Patents by Inventor Arthur H. M. Van Roermund

Arthur H. M. Van Roermund has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7466252
    Abstract: A method and apparatus for the calibration of current cells, whereby a current signal from each current cell may be generated by either a thermometer current cell, or a binary current cell. If generated by a binary current cell, then two or more replica binary current cells exist to form a group of binary current cells within two or more binary current cell sets. The current magnitude generated by each replica current cell of each binary current cell group is first calibrated to be substantially equal to each other. Next, the combined current generated by the replica current cell group is calibrated to be substantially equal to a magnitude of a temporary current signal, or a portion thereof. Subsequent less-significant binary current cell groups are similarly calibrated to the temporary current signal through the use of the previously calibrated, more-significant binary current cell groups.
    Type: Grant
    Filed: July 12, 2007
    Date of Patent: December 16, 2008
    Assignee: Xilinx, Inc.
    Inventors: Georgi I. Radulov, Patrick J. Quinn, Johannes A. Hegt, Arthur H. M. van Roermund
  • Patent number: 7076384
    Abstract: A method and apparatus for calibrating a current source to a reference current through the use of 1-bit current comparisons. A temporary current source is first calibrated to the reference current, which allows an input offset current generated by the current comparator to be memorized. The current to be calibrated is then fine-tuned to the temporary current within specified limits, which effectively cancels comparison error that is generated by the input offset current.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: July 11, 2006
    Assignee: Xilinx, Inc.
    Inventors: Georgi I Radulov, Patrick J. Quinn, Johannes A. Hegt, Arthur H. M. van Roermund
  • Patent number: 5373243
    Abstract: An impedance transformation circuit for transforming a two-pole electrical impedance (Z) includes a first controllable current source for producing a current (I.sub.1) flowing through the impedance during operation. An operational amplifier is coupled to the first current source for providing a control signal (V.sub.0) corresponding to the impedance current (I.sub.1). A second controllable current source is coupled to the operational amplifier for providing at an input terminal of the circuit a further current (I.sub.2) proportional to the impedance current (I.sub.1) as a function of the control signal (V.sub.0). As a result of using a first and second controllable current source and applying the control signal delivered by the operational amplifier to the control inputs of the two current sources, an impedance transformation is obtained which is dependent on similar parameter ratios. The circuit is suitable for use as an integrated semiconductor circuit.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: December 13, 1994
    Assignee: U.S. Philips Corporation
    Inventors: Arthur H. M. Van Roermund, Johan H. I. Hendrickx
  • Patent number: 4987580
    Abstract: The invention relates to a semiconductor device including a charge transfer device having an output stage (8). The output stage (8) has a read-out zone (9), a feedback capacitor (11) and an amplifier (10). An inverting input (15) of the amplifier (10) is connected to the read-out zone (9) and an output (16) of the amplifier (10) is fed back via the feedback capacitor (11) to the inverting input (15). According to the invention, the capacitor (11) is a capacitor of the MOS type and means are provided by which during operation of the charge transfer device the surface potential of a surface region (13) in the capacitor (11) is solely determined by the potential of the read-out zone (9). Consequently, the capacitance of the feedback capacitor (11) is dependent upon the potential across it, as a result of which there is a linear relation between the charge supplied to the read-out zone (9) and the voltage variation across the capacitor (11 ).
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: January 22, 1991
    Assignee: U.S. Philips Corp.
    Inventors: Marcellinus J. M. Pelgrom, Antonius J. G. Jochijms, Arthur H. M. Van Roermund
  • Patent number: 4965711
    Abstract: A switched capacitor network includes an input terminal (2) an output terminal (2), a series arrangement of a first and a second switching transistor, each having a control electrode (S.sub.1) for receiving a first (S.sub.1 ) and a second switching signal, respectively, and a capacitance between the junction point of the two switching transistors and a point of constant potential. The two switching transistors have a zone in common and the capacitance (S.sub.s) is exclusively constituted by the parasitic capacitance of the zone (17). This structure results in a switched capacitor network with an increased time constant.
