Hendrik Santo

US Patent:

6433527, Aug 13, 2002

Filed:

Jun 1, 2001

Appl. No.:

09/872871

Inventors:

Mansour Izadinia - Los Altos CA
Hendrik Santo - Milpitas CA

Assignee:

Maxim Integrated Products, Inc. - Sunnyvale CA

International Classification:

G05F 500

US Classification:

323300, 361 85, 363 5601

Abstract:

The present invention offers a low cost, reliable, on chip implementation that takes advantage of the nature of the average current mode topology to detect phase failures within a multi-phase system. The invention further includes sensing average current to the load, generating error voltages and changing duty cycles when the sensed load current is not at the desired level.

US Patent:

7598800, Oct 6, 2009

Filed:

May 22, 2007

Appl. No.:

11/805523

Inventors:

Gurjit S. Thandi - San Jose CA, US
Dilip S - Saratoga CA, US
Hendrik Santo - San Jose CA, US
Kien Vi - Palo Alto CA, US

Assignee:

mSilica Inc - Santa Clara CA

International Classification:

G05F 1/10

US Classification:

327540, 323316

Abstract:

The present invention uses two transistors instead of a sensing resistor to provide a constant current source for a load such as an array of light emitting diodes (“LEDs”). In the present invention, a bias current is applied to a branch of the circuit. The drain-to-source voltages of two transistors are matched. The voltage at the gate of both transistors is controlled based on the bias current and the drain-to-source current of the first of the two transistors. The second of the two transistors is sized such that source current of the second transistor is a multiple of the source current of the first transistor for a given gate voltage. By the techniques of this invention, the load current in a circuit is efficiently kept constant at a multiple of the input bias current.

US Patent:

7663326, Feb 16, 2010

Filed:

May 22, 2007

Appl. No.:

11/805525

Inventors:

Hendrik Santo - San Jose CA, US
Gurjit Thandi - San Jose CA, US
Dilip S - Saratoga CA, US
Kien Vi - Palo Alto CA, US

Assignee:

mSilica Incorporated - Santa Clara CA

International Classification:

H05B 37/02

US Classification:

315309, 315157

Abstract:

The present invention provides a controller for regulating current in LEDs in electronic displays. The controller uses temperature sensing diodes to detect changes in the LED ambient temperature. As the LED ambient temperature changes, the forward voltage of the temperature sensing diode decreases. A signal processor adjusts the current passing through the LEDs based on the temperature induced changes in the forward voltage of the temperature sensing diodes. The present invention can reduce costs over the present methods of regulating current in LEDs and may more easily be integrated into a single integrated circuit chip. The temperature sensing may also be implemented outside the integrated circuit chip.

US Patent:

7777704, Aug 17, 2010

Filed:

Jan 12, 2007

Appl. No.:

11/652736

Inventors:

Dilip S - Saratoga CA, US
Gurjit Thandi - San Jose CA, US
Hendrik Santo - San Jose CA, US
Kien Vi - Palo Alto CA, US

Assignee:

mSilica, Incorporated - Santa Clara CA

International Classification:

G09G 3/32

US Classification:

345 82, 345102, 315291, 315307, 315308, 315311, 315312, 315316, 315320

Abstract:

The present invention relates to displays that use LED strings for backlighting. A lead string is provided with continuous drive voltage and the non-lead strings are provided with pulsed drive pulses. The string having the highest forward voltage is selected as the lead string. Feedback information indicative of the currents flowing through the non-lead strings is used to determine the duty cycles of the voltage pulses provided to drive the non-lead strings. The non-lead strings are controlled using pulsed drive voltages to minimize power dissipation in the circuit.

US Patent:

8049708, Nov 1, 2011

Filed:

Jan 12, 2007

Appl. No.:

11/652739

Inventors:

Hendrik Santo - San Jose CA, US
Dilip Sangam - Saratoga CA, US
Gurjit Thandi - San Jose CA, US
Kien Vi - Palo Alto CA, US

Assignee:

Atmel Corporation - San Jose CA

International Classification:

G09G 3/36

US Classification:

345102, 345 76, 345 82, 345690, 345691, 345692, 345693, 315291

Abstract:

The present invention provides a controller for controlling strings of LEDs in a liquid crystal display. The hybrid controller uses both analog and digital circuit components. Error amplifiers are used to compare analog feedback signals received from the LED strings with reference signals. The results of those comparisons are converted to digital data and processed by a digital signal processor (DSP). The DSP calculates the drive voltages for the LED strings based on the deviation between the actual current flows (represented by feedback signals) and the desired current flows (represented by reference signals) through the LED strings. Analog drivers provide the drive voltages to the LED strings.

US Patent:

8169450, May 1, 2012

Filed:

May 22, 2007

Appl. No.:

11/805522

Inventors:

Hendrik Santo - San Jose CA, US
Gurjit Thandi - San Jose CA, US
Dilip Sangam - Saratoga CA, US
Kien Vi - Palo Alto CA, US

Assignee:

Atmel Corporation - San Jose CA

International Classification:

G09G 5/10

US Classification:

345690

Abstract:

The techniques of the present invention relate to automatically controlling display intensity. The present invention includes a calibration step in which the display intensity settings are correlated to the ambient light intensity conditions. The present invention also includes an automatic adjustment step in which the ambient light intensity is measured and the display intensity is automatically adjusted according to a correlation defined in the calibration step.

US Patent:

8217887, Jul 10, 2012

Filed:

Jan 23, 2008

Appl. No.:

12/018399

Inventors:

Dilip Sangam - Saratoga CA, US
Hendrik Santo - San Jose CA, US
Tushar Dhayagude - Santa Clara CA, US
Klen Vi - Palo Alto CA, US
Sean Chen - Sunnyvale CA, US

Assignee:

Atmel Corporation - San Jose CA

International Classification:

G09G 3/36

US Classification:

345102, 345 82

Abstract:

The present invention discloses apparatus and techniques relating to the intelligent control of a display's backlight LED strings. The present invention provides for controlling the display intensity on a region-by-region basis and for adjusting the intensity multiple times within the duration of a frame. The present invention also provides backlight adjustment in a manner that emphasizes certain colors and deemphasizes certain colors. The present invention also provides for adjustment of the backlight based on the ambient temperature.

US Patent:

8222910, Jul 17, 2012

Filed:

Jul 16, 2009

Appl. No.:

12/504308

Inventors:

Dilip Sangam - Saratoga CA, US
Hendrik Santo - San Jose CA, US
Sean Chen - Sunnyvale CA, US
Minjong Kim - San Jose CA, US
Sivaprakash Kannan - Santa Clara CA, US
Balaji Virajpet - San Jose CA, US

Assignee:

Atmel Corporation - San Jose CA

International Classification:

G01R 31/02

US Classification:

3247503, 32475702

Abstract:

The innovation relates to systems and/or methodologies for error detection during sub-assembly in high voltage analog circuits. A signal driver communicates test signals to one or more high voltage analog circuits, and a state machine compares the electrical and/or thermal responses of the high voltage analog circuits to a set of predetermined expected results (e. g. , signatures). The signal driver and state machine can be incorporated into the high voltage analog circuits. The expected results can be stored in the target circuits in the form of look-up tables, matrices, and so forth. Errors, such as, dry solders and bridge solders can be determined based on the comparison of the obtained responses to the expected signatures.