side transistor supplies stimulation current to an electrode in contact with tissue. An operational amplifier connected to a reference voltage and to the output side transistor drives the supply transistor to maintain the voltage at the output side transistor equal to the reference voltage. The at least one pair of transistors includes multiple pairs of transistors whose output side transistors drive respective electrodes with stimulation currents. The stimulator determines the initiation and duration of stimulation current pulses supplied to each electrode. At circuit activation, large currents are generated which discharge capacitances in the output side transistors causing rapid output side transistor turn on.

The invention discloses a relaxation oscillator for increasing frequency-control current linearity. The relaxation oscillator comprises a charge and discharge circuit, a control circuit and a floating charge and discharge capacitor arranged between the charge and discharge circuit and the control circuit. The control circuit detects voltage of the floating charge and discharge capacitor and outputs a control signal. The output signal of the oscillator is determined by only the charge process of the floating charge and discharge capacitor, so that complete-period delay of the oscillator is decreased and frequency-control current linearity of the oscillator is increased. The floating charge and discharge capacitor is formed by parallelly connecting two equal capacitors C1 and C2, and two pole plates of the capacitors C1 and C2 are cross-connected with each other; two ends of the floating charge and discharge capacitor are symmetrical, so that the influence of micro stray capacitance at two ends of the floating charge and discharge capacitor upon the output of the oscillator is decreased.

The invention provides a multi-input comparator comprising a first differential transistor, a second differential transistor, a first resistor and a second resistor, wherein the grid electrode of the first differential transistor is used as the first voltage input end of the multi-input comparator; the first voltage input end receives first voltage; the second differential transistor forming a differential transistor pair with the first differential transistor; the grid electrode of the second differential transistor is used as the second voltage input end of the multi-input comparator; the second voltage input end receives second voltage; one end of the first resistor is connected with the source electrode of the first differential transistor; one end of the second resistor is connected with the source electrode of the second differential transistor; the other end of the first resistor is connected with the other end of the second resistor, wherein a connected node of the first resistor and the first differential transistor is used as the current input end of the multi-input comparator and the current input end is connected with an injection current source; or the connected node of the second resistor and the second differential transistor is used as the current input end of the multi-input comparator, and the current input end is connected with an extraction current source.

The invention provides a relaxation oscillator. The relaxation oscillator comprises a biasing circuit, an oscillation circuit and a clock generation circuit, wherein the biasing circuit is used for producing biasing current and providing charging current for the oscillation circuit through the biasing current; the oscillation circuit is connected with the biasing circuit and is used for integrating the charging current by using a capacitor so as to produce integrator voltage; reset pulse is produced according to the integrator voltage and is input into the clock generation circuit; the clock generation circuit is connected with the oscillation circuit and is used for producing a clock signal through the reset pulse and controlling the switching of a switch in the oscillation circuit through the clock signal, so that the oscillation circuit can alternately charge or discharge. According to the relaxation oscillator, the frequency stability of the relaxation oscillator can be improved.

The invention provides a frequency dithering circuit and a frequency dithering method. The frequency dithering circuit comprises an oscillatory circuit, a decoding circuit and a delay circuit, wherein the oscillatory circuit generates an oscillatory frequency output signal; the oscillatory frequency output signal controls the decoding circuit to generate a plurality of pulse output signals; and the delay circuit generates a frequency dithering output signal when the oscillatory frequency output signal passes by the delay circuit; the frequency dithering output signal delays for a period of time compared with the oscillatory frequency output signal; and the pulse output signals control the delay time of the oscillatory frequency output signal. The invention applied in a switch power supply can reduce the EMI average noise of the switch power supply and has energy spectrum density planarization.

The invention provides a frequency jitter circuit, comprising an oscillating circuit, a decoding circuit, a level selecting circuit and a comparator circuit, wherein the oscillating circuit is used for generating a sawtooth signal; an oscillation frequency signal is input into the decoding circuit and controls the decoding circuit to generate a plurality of pulse signals; the pulse signals control the level selecting circuit to generate an output level signal which varies along with variation of a pulse output signal; the comparator circuit is used for comparing the sawtooth signal of the oscillation frequency and the output level signal and generating a frequency jitter signal; and the duty ratio of the frequency jitter signal and the edge of turn-on/turn-off vary along with variation of the output level signal. The invention also provides a method for generating frequency jitter. The frequency jitter circuit provided by the invention has the advantages of simple lines and easy realization. Meanwhile, frequency jitter ensures the switching frequency to be in a wide frequency range, ensures the EMI energy measured by EMI equipment to be diffused beyond the bandwidth, reduces the average EMI noises and flattens the energy spectrum density of the EMI noises.

