Wallace Carolyn MatthewsRichardson, TX

6369576, Apr 9, 2002

Feb 3, 1997

08/794727

Wallace Edward Matthews - Richardson TX
David Louis Freeman - Plano TX
John Edward Landau - Mountain Lakes NJ

Texas Instruments Incorporated - Dallas TX

G01N 27416

324426, 320106, 320112, 320136

A battery charging system is provided which is comprised of a battery pack ( ) and a charging system ( ). The battery pack ( ) includes a battery ( ) and a battery capacity detect circuit ( ). The battery capacity detect circuit ( ) having a memory is interfaced with the charging system ( ) through a communication link to output a CHG-Bar signal. The battery capacity detect circuit ( ) is operable to perform numerous monitoring operations on the battery by detecting the charge input to the battery and detecting charge taken away from the battery in a discharge operation. This operation is performed independent of the charging operation by the charging system ( ). However, the charging operation of the charger ( ) can be affected with the CHG-Bar signal.

6577135, Jun 10, 2003

Apr 9, 2002

10/119385

Wallace Edward Matthews - Richardson TX
David Louis Freeman - Plano TX
John Edward Landau - Mountain Lakes NJ

Texas Instruments Incorporated - Dallas TX

G01N 27416

324426, 324427, 324428, 324429, 320106

A battery detect circuit ( ) is provided that is operable to dispose a sense resistor ( ) in series with the battery to determine whether the charge is being provided to the battery or being extracted from the battery. The voltage across the sensor resistor ( ) is sensed by a voltage/frequency converter ( ). The voltage/frequency converter ( ) is a differential structure comprised of two integrator structures ( ) and ( ) that are operable to utilize a switched capacitor configuration to drive comparators on the output thereof. Each of the integrator structures ( ) and ( ) has associated therewith passive elements and active elements. The integrators ( ) and ( ) have associated therewith integration capacitors ( ) and ( ). Additionally, there are two operational amplifiers ( ) and ( ) that provide the active components of each of the integrators ( ) and ( ). The various switched capacitor circuits ( ) and ( ) associated with the amplifiers ( ) and ( ) are provided to provide the integration operation.

6107802, Aug 22, 2000

Oct 19, 1998

9/174693

Wallace Edward Matthews - Richardson TX
David Louis Freeman - Plano TX
John Edward Landau - Mountain Lakes NJ

G01N 27416
G01R 3136

324427

A battery charging system is provided which is comprised of a battery pack (30) and a charging system (20). The battery pack (30) includes a battery (10) and a battery capacity detect circuit (32). The battery capacity detect circuit (32) is interfaced with the charging system (20) through a single line to output a CHG-Bar signal. The battery capacity detect circuit (32) is operable to perform numerous monitoring operations on the battery by detecting the charge input to the battery and detecting charge taken away from the battery in a discharge operation. This operation is performed independent of the charging operation by the charging system (20). However, the charging operation of the charger (22) can be affected with the CHG-Bar signal.

5426386, Jun 20, 1995

Apr 21, 1992

7/871385

Wallace E. Matthews - Richardson TX
Gene L. Armstrong - Garland TX

Benchmarq Microelectronics, Inc. - Carrollton TX

H03K 524

327 63

The low power voltage comparator with hysteresis includes a comparator (10) that is operable to receive the output from a battery (14) on the positive input thereof and the output of a battery (16) on the negative input thereof. An offset circuit (22) is provided in series with the voltage of the battery (14) and the comparator (10), and an offset circuit (24) is provided between the battery (16) and the comparator (10). The offset circuits (22) and (24) are adjustable by a hysteresis control circuit (26) to offset the voltage thereof for the non-selected battery to be higher than that for the selected battery such that the voltage drop across the offset for the non-selected battery is greater than that for the selected battery. When the voltage on the selected battery falls below the offset voltage of the non-selected battery, the hysteresis control then decreases the offset upon selecting the other battery and increases the offset or the battery that is deselected. The offset circuits (22) and (24) each comprise primary resistive elements (26) and (36) which are connected through a current sink (50) to ground.

