Stephen R Kelley

US Patent:

20020021804, Feb 21, 2002

Filed:

Feb 16, 2001

Appl. No.:

09/785772

Inventors:

Robert Ledzius - Austin TX, US
Stephen Kelley - Austin TX, US

International Classification:

H04L009/00
H04L009/32
G06F011/30

US Classification:

380/044000, 380/045000, 380/281000, 380/283000, 713/161000, 713/168000, 713/170000, 713/171000, 713/200000, 713/201000

Abstract:

A system and method of private, three-key data encryption, secure storage, secure transmission and decryption is disclosed. The system is comprised of three core components, including a data server, a user device and a security server. The data server and user device have private security keys associated therewith. A third key is generated at the security server. The third key is transmitted to the data server and user device in encrypted form, using the data server security key to encrypt the third key as it is transmitted to the data server, and the user device security key to encrypt the third key as it is transmitted to the user device. As a result, a secure data transmission session may be established.

US Patent:

44320892, Feb 14, 1984

Filed:

Dec 24, 1981

Appl. No.:

6/334412

Inventors:

Henry Wurzburg - Round Rock TX
Stephen H. Kelley - Austin TX

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04J 300
H04M 906

US Classification:

3701101

Abstract:

In a digital telephone system, a digital private automatic branch exchange (PABX) has a plurality of digital line cards for coupling the PABX to respective digital subscriber sets via subscriber lines. In each digital line card, a digital loop transceiver operates in a master mode to couple the digital data bus of the PABX to the subscriber line via a subscriber line interface circuit in response to control signals provided by the PABX on the control bus thereof. In each digital subscriber set, a digital loop transceiver operates in a slave mode to couple the subscriber set to the subscriber line via a subscriber line interface circuit and to provide the several control signals required by the other components thereof. The digital loop transceivers provide communication on each of two communication channels, with the digital data words of the first channel being treated the same as the digital data words of the second channel.

US Patent:

62048341, Mar 20, 2001

Filed:

Aug 17, 1994

Appl. No.:

8/292135

Inventors:

Robert C. Baker - Austin TX
William J. Donoghue - Round Rock TX
Stephen H. Kelley - Austin TX
Claude Hilbert - Austin TX

Assignee:

SI Diamond Technology, Inc. - Austin TX

International Classification:

G09G 332

US Classification:

345 74

Abstract:

A system and method for producing uniform energy dissipation in display pixels with widely varying electrical characteristics in order to equalize light output and improve yield within a matrix addressable display panel. The present invention is implemented within a driver circuit utilizing the concept of current integration. A reference voltage, which is proportional to the most efficient pixel within the display is compared to the energy dissipated within a particular pixel during illumination of that pixel. A current mirror circuit supplies a current equivalent to the current provided to the object pixel to an integrator circuit resulting in a rising voltage within the integrator circuit. The rising voltage is proportional to the energy being dissipated within the current pixel. Once the rising voltage is equal to or greater than the reference voltage, current is removed from the object pixel.

US Patent:

43842763, May 17, 1983

Filed:

May 8, 1981

Appl. No.:

6/261850

Inventors:

Stephen H. Kelley - Austin TX
Richard W. Ulmer - Austin TX

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03K 1302

US Classification:

340347DA

Abstract:

An operational amplifier capable of selectively performing a variety of circuit functions is provided. A single operational amplifier utilizes switched capacitors for sampling and holding an input signal, for establishing a low frequency pole, for applying the sample to an output capacitance to charge the capacitance and for comparing the input signal with a reference. The multi-function circuit provides a large savings in circuit area and permits versatility of circuit applications. One embodiment of the invention is to utilize a companding DAC having a capacitor array which may be used as the output capacitance of the operational amplifier circuit. The DAC provided utilizes an R ladder DAC coupled directly to a C DAC and has a switching structure that is simpler than comparable prior art circuits. The DAC is asynchronous and has programmable A- and Mu-255 law PCM conversion capability. Coupled directly to the C DAC is an operational amplifier receive filter circuit which utilizes the C DAC as an input capacitor thereby eliminating the need for a buffer amplifier and allowing the DAC to be used for both analog to digital and digital to analog conversion.

US Patent:

43706320, Jan 25, 1983

Filed:

May 8, 1981

Appl. No.:

6/261848

Inventors:

Robert N. Allgood - Austin TX
Stephen H. Kelley - Austin TX
Richard W. Ulmer - Austin TX
Henry Wurzburg - Round Rock TX

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03H 1112
H03F 134

US Classification:

333173

Abstract:

An operational amplifier capable of selectively performing a variety of circuit functions is provided. A single operational amplifier utilizes switched capacitors for sampling and holding an input signal, for establishing a low frequency pole, for applying the sample to an output capacitance to charge the capacitance and for comparing the input signal with a reference. The multi-function circuit provides a large savings in circuit area and permits versatility of circuit applications. One embodiment of the invention is to utilize a companding DAC having a capacitor array which may be used as the output capacitance of the operational amplifier circuit. The DAC provided utilizes an R ladder DAC coupled directly to a C DAC and has a switching structure that is simpler than comparable prior art circuits. The DAC is asynchronous and has programmable A-and Mu-255 law PCM conversion capability. Coupled directly to the C DAC is an operational amplifier receive filter circuit which utilizes the C DAC as an input capacitor thereby eliminating the need for a buffer amplifier and allowing the DAC to be used for both analog to digital and digital to analog conversion.

US Patent:

46188525, Oct 21, 1986

Filed:

Feb 27, 1985

Appl. No.:

6/706208

Inventors:

Stephen H. Kelley - Austin TX
Mathew A. Rybicki - Austin TX

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03K 1308

US Classification:

340347AD

Abstract:

An N bit converter, where N is an integer, is provided for effecting A/D and D/A conversions by utilizing a capacitor array and a resistor voltage divider string. The converter may be linear or nonlinear and the structure remains monotonic independent of the accuracy of the converter. Although monotonic, device count is minimized and only 2. sup. (N/2) stages are required to implement an N bit linear converter. Reduction of the number of circuit elements is achieved, in part, by shared use of decode circuitry for the most significant and least significant bits of the N bits.

US Patent:

41515170, Apr 24, 1979

Filed:

Feb 14, 1977

Appl. No.:

5/768117

Inventors:

Stephen H. Kelley - Tempe AZ

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03K 1322

US Classification:

340347C

Abstract:

A monolithic integrated circuit encoder/decoder capable of converting an analog signal to a digital signal and capable of reconstructing an analog signal from a digital signal employing continuously variable slope delta modulation. The dynamic range of the continuous variable slope delta modulation is increased by employing means for providing a companding ratio reference coupled to a means for comparing the companding ratio reference against a filtered coincidence output from the encoder/decoder and then amplifying any difference therebetween. The difference is used to control the gain of the continuously variable slope delta modulator and can be used to modify the companding ratio reference to provide a closed-loop controlled companding ratio for the encoder/decoder.

US Patent:

43205194, Mar 16, 1982

Filed:

Apr 10, 1980

Appl. No.:

6/138969

Inventors:

Stephen H. Kelley - Austin TX
Henry Wurzburg - Tempe AZ

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03K 1332

US Classification:

375 26

Abstract:

A sampled data system having improved (sin X)/X correction is provided. A modified switched capacitor filter is used as a receive filter. The switched capacitor filter is modified in a manner to provide a charge gain thereby avoiding the increase in thermal noise normally associated with voltage gain amplification. The modified switched capacitor filter does not impair the dynamic range of the system and can be made duty cycle independent by providing additional controllable switches to the filter.