    Type: Grant
    Filed: March 27, 1990
    Date of Patent: October 23, 1990
    Assignee: U.S. Philips Corp.
    Inventors: Petrus J. M. Kamp, Arthur H. M. Van Roermund
  • Patent number: 4860354
    Abstract: Arrangement for decoding a stereo multiplex signal, having a baseband stero signal (L+R), a stereo difference signal (L-R) which is amplitude-modulated on a suppressed sub-carrier, and a pilot signal having a frequency located between the frequency bands of the two signals, the arrangement having an input for the stereo multiplex signal and left and right stereo signal outputs, the input being coupled both, via a pilot selection circuit, to a phase-locked loop for regenerating the sub-carrier and to a multiplier circuit for multiplying at least the modulated stereo difference signal by the regenerated sub-carrier. In order to improve the stereo channel separation, the pilot selection circuit includes a bandpass filter of the switched capacitor type, a clock input of which is coupled to an output of an voltage-controlled oscillator incorporated in the loop.
    Type: Grant
    Filed: November 30, 1987
    Date of Patent: August 22, 1989
    Assignee: U. S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4716375
    Abstract: A switched-capacitor multiplier circuit for multiplying an information signal x(t) by a bipolar carrier signal d(t) consisting of a distributed multiplier circuit with which the bipolar carrier signal is normally associated. To reduce offset voltages in the output signal caused by the operational amplifiers used and caused as a result of clock feed-through, it is not the bipolar carrier signal itself, but a full-wave rectified version thereof that is associated with the distributed multiplier circuit. The output signal of the multiplier circuit is applied to an auxiliary multiplier circuit multiplying it by +1 or -1 dependent on the instantaneous polarity of the bipolar carrier signal d(t). The offset voltage is thereby transposed to a frequency which is at least equal to the fundamental frequency of the carrier signal so that, if desired, it can be suppressed with the aid of a suitably chosen low-pass filter without the desired signal being affected thereby.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: December 29, 1987
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4692737
    Abstract: A time-discrete amplitude-continuous or a time-discrete amplitude-discrete signal is converted in to a 1-bit encoded signal by means of a quantizer, the quantization-error signal being fed back via a loop filter. The transfer function of the loop filter is given by H(Z)=1-(Z-b).sup.n /(Z-a).sup.n, where n.gtoreq.3, b.perspectiveto.1 and 0<a<b. In order to preclude, the input signal of the loop filter is limited by a limiter.
    Type: Grant
    Filed: October 17, 1986
    Date of Patent: September 8, 1987
    Assignee: U.S. Philips Corporation
    Inventors: Eduard F. Stikvoort, Arthur H. M. van Roermund, Peter J. A. Naus
  • Patent number: 4691171
    Abstract: A first resistor (R.sub.1) and a first capacitor (C.sub.1) constitute a filter arrangement having a time constant which is not very accurate due to the inaccuracy of the resistor and the capacitor values in integrated circuits. The time constant is adjusted using a circuit comprising a reference resistor (R.sub.2) and a switched capacitor (C.sub.3). The value of the reference resistor (R.sub.2) and the equivalent resistance of the switched capacitor (C.sub.3) are compared by means of an integrator (C.sub.2, 2) from whose output (9) a control voltage is taken via a hold circuit (C.sub.4, C.sub.5). The control voltage is equal to the voltage at that point on the reference resistor where the resistance value is equal to that of the switched capacitor (C.sub.3). By means of comparators (21 to 30) and switches (S.sub.11 to S.sub.20) a percentage of the total resitance of the first resistor (R.sub.1) is short-circuited. This percentage is equal to the difference between the resistance of the reference resistor (R.
