Mark L Morgan

US Patent:

6411126, Jun 25, 2002

Filed:

Dec 21, 2000

Appl. No.:

09/747271

Inventors:

Steven J. Tinsley - Garland TX
Julie Hwang - Richardson TX
Mark W. Morgan - Allen TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03K 1908

US Classification:

326 83, 326 30, 326115

Abstract:

The output slew rate of a differential transmission line driver ( ) can be limited by suitably controlling signal slew rates ( ) at the control inputs (neg, pos) of the drive switches (M -M ) that control current flow through the load impedance (Rload) of the driver.

US Patent:

6437622, Aug 20, 2002

Filed:

Mar 27, 2001

Appl. No.:

09/818111

Inventors:

Steven J. Tinsley - Garland TX
Julie Hwang - Richardson TX
Mark W. Morgan - Allen TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03K 513

US Classification:

327175, 327513, 327530

Abstract:

The present invention provides improved slew rate control over a varied operating temperature range. A switching device (P , N ) receives from a predrive circuit ( ) a control signal that limits a slew rate of the switching devices output and also varies proportionally to the operating temperature. In this manner, the effect of temperature on the slew rate can be reduced.

US Patent:

6480029, Nov 12, 2002

Filed:

Jun 26, 2001

Appl. No.:

09/891904

Inventors:

Mark W. Morgan - Allen TX
Fernando D. Carvajal - Fairview TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03K 1902

US Classification:

326 56, 326 17

Abstract:

A low voltage 485-driver circuit that meets the standard leakage and 1. 5 voltage differential output requirements of the TIA/EIA-485 specification while operating from a 3V supply. The circuit avoids the voltage drop across the series Schottky diodes in the output driver of a conventional 485-driver by moving the Schottky blocking diodes from the output stage signal path to the pre-driver stage so that the output stage is restricted to back-gate biasing only. In addition, the circuit uses stacked NMOS transistors to maintain lower voltage across each NMOS transistor in order to prevent hot-carrier injection. This allows lower voltage rated output NMOS transistors to be used, resulting in higher speed operation. The circuit will withstand excessive common mode voltages in the range of +12V to -7V applied to the output while in either signaling ON state or the disabled OFF state.

US Patent:

6628150, Sep 30, 2003

Filed:

Apr 2, 2002

Appl. No.:

10/114516

Inventors:

Fernando D. Carvajal - Fairview TX
Mark W. Morgan - Allen TX
Srikanth Gondi - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03K 300

US Classification:

327108, 327 65, 327374

Abstract:

Transitions (e. g. high to low and/or low to high) associated with operation of the driver are employed to implement control, which can be applied as a pulse in response to an occurrence of the transition. The control operates to speed up the transition at the output of the driver, such as can reduce driver switching times and enable a corresponding increase in data transmission rates.

US Patent:

6661288, Dec 9, 2003

Filed:

Feb 9, 2002

Appl. No.:

10/072862

Inventors:

Mark Morgan - Allen TX
Srikanth Gondi - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03F 345

US Classification:

330258, 330259, 330260, 330261, 330296, 330297, 330 9

Abstract:

An apparatus for effecting high speed switching of a communication signal between a first component and a second component includes: (a) a switching circuit configured for receiving the signal from the first component that includes a plurality of switch elements responding to the signal to produce an interim signal that is substantially a model of the signal; (b) a follower circuit having an input locus coupled with the switching circuit for receiving the interim signal; the follower circuit has an output locus configured for presenting an output signal that is substantially duplicating the interim signal; and (c) a control circuit coupling the follower circuit with the switching circuit and receives a feedback signal from the follower circuit representative of the output signal; the control circuit responds to the feedback signal to effect operation of the switching circuit to control at least one first parameter relating to the interim signal.

US Patent:

6744280, Jun 1, 2004

Filed:

May 9, 2002

Appl. No.:

10/143299

Inventors:

Mark W. Morgan - Allen TX
Fernando D. Carvajal - Fairview TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03K 1716

US Classification:

326 86, 326 83, 326 30, 327321, 327513, 327378, 327108, 327 87

Abstract:

System and methods are provided for monitoring circuit performance and correcting for variations in current reference signals to maintain a desired Voltage Output Differential (VOD) between the two differential output signals. A voltage signal associated with VOD is compared to a signal that is set to a desired voltage level based on a desired VOD. By determining whether the VOD level is higher or lower than the desired level, adjustments are made to at least one of an output current source level and an output current sink level. An increase in the source and sink currents at the output results in an increased VOD, while a balance decrease in the source and sink currents results in a decreased VOD.

US Patent:

6766395, Jul 20, 2004

Filed:

Apr 17, 2001

Appl. No.:

09/836041

Inventors:

Steven J. Tinsley - Garland TX
Julie Hwang - Richardson TX
Mark W. Morgan - Allen TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G06F 1300

US Classification:

710100, 714 43, 710305, 327520

Abstract:

A driver ( ) which meets wide common mode voltage requirements is provided. Output passgates ( ) protect sensitive line driver circuitry ( ) from extreme bus voltages; enabling/disabling circuits ( ) detect fault conditions to ensure the line driver is disabled when needed, and pull-ups ( ) assist in line driver start up by preventing negative voltage conditions on the bus driven by the line driver.

US Patent:

6847232, Jan 25, 2005

Filed:

Jan 29, 2002

Appl. No.:

10/059987

Inventors:

Steven Tinsley - Garland TX, US
James Dietz - Prosper TX, US
Mark Morgan - Allen TX, US

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03K 190175

US Classification:

326 84, 326 86, 326 89, 326 91

Abstract:

A system and method is described for a driver circuit used for high speed data transmission in LVDS and CML transceiver device applications. The transceivers are intended to receive a low voltage differential input signal and interchangeably drive a standard LVDS load with a TIA/EIA-644 compliant LVDS signal, and a standard CML load with a standard CML compatible signal. The driver circuit operates at speeds up to 1. 36 Gbps, making it compatible with the OC-24 signaling rate for optical transmission. To accomplish this, the driver uses a mixed combination of voltage and current mode drive sections in the output circuit when coupled to LVDS loads, and when the driver is coupled to CML loads, operates purely in a current mode using only the current mode drive section. MOS transistors and a current source are used in the current mode switch portion to switch the drive with a constant current at the high speeds, and NPN transistors in the voltage mode output portion provide variable impedance for the output circuit. A common mode compensation circuit using a feedback voltage from the load generates a compensation signal for variable impedance control of the NPN transistors to yield a regulated voltage for the common mode dc voltage.