Texas Instruments Corporation

Texas Instruments France

Paolo Giovanni Cusinato

Philippe Perney

Christian V Sorace

Frederic Kubelec

Pierre Michel Carbou

Lorenzo Indiani

Francois Bauduin

Gwenaelle Merrien

Frederic Ballin

Christain Sorace

Frederic Residence Le Flavia Kubelec

Frederic Res Le Flavia Batiment Kubelec

An amplifier () for voice or audio signals, and particularly for headset applications, uses a low gamplifier () for initially charging an output node (OUT) at the beginning of a power-on phase. After charging the output node, a main amplifier () is enabled to amplify the voice or audio signal. At power-down, a sample-and-hold circuit () drives an output transistor to discharge an AC coupling capacitor (). Thus, spikes at the output node are eliminated and an external filtering capacitor is not needed.

Amplifier with sample and hold output and low drive stage

Multi-stage amplifiers to reduce pop noise

A temperature compensated current source forms an uncompensated source current that is proportional to a reference voltage applied to an impedance, wherein the impedance varies with temperature. A temperature compensation current is formed that is proportional to absolute temperature (IPTAT). The uncompensated source current and the temperature compensation current is combined to form a temperature compensated source current and provided as an output of the current source.

Temperature compensated current source

At least some embodiments include a LED driver system. The system includes multiple branches of series-coupled LEDs, multiple current sources, and control logic. Each of the current sources is coupled to a separate branch of series-coupled LEDs. The control logic is coupled to the current sources, and is configured to regulate current through each branch based at least in part on a feedback voltage measured at a node in one of the branches.

Systems and methods for driving light-emitting diodes

The present disclosure describes systems and methods for driving light emitting diodes (LEDs). At least some embodiments include an LED driver system that includes a power supply, a plurality of current sources (each current source coupled between a common return resistor and one of a plurality of branches of series coupled LEDs, and each branch coupled between a corresponding current source and the power supply), and control logic coupled to the current sources (the control logic capable of controlling the current flow through each current source). Each of the current sources allows current to flow during one of a plurality of substantially non-overlapping time periods within a repeating time interval, each current source allowing current to flow during a different time period. The magnitude of the current flowing through each current source is substantially the same and is regulated based upon a feedback voltage across the common return resistor.

Unbalanced plural string LED driver with common return resistor

Growing community of inventors

Villeneuve-Loubet, France

Paolo Giovanni Cusinato