This application relates to methods and apparatus for voltage control, and in particular to maintain safe voltages for components of audio driving circuits that are operable in a high voltage mode. An audio driving circuit (100) may include a power supply module (106) and may be operable such that, in use, a voltage magnitude at a source terminal of at least a first transistor (306, 309, 603, 605) of the audio driving circuit can exceed its gate-source voltage tolerance. A voltage generator (111 P) is configured to output a first intermediate voltage (V.sub.SAFEP) to an intermediate voltage path for use as a gate control voltage for at least the first transistor, to maintain its gate-source voltage below tolerance. An intermediate path voltage clamp (114P) is provided for selectively clamping the intermediate voltage path to a voltage level, so as to maintain the magnitude of the gate-source voltage of the first transistor below tolerance. The voltage clamp (114P) is enabled by a reset condition (RST) for the audio driving circuit.

Described is a high speed, low power level shifter circuit which includes a cross-coupled level shifter coupled to a sensing circuit. The sensing circuit turns off a cross-coupled node of a pair of cross-coupled nodes based on detecting that an input voltage has crossed a threshold voltage for a cross-coupled input transistor of a pair of cross-coupled input transistors, i.e. due to switching from a current logic level to an incoming logic level. Once the sensing circuit detects a threshold voltage crossing, a pull-up circuit pulls high a cross-coupled node and cross-coupled source transistor tied to the cross-coupled node. This turns off the cross-coupled source transistor and turns on another cross-coupled source transistor. Two parallel paths are now established to pull the cross-coupled node high, enabling a high-speed transition. The turning off of the cross-coupled source transistor also pulls the output to the incoming logic level.

An integrated driving module includes an oscillator, a PWM unit, a soft start controller, a first driver, and a second driver. The oscillator is connected to a voltage input end and generates an oscillating signal. The PWM unit receives the oscillating signal and generates a first driving control signal and a second driving control signal that are respectively anti-phased. The first driver outputs a first driving output signal to a first output end according to the first driving control signal. The second driver outputs the second driving output signal to a second output end according to the second driving control signal. The integrated driving module only has four connection ends for external connection to provide the two anti-phase driving output signals, such that the circuit design and connection of the primary side of the transformer is greatly simplified. The design limitation and manufacturing cost can be both lowered.

Systems and methods are provided for a level shifter. A level shifter includes a network of transistors configured to receive a signal at a first node in a first voltage domain and to generate a corresponding signal at a second node in a second voltage domain during a transition period of time. A self timing circuit is configured to receive an initiation signal based on the signal at the first node and to generate a voltage transition accelerator signal that is used to pull up the second node prior to the expiration of the transition period of time.

A flip-flop includes a first node charging circuit configured to charge a first node with inverted input data generated by inverting input data, a second node charging circuit configured to charge a second node with the input data, and first through eighth NMOS transistors. The flip-flop is configured to latch the input data at rising edges of a clock signal and output latched input data as output data. The flip-flop includes an internal circuit configured to charge a sixth node with inverted input data generated by inverting the latched input data.

Disclosed are level shifters and methods of performing level shifting. In one embodiment, a level shifter is disclosed comprising an input, cross-coupled/latch circuitry, a first reference node, a second reference node, and output circuitry coupled between the cross-coupled/latch circuitry and an output, wherein the output circuitry sets the output signal to high based on rising edge of a second reference node and sets the output signal to low based on the rising edge of the first reference node. Further, the first reference node and the second reference node are symmetric nodes having signals that are inverse to each other.

Certain aspects of the present disclosure generally relate to a level-shifting circuit. The level-shifting circuit generally includes a first pull-up path having at least one first diode and at least one first transistor, and a second pull-up path having at least one second diode and at least one second transistor. The level-shifting circuit may also include a first pull-down path having a third transistor and a fourth transistor, wherein the fourth transistor is coupled between the third transistor and the first diode; a second pull-down path having a fifth transistor and a sixth transistor, wherein the sixth transistor is coupled between the fifth transistor and the second diode; and an overvoltage protection circuit coupled to gates of the fourth transistor and the sixth transistor.

A circuit with a first transistor includes a first current electrode coupled to a first voltage supply, a second current electrode coupled to a first circuit node, and a gate electrode coupled to receive a first input signal. A second transistor includes a first current electrode coupled to the second current electrode of the first transistor, a second current electrode, and a gate electrode coupled to receive a first bias voltage. A third transistor includes a first current electrode coupled to the second current electrode of the second transistor, a second current electrode coupled to a second circuit node, and a gate electrode. A fourth transistor includes a first current electrode coupled to the second circuit node, a second current electrode coupled to a third circuit node, and a gate electrode coupled to receive a second bias voltage. The gate electrode of the third transistor is coupled to the third circuit node. A fifth transistor includes a first current electrode coupled to the third circuit node, a second current electrode coupled to a second voltage supply terminal, and a gate electrode coupled to receive a second input signal.

A method and system of the branch look-ahead (BLA) instruction disassembling, assembling, and delivering are designed for improving speed of branch prediction and instruction fetch of microprocessor systems by reducing the amount of clock cycles required to deliver branch instructions to a branch predictor located inside the microprocessors. The invention is also designed for reducing run-length of the instructions found between branch instructions by disassembling the instructions in a basic block as a BLA instruction and a single or plurality of non-BLA instructions from the software/assembly program. The invention is also designed for dynamically reassembling the BLA and the non-BLA instructions and delivering them to a single or plurality of microprocessors in a compatible sequence. In particular, the reassembled instructions are concurrently delivered to a single or plurality of microprocessors in a timely and precise manner while providing compatibility of the software/assembly program.

A high-voltage level shifter circuit that is capable of level shifting a signal from a low-voltage rail to a high-voltage rail for effective gate driving of a top power switch, with a short propagation delay and a high common-mode transient immunity (CMTI). The high CMTI high-voltage level shifter circuit can include a differential input and isolation stage, a high dv/dt sensor and cancellation stage, at least one differential and common-mode gain stage, and an output buffer stage.