Texas Instruments Corporation

Texas Instruments Incorporated Deutschland, Gmbh

Martin Rommel

Hans Schmeller

Christophe Vaucourt

Harald Sandner

Helmut Kiml

Erich Bayer

Kevin Scoones

Stefan Reithmaier

Laszlo Goetz

Eckart M&uuml;ller

Helmut Kimi

A method is provided for driving a plurality of light emitters in a plurality of output paths with each output path including at least one light emitter. The method includes the steps of applying a supply voltage level to a plurality of output paths; generating a current for each path during a period of a predetermined length for the output path; sensing a current level for each output path during the period; comparing each sensed current level with a reference level; increasing the supply voltage level if the sensed current level is lower than the reference level; determining a lowest supply voltage level for the worst case output path; and using the lower supply voltage level as a common supply voltage level for all output paths.

LED driver with adaptive algorithm for storage capacitor pre-charge

A method for driving a light-emitting semiconductor is provided. A supply voltage is converted into a secondary output voltage for supplying the light-emitting semiconductor with an output voltage. A level for the supply voltage at the beginning of a high current phase of the light-emitting semiconductor is sensed. A threshold voltage level for the supply voltage level is determined based on the sensed level. The high current phase with the light-emitting semiconductor is stated. The sensed level is continuously compared with the threshold voltage level, and an output current through the light-emitting semiconductor is controlled such that the sensed level does not drop below the threshold voltage level.

Adaptive algorithm for camera flash LED power control vs. battery impedance, state of discharge (SOD), aging, temperature effects

A voltage regulator includes a two-stage feedback circuit for driving a controller formed by a transistorThe feedback circuit includes an error amplifierand an output amplifiera simple compensating circuit in the form of a resistor Rinserted between the inverting inputand the non-inverting inputof the output amplifierresulting in a high phase reserve of the feedback circuit. The resistor Rlimits the gain of the error amplifierfor small load currents by reducing its effective output impedance. This compensating circuit results in the two-stage feedback circuit being highly stable even when very low load currents are involved. This now makes it possible to achieve a very simple linear voltage regulator architecture totally integrated on a single chip. It is especially in battery-powered handhelds such as e.g. mobile phones or electronic organizers that this is important since these devices are often on standby with a low current consumption and activated for use only occasionally.

Voltage regulator

A digital driver circuit with one or more CMOS inverters intended as input stages, whereby for the MOS FETs of the inverters the channel width/length (W/L) ratio increases from stage to stage. The digital driver circuit includes an intermediate stage with two further CMOS inverters, connected between a supply voltage Vcc and ground. The driver circuit also includes an output stage having two MOS FETs with the drain terminals of both the MOS FETs of the output stage connected both to each other and to the output of the circuit, the W/L ratio of both MOS FETs exceeding that of the MOS FETs of the intermediate stage. The switch-over of the two MOS FETs of the output stage, occurring with changes of the digital input signal at the input of the circuit, is offset in time with respect to each other, thereby reducing current peaks.

Digital driver circuit

A loss-of-ground protection circuit for an electronic relay including a control circuit driving a power transistor, and at least one cutoff transistor having a grounded control terminal, the cutoff transistor being interposed between the control circuit and a control terminal of the power transistor, and having a polarity such that loss of ground will cause the cutoff transistor to turn off.

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Freising, Germany

Martin Rommel