Abstract: A multi-phase switching power converter includes a panic mode detector that triggers the activation of each phase in an open-loop mode of operation in which an open-loop duty cycle is used that is greater than a closed-loop duty cycle used during closed-loop operation for the active phases.

Abstract: A circuit and a method for power conversion and for generating an output voltage in accordance with a reference voltage are presented. The power converter has a circuit for filtering the output voltage, an error amplifier circuit that compares the reference voltage and the filtered output voltage for generating an error voltage as a result of the comparison. There is a circuit for driving one or more switching devices in dependence on the error voltage. The error amplifier circuit has a first differential circuit and a first bias current generation circuit for generating a first bias current for the first differential circuit, a second differential circuit and a second bias current generation circuit for generating a second bias current for the second differential circuit, and a circuit for redistributing the first bias current to the second differential circuit or redistributing the second bias current to the first differential circuit.

Abstract: A differential-to-single ended converter circuit can include a latching circuit having first and second latch field effect transistors (FETs) with drains and gates cross-coupled between a first latch node and a second latch node. The source-drain paths of the first and second latch FETs are coupled to a first reference potential node via separate current paths. A sense circuit can include a first sense FET having a source-drain path coupled between the first sense node and the first reference potential node, and a gate coupled to a first input node. A second sense FET has a source-drain path coupled between the second sense node and the first reference potential node, and a gate coupled to a second input node.

Abstract: Disclosed is an oscillator circuit, comprising a crystal oscillator, an amplifier having an input and an output coupled across the crystal oscillator, a comparator having a reference input and an input coupled to the crystal oscillator and a pole network coupled between the comparator and the amplifier.

Abstract: Circuits and methods for aligning two or more signals including a first and second signal. In one embodiment, a shift register generates two or more shifted copies of the second signal, and each of a plurality of phase detectors receives the first signal and one of the shifted copies of the second signal, each phase detector providing an output indicating whether the first signal is substantially aligned with the shifted copy of the second signal. A multiplexer may also be provided for receiving each of the shifted copies of the second signal, the multiplexer having a plurality of select lines coupled with the output signals of the phase detectors. Some embodiments may include a power saving mode.

Abstract: Circuits and methods for aligning two or more signals including a first and second signal. In one embodiment, a shift register generates two or more shifted copies of the second signal, and each of a plurality of phase detectors receives the first signal and one of the shifted copies of the second signal, each phase detector providing an output indicating whether the first signal is substantially aligned with the shifted copy of the second signal. A multiplexer may also be provided for receiving each of the shifted copies of the second signal, the multiplexer having a plurality of select lines coupled with the output signals of the phase detectors. Some embodiments may include a power saving mode.

Abstract: A phase locked loop (PLL) can include a test loop filter (100) that generates a control voltage (VCTRL) for input to a voltage controlled oscillator (VCO). In a test mode, a control voltage can be varied and resulting output frequencies recorded, from which an open loop bandwidth can be determined. A control voltage can be varied by enabling a switch element (104-1) that can provide a current path through load resistance (RL) of test loop filter (100). Current provided to the test loop filter can be varied according to test signals to provide a variable control voltage (VCTRL).

Abstract: An amplifier circuit operable to provide symmetric current limiting. The amplifier circuit includes a common source amplifier for sourcing a current and receiving an voltage input, a current source, and a current limiting device coupled between the common source amplifier and the current source. The current limiting device is operable to limit the current sourced by the common source amplifier. A bias network coupled to the current limiting device biases the current limiting device. An output is coupled to the current limiting device. The amount of current that is sourced to the output of the amplifier circuit may be limited, such that current limiting is symmetrical.

Abstract: An oscillator circuit is provided that is preferably a crystal oscillator, where voltage placed across the crystal is regulated. The regulated voltage or amplitude of the cyclical signal across the crystal is monitored and maintained through a regulation circuit that measures a peak voltage across the crystal. Once the peak voltage exceeds a predetermined setpoint value, then a controller within the regulation circuit will reduce a biasing current through an amplifying transistor within the amplifier coupled across the crystal input and output nodes. By regulating the biasing current, gain from the amplifier is also regulated so that unwanted non-linearities and harmonic distortion is not induced within the crystal to cause frequency distortion and unwanted modes of oscillation within the crystal. The amplifier is preferably symmetrical in that the amplifier sources and sinks equal current to reduce unwanted peaks at the negative or positive half cycles of the sinusoidal signal.

Abstract: A voltage-to-current converter circuit is disclosed. In one embodiment, the present invention includes a first metal oxide semiconductor field effect transistor (MOSFET) stage operable in a low to medium power range. The present invention also includes a second MOSFET stage operable in a medium to high power range. An additive circuit is utilized to add the contributions of both the first MOSFET stage and the second MOSFET stage. A subtractive circuit is further used to subtract either the first MOSFET stage or the second MOSFET stage when both the first MOSFET stage and the second MOSFET stage are operating in the medium power range and outputting current in a voltage-to-current converting circuit.