Abstract: Provided is a foldable stringed having a rotating neck in which the fret board in the folded position is opposite the rear face and the mechanism employs a flexible cable system under variable tension.

Abstract: Provided is a foldable stringed having a rotating neck in which the fret board in the folded position is opposite the rear face and the mechanism employs a flexible cable system under variable tension.

Abstract: A stacked die power converter package includes a lead frame including a die pad and a plurality of package pins, a first die including a first power transistor switch (first power transistor) attached to the die pad, and a first metal clip attached to one side of the first die. The first metal clip is coupled to at least one package pin. A second die including a second power transistor switch (second power transistor) is attached to another side on the first metal clip. A controller is provided by a controller die attached to a second metal clip on one side of the second die, a controller die attached to the second die, or the controller is integrated on the second die. The controller is coupled to both a first control node of the first power transistor and a second control node of the second power transistor.

Abstract: A converter for a multi-phase current network can include a plurality of current sensors, each of the plurality of current sensors being configured to detect current for a respective phase of the multi-phase network. A current averaging circuit is configured to provide an indication of the average current for the multi-phase network based on the current detected by each of the plurality of current sensors. A modulator is configured to modulate at least one phase of the multi-phase network independently of each other phase of the multi-phase network based on a difference between the current detected for the at least one phase and the average current for the multi-phase network.

Abstract: A converter for a multi-phase current network can include a plurality of current sensors, each of the plurality of current sensors being configured to detect current for a respective phase of the multi-phase network. A current averaging circuit is configured to provide an indication of the average current for the multi-phase network based on the current detected by each of the plurality of current sensors. A modulator is configured to modulate at least one phase of the multi-phase network independently of each other phase of the multi-phase network based on a difference between the current detected for the at least one phase and the average current for the multi-phase network.

Abstract: A switch mode power converter that limits the in-rush current at start-up and reduces the occurrence of output voltage overshoot over a range of switching frequencies. The converter includes at least one Soft-Start (SS)/Frequency-Select(FS) input, at least one oscillator enable input, and an oscillator having at least one control input. Soft-start programming is linked to the frequency selection of the converter. An external capacitor connected between the SS/FS input and ground is employed to program the soft-start time, and the switching frequency generated by the oscillator is selected via the state of the SS/FS input.

Abstract: An improved method of monitoring the output power provided by a switch mode power converter that reduces the overall cost of the converter. The method includes initiating a soft-start procedure for a first output voltage in the event the first voltage channel is enabled. When the first voltage level comes within regulation, a delay counter counts a predetermined number of clock cycles. In the event a second output voltage channel is enabled between the time the first channel is enabled and the time the first voltage comes within regulation, a soft-start procedure is initiated for the second voltage and the delay counter re-starts when the second voltage comes within regulation. After the delay counter finishes counting, the first and second voltages are considered stable and a single Power-Good signal is asserted.

Abstract: A pulse width modulation (PWM) controller includes a shutter circuit interposed between a PWM modulator and a driver circuit. The shutter circuit receives a raw PWM output signal from the PWM modulator and processes the raw PWM signal to eliminate double pulsing that may be present on the raw PWM signal. Bypass logic responsive to a switch or software controlled enable input is provided to permit the shutter circuit to be included in the PWM controller or alternatively, to be bypassed.

Abstract: A switching regulator target voltage is adjusted to a first value corresponding to a pre-charge voltage that is present at a regulator output terminal. The switching regulator responds to a comparison signal resulting from a comparison of the target voltage and a feedback voltage. When the switching regulator is on, the target voltage is adjusted to a second value corresponding to a nominal regulator output voltage. In one embodiment, a synchronous switch is disabled when a lockout circuit receives a disable signal. The lockout circuit is unlocked when an enable signal is provided by a switching controller.

Abstract: A switching regulator target voltage is adjusted to a first value corresponding to a pre-charge voltage that is present at a regulator output terminal. The switching regulator responds to a comparison signal resulting from a comparison of the target voltage and a feedback voltage. When the switching regulator is on, the target voltage is adjusted to a second value corresponding to a nominal regulator output voltage. In one embodiment, a synchronous switch is disabled when a lockout circuit receives a disable signal. The lockout circuit is unlocked when an enable signal is provided by a switching controller.

Abstract: The invention relates to a method of to indicate an over-current condition in a switching circuit. The method includes monitoring a monitor voltage from the switching circuit, charging an energy storage device in response to the monitor voltage and a reference voltage, and generating an indication signal in response to the charging of the storage device. The method can be used to detect over-current conditions during high-speed switching and when transient load conditions and supply line noise are present.

