31
Bruce D Signore, Eric J Swanson: Method and apparatus for calibration of a monolithic voltage reference. Crystal Semiconductor Corporation, Gregory M Howison, August 8, 1995: US05440305 (97 worldwide citation)

A method and apparatus for calibration of errors in a monolithic reference includes a bandgap voltage reference (50) that outputs an untrimmed voltage and a temperature voltage. The untrimmed voltage and temperature voltage are input to a delta-sigma A/D converter (52) which has the output thereof p ...


32
Thomas Ying Ching Lo, Yuh Show Tsai: EKG based heart rate monitor with digital filter and enhancement signal processor. Salutron, Townsend and Townsend and Crew, March 2, 1999: US05876350 (95 worldwide citation)

A convenient low-cost heart rate monitor. In one embodiment, a digital filter structure includes a low pass filter having a notch at 60 Hz and a bandpass filter which amplifies signals in a frequency range from 10-40 Hz and has a notch at 60 Hz. This digital filter has a recursive structure and uses ...


33
Adrian B Early, Larry L Harris, Michael J Callahan Jr: Digitally calibrated delta-sigma analog-to-digital converter. Crystal Semiconductor, Gregory M Howison, July 24, 1990: US04943807 (95 worldwide citation)

A self-calibrated analog-to-digital converter with a corrected output includes an analog modulator (18) for receiving an analog input voltage and outputting a pulse train having a value proportional to the analog input voltage. The pulse train is filtered by a digital filter (20) which has the outpu ...


34
Bernd Prohaska, Hans Dieter Schwartz, Rudolf Winkelmann, Gerhard Zettl: Digital filter switch for data receiver. Siemens Aktiengesellschaft, Hill Van Santen Steadman & Simpson, February 16, 1988: US04726041 (93 worldwide citation)

A digital filter switch for use with a data receiver incorporates first and second squaring units connected to the outputs of first and second band-pass filters tuned to the separation and character frequencies in a signal transmission. The outputs of the squaring units are interconnected via an add ...


35
Philippe Sehier, Cyril Bertrand: Multirate receive device and method using a single adaptive interpolation filter. Alcatel, Sughrue Mion Zinn Macpeak & Seas PLLC, August 3, 1999: US05933467 (92 worldwide citation)

A device for receiving a source digital signal transmitted at one or more source symbol frequencies F.sub.s samples a received analog signal transposed into the baseband and delivers an entirely demodulated sample signal. The sampling frequency F.sub.e complies with the generalized sampling conditio ...


36
Xiao Y Guo, Gerard Maral: Digital filter-type frequency demultiplexing device. France Telecom, Lowe Price LeBlanc & Becker, March 29, 1994: US05299192 (89 worldwide citation)

After sampling a multicarrier signal, groups of multiplex modulated carriers with identical bandwidths are separated by group filters. Clock frequencies of the carriers are then reduced by decimators depending on their respective bandwidths. To separate each of the modulated carriers in each of the ...


37
Kenichi Terai, Hiroyuki Hashimoto, Isao Kakuhari: Noise control system. Matsushita Electric Industrial, Ratner & Prestia, July 9, 2002: US06418228 (88 worldwide citation)

A noise control system includes: a control sound generator for generating a control sound; an error detector for detecting an error signal between the control sound and noise; a noise detector for detecting a noise source signal; an adaptive filter for outputting a control signal; and a coefficient ...


38
Hirotake Wakai, Makoto Ohnishi, Fumihito Tomaru: Digital modulator having a digital filter including low-speed circuit components. Hitachi Denshi Kabushiki Kaisha, Antonelli Terry Stout & Kraus, July 20, 1999: US05926065 (88 worldwide citation)

A digital demodulator which demodulates an analog signal obtained through a quadrature amplitude modulation to produce a digital demodulated signal includes a converter to convert the analog signal into a digital signal and a signal processor to quadrature-demodulating the digital signal from the co ...


39
Mohammad Rez Karim, Robert Louis Cupo, Mohsen Sarraf, Mohammad Zarrabizadeh: Fast frame synchronization. Agere Systems, Istrate Ionescu, December 31, 2002: US06501810 (88 worldwide citation)

A receiver for receiving synchronized digital transmissions organized in frames, each frame having a frame start, has a clock for generating pulses at time intervals with respect to a time reference and a counter for generating a count of the time intervals with respect to the time reference. A/D co ...


40
Masao Noro, Yusuke Yamamoto, Toshio Maejima: CMOS differential amplifier for a delta sigma modulator applicable for an analog-to-digital converter. Yamaha Corporation, Graham & James, January 25, 2000: US06018262 (85 worldwide citation)

An analog-digital converter includes a .DELTA..SIGMA. modulator, a digital filter, a high-pass filter and a multiplier which are connected in series. Analog input is converted into serial-bit strings by the .DELTA..SIGMA. modulator, for which gain `1/A` is set. The digital filter extracts low-freque ...



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