5617040, Apr 1, 1997

Dec 19, 1995

8/575096

Wallace E. Matthews - Richardson TX

Benchmarq Microelectronics, Inc. - Dallas TX

H03K 19177

326 38

An integrated circuit with programmable output drive/program pins includes a plurality of output pads (30) which are each operable to interface with a separate and dedicated output driver (38). The output driver (38) is operable to drive an LED output device (14) in an operating mode. In a program mode, the driver (38) is disabled and a program buffer (40) enabled. At the same time, the LED output device (14) is disabled such that no impedance is presented to the output pad (30) due to operation of the LED output device (14). A programming resistor (18) is disposed between the pad (30) and one of three program reference voltages. A first program state is represented when the resistor (18) is tied to ground, a second program state is represented when the resistor (18) is tied to an open circuit and a third program state is represented when the resistor (18) is tied to a positive voltage. The program buffer (40) senses the presence of the resistor and what voltage it is tied to by either sinking current to the pad (30) or sourcing current therefrom. Therefore, the resistor (18) can be disposed on the pad (30) during operation and a power on reset or any type of external reset controlling a CPU (46) to initiate the program operation.

5859560, Jan 12, 1999

Feb 18, 1997

8/801559

Wallace Edward Matthews - Richardson TX

Benchmarq Microelectroanics, Inc. - Dallas TX

H01L 3100

327513

A temperature compensated current source for driving a multi-vibrator (19) includes a voltage generator (10) that outputs a voltage that is proportional to absolute temperature (PTAT) and a resistor (12) for setting the current output by the voltage generator (10). The temperature coefficient of the resistor (12) is chosen such that any variations in the current supplied by the voltage generator (10) are compensated for to result in a current that has substantially no temperature variation. This current is mirrored to a current source (18) for driving the multi-vibrator (19). The voltage across the resistor (12) is a function of temperature, with the current being a function of the value of the resistor (12). The temperature coefficient of the resistor (12) is substantially equal to the temperature coefficient of the voltage generator (10) to yield a temperature coefficient of substantially 0 ppm/. degree. C. for the current.

5357203, Oct 18, 1994

Jul 8, 1992

7/910685

John E. Landau - Dallas TX
Wallace E. Matthews - Richardson TX
David L. Freeman - Plano TX

Benchmarq Microelectronics, Inc. - Carrollton TX

H02J 704
G01N 27416
G01R 3136

324427

A battery detect circuit (32) is connected to the battery with the current input to the battery and extracted from the battery measured with a sense resistor (50) and then converted to charge and discharge pulses with a V/F converter (52). A microcontroller (64) is operable to increment a Nominal Available Charge (NAC) register (180) during a charge operation, and to increment a Discharge Count Register (DCR) (184) during a discharge operation. The NAC register (180) indicates the available charge, which value is output to a display (34). The maximum value to which the NAC value can rise is limited by a value stored in the last measured discharge register (182). This value represents the value stored in the DCR (184) whenever the battery is discharged from an apparent full state to a fully discharged state. This results in a qualified transfer to the LMD register (182) such that no knowledge of the actual battery charge is necessary. The microcontroller (64) is operable to determine the rate of discharge corresponding to the voltage across the sense resistor (50).

5187396, Feb 16, 1993

May 22, 1991

7/704068

Gene L. Armstrong - Garland TX
Wallace E. Matthews - Richardson TX

Benchmarq Microelectronics, Inc. - Carrollton TX

H03K 522
H03K 301

307494

A differential comparator is provided for controlling two switches (40) and (42) to switch two supplies (10) and (12), respectively, to a common output node (22). The decision/control circuit (44) outputs two control signals (46) and (48), the logic state thereof being a function of whether supply (10) is higher than supply (12) or supply (12) is higher than supply (10). The operating power for the decision/control circuit (44) is derived from the supplies (10) and (12), and not from the common output node (22), such that when the switches (40) and (42) are closed and no power is being supplied by either of the supplies (10) and (12), the decision/control circuit (44) has sufficient power to make a decision.