    Type: Grant
    Filed: April 29, 1985
    Date of Patent: September 1, 1987
    Assignee: U.S. Philips Corporation
    Inventors: Arthur H. M. Van Roermund, Petrus M. C. Coppelmans
  • Patent number: 4616185
    Abstract: Multiplying circuit for multiplying a first signal x(t) by a periodic second signal y(t) and being particularly suitable for use as an amplitude demodulator in a stereo decoder or in a phase-locked loop. It comprises N signal channels 26(k) wherein k=0, 1, . . . n-1, each receiving the first signal x(t) and each producing a channel signal. Each signal channel is formed by, arranged in cascade, a switched-capacitor circuit 28(k;1), 28(k;2), 29(k), the circuit included in the signal channel being controlled by a train of control pulses g(k,i) which each have a finite duration and occur with a repetition period T.sub.o and at instants t.sub.o +k(T.sub.o /N)+iT.sub.o where i= . . . -2, -1, 0, 1, 2, 3, . . . , means 29(k), 31, 30 for multiplying the amplitude of the signal x(t) by a constant weighting factor W(k) which is equal to y(t.sub.o +k(T.sub.o /N), pulse-reshaping means 29(k), 30, 31 for converting a pulse applied thereto into a pulse having a predetermined duration.
    Type: Grant
    Filed: June 13, 1984
    Date of Patent: October 7, 1986
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4616192
    Abstract: A phase-locked loop has a phase detector and a clock pulse oscillator. The phase detector multiplies a received reference signal by a comparison signal. It is constituted by a plurality of signal channels 207 each receiving the reference signal and having a cascade arrangement of a switching circuit 208 and a weighting network 209. The switching circuit is controlled by one or more sequences of main control pulses supplied by a pulse distributor circuit receiving clock pulses. Each signal channel has a constant weighting factor. For the k.sup.th signal channel the weighting factor is equal to the signal sample n(t.sub.o +kT.sub.s) of a fundamental signal n(t) which has a fundamental frequency f.sub.o. T.sub.s is the reciprocal of the clock pulse frequency f.sub.s. For each sequence of main control pulses controlling the switching circuit in the k.sup.th signal channel, this signal channel produces a main signal z(k, t). The main signals supplied by all the signal channels are added together.
    Type: Grant
    Filed: April 12, 1985
    Date of Patent: October 7, 1986
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4569072
    Abstract: A clock-controlled filtering arrangement for suppressing a number of interference frequencies related to a clock frequency, which comprises a time-discrete comb filter included in a negative feedback loop for a selective negative feedback of the said interference frequencies, which time-discrete comb filter is connected to an output of a clock generator for controlling the frequency location of the pass ranges of the comb filter. In order to avoid on the one hand the introduction of quantizing noise and the use of additional circuits, such as A/D and D/A converters, and on the other hand the occurrence of error cumulation while maintaining an adequate interference suppression, the time-discrete comb filter is of the switched capacitor N-path filter type.
    Type: Grant
    Filed: November 21, 1983
    Date of Patent: February 4, 1986
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4518935
    Abstract: Band-rejection filter of the switched capacitor type in which at least one unwanted frequency component present in an information signal must be suppressed. To that end this filter comprises and adding circuit 4 to which the information signal is applied via a switching device 3 and a feedback signal via a switching device 5. Both switching devices are controlled by a first control signal consisting of a sequence of control signal periods of a duration T.sub.s which are each divided into a tracking phase and into an interrupt phase. During the tracking phase the signal can pass uninterruptedly through the switching device, while during the interrupt phase signals are not allowed to pass. The output of adding circuit 4 is coupled inter alia via a switching device 8 to the input of a bandpass filter 9 whose passband at least coincides with the unwanted frequency component.
