St-ericsson Sa

St-ericsson India Pvt. Ltd.

St-ericsson Pvt. Ltd.

Sanjeev Ranganathan

Srinath Sridharan

Shyam Somayajula

Lionel Cimaz

Ramkishore Ganti

Arnold J D'Souza

Systems and methods for suppressing pop-up noise in an audio signal are disclosed. The system includes a driver circuit shared by a pin interface and a complementary pin interface. A control unit is coupled to the pin interface and the complementary pin interface. To activate the pin interface, the control unit is configured to first activate the driver output at the complementary pin interface. Once the complementary pin interface achieves a preset voltage, the driver output is switched to the pin interface by the control unit. In addition, the driver circuit can be calibrated for a DC offset on the complementary pin interface by re-using calibration data calculated at the pin interface. Further, DC correction signals can be provided from a pre-biasing circuit based on the calibration data of the driver circuit.

Pop-up noise suppression in audio

A protection circuit protects a receiver from high-energy signals. In one exemplary embodiment, the protection circuit comprises a snapback transistor and a controller. The snapback transistor comprises a gate, a drain connected to an input of the receiver and a source connected to ground. The controller configured to connect the gate to a bias voltage to close the gate in a transmit mode, and to disconnect the gate from the bias voltage to open the gate in a receive mode. The snapback transistor is configured to enter into snapback responsive to a high energy signal at the drain to provide a current path from the drain to the source even when the gate is open and thus protect the receiver.

Isolation and protection circuit for a receiver in a wireless communication device

A multi-standard transceiver comprises a common balun, a controller, at least one first switch, and at least one second switch. The common balun comprises a primary coil and a secondary coil. The at least one first switch connects the primary coil of the balun to a first signal path associated with a first communication standard, or to a second signal path associated with a second communication standard responsive to a control signal provided by the controller. The at least one second switch connects the secondary coil of the balun to a first amplification path associated with the first communication standard, or to a second amplification path associated with the second communication standard responsive to a control signal provided by the controller. A common mixer is configured to provide upconverted signals to one of the signal paths depending on which communication standard has been selected.

Multi-standard transceiver architecture with common balun and mixer

Systems and methods for a low pin architecture to couple speakers with integrated circuits are disclosed herein. In an implementation, the low pin architecture facilitates in reducing the required pin interfaces to couple a low power speaker, a high power speaker, and earphone speakers with integrated circuits (ICs). For this, the high power speaker can be cross-coupled between the pin interfaces that are coupled to the low power speaker and the earphone speakers. These pin interfaces are driven by corresponding driver circuits. In said implementation, some of the driver circuits can be shared to drive multiple pin interfaces. These shared driver circuits include a combined cascode circuit having a first cascode circuit integrated with a second cascode circuit to reliably and selectively drive one or more of the pin interfaces.

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Bengaluru, India

Sanjeev Ranganathan