Abstract: In one aspect the invention relates to a method of selecting a state from a plurality of states using a program pin. The method includes connecting the program pin to one of a first current source and a second current source, in response to a first voltage applied to the program pin, to thereby generate a second voltage at the program pin, and selecting a state from the plurality of states in response to the first and second voltages. In another embodiment, the method includes determining whether the first voltage exceeds a first reference voltage. In another embodiment, the method includes connecting the program pin to the first current source if the first voltage does not exceed the first reference voltage, and connecting the program pin to the second current source if the first voltage exceeds the first reference voltage.

Abstract: This invention synchronizes the control signals generated by the out-of-range detection circuits with a predefined event. In one aspect, the invention relates to a method of controlling a switching regulator to regulate an output voltage. The method includes receiving a first enable signal and a second enable signal, comparing a feedback voltage representative of the output voltage to a first reference voltage and generating a first limit signal in response thereto and generating, in response to the first enable signal, a close switch command if the first limit signal indicates that the feedback voltage is less than the first reference voltage. The method further includes comparing the feedback voltage to a second reference voltage and generating a second limit signal in response thereto and generating, in response to the second enable signal, an open switch command if the second limit signal indicates that the feedback voltage is greater than the second reference voltage.

Abstract: This invention synchronizes the control signals generated by the out-of-range detection circuits with a predefined event. In one aspect, the invention relates to a method of controlling a switching regulator to regulate an output voltage. The method includes receiving a first enable signal and a second enable signal, comparing a feedback voltage representative of the output voltage to a first reference voltage and generating a first limit signal in response thereto and generating, in response to the first enable signal, a close switch command if the first limit signal indicates that the feedback voltage is less than the first reference voltage. The method further includes comparing the feedback voltage to a second reference voltage and generating a second limit signal in response thereto and generating, in response to the second enable signal, an open switch command if the second limit signal indicates that the feedback voltage is greater than the second reference voltage.

Abstract: The invention relates to a method of to indicate an over-current condition in a switching circuit. The method includes monitoring a monitor voltage from the switching circuit, charging an energy storage device in response to the monitor voltage and a reference voltage, and generating an indication signal in response to the charging of the storage device. The method can be used to detect over-current conditions during high-speed switching and when transient load conditions and supply line noise are present.

Abstract: In one aspect the invention relates to a method of selecting a state from a plurality of states using a program pin. The method includes connecting the program pin to one of a first current source and a second current source, in response to a first voltage applied to the program pin, to thereby generate a second voltage at the program pin, and selecting a state from the plurality of states in response to the first and second voltages. In another embodiment, the method includes determining whether the first voltage exceeds a first reference voltage. In another embodiment, the method includes connecting the program pin to the first current source if the first voltage does not exceed the first reference voltage, and connecting the program pin to the second current source if the first voltage exceeds the first reference voltage.

Abstract: A circuit for providing a temperature-compensated reference current, the circuit comprising a current mirror and a V.sub.BE multiplier circuit. The current mirror includes a reference transistor with its collector providing the temperature-compensated reference current. The V.sub.BE multiplier circuit connects together the base and collector of the reference transistor so as to provide a voltage differential in a range of values having a greatest lower bound equal to V.sub.BE, and sinks (or supplies) base current to the reference transistor so that the reference current is not appreciably affected by the base current of the reference transistor.

Abstract: A programmable delay circuit employs a comparator to control an output driver. The comparator compares a ramp signal to an error control signal derived from an error amplifier or in the alternative to a disable signal. The output of the comparator is latched on until a reset signal is received. The reset signal is produced when the ramp signal is discharged below a predetermined level. The programmable delay circuit is useful in a secondary side post regulator to control a totem pole driver. The totem pole driver in turn controls a switching device coupled to a voltage on a secondary winding.

Abstract: A programmable delay circuit employs a comparator to control an output driver. The comparator compares a ramp signal with a disable signal or an error control signal derived from an error amplifier. The comparator latches the output on until a reset signal is received. The reset signal is produced when the ramp signal is discharged below a predetermined level. The programmable delay circuit is useful in a secondary side post regulator to control a grounded totem pole driver. The totem pole driver in turn controls a switching device coupled to a voltage on a secondary winding.

Abstract: A sleep switch connected to a ramp pin, an undervoltage lockout circuit and a hysteretic differential comparator for use in the undervoltage lockout circuit are disclosed. An integrated circuit has a comparator that receives a voltage from the ramp pin which it compares with a control voltage. The sleep switch connected to the ramp pin is activated when the ramp pin is below a predetermined voltage threshold at which point it puts the integrated circuit into a low power consumption sleep mode. The undervoltage lockout circuit includes a detection leg connected between the supply terminal and ground. A current supply is enabled when the voltage across a resistive portion of a detection leg rises above a first threshold. A differential comparator is responsive to the detection voltage for enabling the current supply. The differential comparator may include three transistors arranged to provide first and second detection thresholds so as to establish a hysteresis.