    Type: Grant
    Filed: September 26, 1983
    Date of Patent: May 21, 1985
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4517655
    Abstract: Multiplier circuit for multiplying an information signal x(t) by a periodic signal y(t) having frequency f.sub.o, more specifically for amplitude modulation purposes in a stereo decoder. The multiplier circuit comprises N switching circuits 21(k) wherein k=0, 1, . . . N-1 which are each connected to a clock pulse generator 221, 222 by means of a control channel 25(k) and are each connected to an input of an adder device 28 by means of a signal channel 26(k). In addition, each switching circuit 21(k) receives the information signal x(t). A series of clock pulses g(k;t) is applied to each control channel in such a manner that for the control channel having number k these clock pulses occur at the instants t.sub.o +k(T.sub.o /N)+iT.sub.o wherein t.sub.o represents a constant T.sub.o =1/f.sub.o and i=. . . , -2, -1, 0, 1, 2, . . . Each signal channel 26(k) comprises a weighting network 27(k) having a constant weighting factor W(k) defined by the relation W(k)=y(t.sub.o +k(T.sub.o /N)).
    Type: Grant
    Filed: September 10, 1982
    Date of Patent: May 14, 1985
    Assignee: U.S. Philips Corporation
    Inventors: Theodoor A. C. M. Claasen, Albert J. Stienstra, Arthur H. M. van Roermund
  • Patent number: 4502019
    Abstract: A dynamic amplifier circuit, specifically for switched-capacitor filters, having a current source which supplies an exponentially-decreasing bias current. In addition, a current source is included for supplying an additional bias current in order to define the minimum bias current in the amplifier circuit.
    Type: Grant
    Filed: December 10, 1982
    Date of Patent: February 26, 1985
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. Van Roermund
  • Patent number: 4455666
    Abstract: Charge transfer devices exhibit transfer inefficiencies, so that a part of a transferred charge packet is left and lags the original charge packet. This results in "smearing" of the original charge packet, thereby adversely affecting the unit-function response and the frequency response of the charge transfer device. The invention provides a solution to this problem, utilizing a compensation charge derived from the original charge packet, which at a suitable instant is applied to a point where the residual charge is cancelled via a feedback loop.
    Type: Grant
    Filed: April 19, 1982
    Date of Patent: June 19, 1984
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4443885
    Abstract: A method and device in which both positive and negative signal charges can be transferred from a first capacitance to a first point via a transistor circuit which exhibits a threshold level. For this purpose the first capacitance contains a reference charge with a positive or a negative polarity. First, the voltage on the first point is switched so that the first capcitance is charged from said first point and subsequently so that the first capcitance discharges towards the first point to its reference charge, which corresponds to said threshold level, in such a way that the net charge transfer from the first capacitance to the first point is equal to the positive or negative signal charge and the charge on the first capacitance is restored to a reference level.
    Type: Grant
    Filed: September 28, 1982
    Date of Patent: April 17, 1984
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. van Roermund
  • Patent number: 4428070
    Abstract: A dynamic circulation memory is provided comprising a charge transfer device with surplus-value storage and an adaptive refreshing circuit for maximum information storage. Reference-charge packets are passed through the charge transfer device together with the signal-charge packets, so that signal distortion caused by the charge transfer device and its interface is compensated for.
    Type: Grant
    Filed: June 24, 1980
    Date of Patent: January 24, 1984
    Assignee: U.S. Philips Corporation
    Inventors: Arthur H. M. van Roermund, Petrus M. C. Coppelmans
  • Patent number: 4266146
    Abstract: A charge transfer device having one or more control electrodes connected to switching means so that the electrode can perform two functions. Normally the electrode is used for charge transfer but it may be switched to act as a blocking electrode for blocking the charge present underneath it for one or more clock phases. This permits the device to be formed as a filter, an analog-to-digital converter or digital-to-analog converter in a simple and inexpensive manner. The charge transfer channel may be split into sections using isolation diffusions.
    Type: Grant
    Filed: October 3, 1978
    Date of Patent: May 5, 1981
    Assignee: U.S. Philips Corporation
    Inventor: Arthur H. M. Van Roermund