Capella Microsystems Inc.

Integrated Memory Logic, Inc.

Ing-Jye Lan

Brian N Kuo

Koon Wing Tsang

Pei-Ling Hsu

In one aspect, a system provides gamma correction in a thin-film-transistor (TFT) liquid-crystal-display (LCD). The system includes a digital-to-analog converter operable to receive digital control data. The digital-to-analog converter is operable to provide an output voltage for gamma correction in response to the digital control data.

Digital-to-analog converter (DAC) for gamma correction

A first device comprising a first current mirror is used to amplify the output of a first photodetector. A second device comprising a current mirror arrangement is employed to amplify the output of a second photodetector. The outputs of the two devices are then compared to provide a signal useful for many applications, including that for determining the position of a rotating member or of a member in relative motion to another member. Preferably, no feedback action is used for the amplification of the output of at least one of the photodetectors.

Photodetection system and circuit for amplification

The DC level of the output of an amplifier may be dynamically adjusted depending on the operating conditions of the amplifier by comparing the output of the amplifier to a set reference value using a comparator. The output of the comparator is then fed to a state machine which adjusts the DC level of the amplifier output in an autocalibration process until the DC level of the output of the amplifier is substantially equal to the reference value. An undervoltage lockout circuit detects a power supply to the amplifier and causes the calibration to be initiated only when the power supply meets certain requirements. A change in the gain setting in the amplifier is also detected for automatically initiating the calibration process.

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Saratoga, CA, United States of America

Ing-Jye Lan