The invention relates to an analogue signal generator for a TDI (Transport Driver Interface) CCD (Charge Coupled Device), which is used for generating analogue signals of output signals of the TDI CCD and overcoming the defect that the TDI CCD is not suitable for repeatedly testing in a process of debugging and developing a signal processing circuit of the TDI CCD. The analogue signal generator specially comprises a timing sequence generation circuit, a signal combination circuit, a filtering circuit and a power supply circuit. The timing sequence generation circuit generates a logic signal pulse, the analogue signals of the output signals of the TDI CCD are preliminarily obtained through the signal combination circuit, and then the analogue signals of the output signals of the TDI CCD are finally obtained after passing through the filtering circuit. According to the analogue signal generator for the TDI CCD provided by the invention, the analogue signals of the output signals of the TDI CCD under different integration time are simulated by adjusting the period of the analogue signals, so as to replace the output signals of the TDI CCD to be used for the development of the signal processing circuit of the TDI CCD.

The invention provides a frequency jittering circuit, which comprises a feedback voltage processing circuit, a differential triangular wave generating circuit, a differential converting single-end circuit and a voltage-controlled oscillator which are in circuit connection, wherein the input end of the feedback voltage processing circuit is connected with feedback voltage, and the output end of the feedback voltage processing circuit is connected with the differential triangular wave generating circuit, the differential converting single-end circuit and the voltage-controlled oscillator; the output end of the differential triangular wave generating circuit is connected with the differential converting single-end circuit the output end of which is connected with the voltage-controlled oscillator; and the output end of the voltage-controlled oscillator is connected with the differential triangular wave generating circuit, and is used for outputting a clock signal. The frequency jitteringcircuit has the advantages of good system stability and high frequency jittering accuracy.

A clock generator and data driver for a liquid crystal display device in which the clock generator includes a bias voltage supply receiving a power supply voltage and generating a bias voltage, an internal clock generator converting differential clock signals into an internal clock signal in response to the bias voltage, a bias line electrically connecting the bias voltage supply and the internal clock generator to supply the bias voltage to the internal clock generator, and a shield line shielding the bias line and receiving a voltage having a level identical with a level of the bias voltage.

A high frequency high voltage pulse generator is a pulse driving and emission source which is applied to fields of display measurement, display drive, communication technology and the like. The generator comprise a pulse signal amplification circuit, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) driving circuit, and a high voltage pulse output circuit which are in serial connection in order. An input terminal of the pulse signal amplification circuit is an input terminal of the generator, and an output terminal of the high voltage pulse output circuit is an output terminal of the generator. An upper end suspension power supply of the MOSFET driving circuit of the generator is formed by a high voltage pulse attenuator, so a positive/negative high frequency pulse which has a duty ratio of 0.005 % in a frame period and meets a technical index is generated in the display measurement, a maintenance pulse which has a duty ratio of 50% and satisfies more than 8 subfields is provided in the display drive, and an emission source pulse which 100% operating efficiency, large power and low loss is outputted in the communication technology.

A method comprises: receiving a differential input signal; converting the differential input signal into a first transmitted current and a second transmitted current using a common-source differential pair biased by a bias current; launching the first transmitted current and the second transmitted current onto a first port of a differential transmission line; receiving a first received current and a second received current from a second port of the differential transmission line; buffering the first received current and the second received current into a first output current and a second output current, respectively, using a current buffer, wherein the current buffer comprises: a common-gate amplifier pair, a first cross-coupling network configured to provide a negative feedback on the input side of the current buffer to reduce an input impedance of the current buffer, and a second cross-coupling network configured to provide a positive feedback on the output side of the current buffer to boost an output impedance of the current buffer; and terminating the first output current and the second output current with a load to establish a differential output signal.