Abstract: A power converter operates in continuous conduction mode and outputs a regulated output voltage. A feedback-derived signal is used to regulate the output voltage. The feedback-derived signal is sampled at multiple time points during an OFF cycle of a power switch. A current-sense signal is also sampled at one or more time points during an ON cycle of the power switch. The current-sense signal is indicative of an output inductor current of the power converter. A calibrated feedback-derived voltage is then generated based on the multiple voltage samples of the feedback-derived signal and the one or more voltage samples of the current-sense signal. The calibrated feedback-derived voltage is less sensitive to an output inductor current loop resistance than the original voltage samples of the feedback-derived signal. The calibrated feedback-derived voltage also compensates for the nonlinearity of a diode of the output inductor current loop.

Abstract: A DC-to-DC converter comprises an error amplifier, a comparator, a PWM controller, a power switch unit, and a control signal monitoring circuit. The PWM controller receives a comparison signal from the comparator and generates a digital control signal that controls the power switch unit such that the DC-to-DC converter supplies a regulated voltage onto a load. The control signal monitoring circuit monitors the digital control signal and detects either a heavy load or a light load condition based on characteristics of the digital control signal. Under the light load condition, the monitoring circuit generates a first enabling signal such that the DC-to-DC controller operates in a power-save mode. Under the heavy load condition, the monitoring circuit generates a second enabling signal such that the DC-to-DC controller operates in a normal operation mode. The DC-to-DC converter consumes substantially less power in the power-save mode than in the normal operation mode.

Abstract: A power converter having a switched capacitor buck/boost operation has first and second switches coupled to a first switching node, third and fourth switches coupled to a second switching node, a capacitor coupled between the first and second switching nodes, and an inductor coupled to the first switching node. A switch controller controls the switches to operate in voltage step-down mode and voltage step-up mode depending on a difference between converter output voltage VOUT and converter input voltage VIN. In a buck-optimized topology operating in a step-down mode, an output current flowing through the first switching node flows through only one switch at a given time. In a boost-optimized topology operating in a step-up mode, an output current flowing through the first switching node flows through only one switch at a given time. As a result, a more compact and efficient power converter may be realized at lower cost.

Abstract: Techniques for near zero light-load supply current in switching regulators are described. In one aspect a voltage regulator operating a normal mode is generating an error signal indicating a difference between the output and the regulated voltage. A control signal, at least in part based on the error signal, actively controls the output of the regulator. The control signal is monitored over period of time. The monitoring activates a signal indicating when the control signal is inactive for the period of time indicating a light-load condition. The voltage regulator is then placed in a standby mode when the signal is active and the error signal indicates the output is substantially at the regulated voltage. Portions of the voltage regulator are then disabled permitting the voltage regulator to operate at the minimum current draw.

Abstract: An integrated circuit includes a buck converter controller, a PFET, an NFET that is coupled in common drain configuration to the PFET, a first microbump that is connected to the source of the PFET, a second microbump that is connected to the source of the NFET, a third microbump that is connected to the common drain node, a fourth microbump that is connected to a feedback input lead of the controller, and a plurality of other microbumps. The other microbumps are utilized to supply signals to and/or to conduct signals from the controller. A respective one of the four microbumps is disposed to occupy a respective one of the four corners of a square pattern. The other microbumps are disposed in a regular grid along with the four microbumps, but none of the other microbumps is disposed between any two of the four microbumps.

Abstract: A flyback AC/DC switching converter has a constant voltage (CV) mode. The CV mode has sub-modes. In one sub-mode (“mid output power sub-mode”), the output voltage (VOUT) of the converter is regulated using both pulse width modulation and pulse frequency modulation. Both types of modulation are used simultaneously. In a second sub-mode (“low output power sub-mode”), VOUT is regulated using pulse width modulation, but the converter switching frequency is fixed at a first frequency. By setting the first frequency at a frequency above the frequency limit of human hearing, an undesirable audible transformer humming that might otherwise occur is avoided. In some embodiments, the converter has a third sub-mode (“high output power sub-mode”), in which pulse width modulation is used but the switching frequency is fixed at a second frequency. By proper setting of the second frequency, undesirable EMI radiation and other problems that might otherwise occur are avoided.

Abstract: A single terminal is usable to configure an integrated circuit into one of three states. A circuit within the integrated circuit is coupled to the terminal and determines whether the terminal: 1) is tied low by an external connection, or 2) is tied high by an external connection, or 3) is floating or is substantially floating. If the circuit determines that the terminal is floating or is substantially floating, then the circuit sets an operational characteristic of a portion of the circuit (for example, sets a maximum current with which the circuit charges a battery) to have a value that is a function of a resistance of an external resistor coupled to the terminal. If no external resistor is present, then the terminal is floating and the operational characteristic is set to have a zero value. The terminal and circuit are particularly suited to use in a USB battery charger.

Abstract: A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current.

Abstract: A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls a switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the frequency and pulse width controls the peak of the inductor current.

Abstract: A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls a switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the frequency and pulse width controls the peak of the inductor current.

Abstract: Techniques for near zero light-load supply current in switching regulators are described. In one aspect a voltage regulator operating a normal mode is generating an error signal indicating a difference between the output and the regulated voltage. A control signal, at least in part based on the error signal, actively controls the output of the regulator. The control signal is monitored over a period of time. The monitoring activates a signal indicating when the control signal is inactive for the period of time indicating a light-load condition. The voltage regulator is then placed in a standby mode when the signal is active and the error signal indicates the output is substantially at the regulated voltage. Portions of the voltage regulator are then disabled permitting the voltage regulator to operate at the minimum current draw.

Abstract: A lower-cost and more precise control methodology of regulating the output voltage of a flyback converter from the primary side is provided, which works accurately in either continuous voltage mode (CCM) and discontinuous mode (DCM), and can be applied to most small, medium and high power applications such cell phone chargers, power management in desktop computers and networking equipment, and, generally, to a wide spectrum of power management applications. Two highly integrated semiconductor chips based on this control methodology are also described that require very few components to build a constant voltage flyback converter.

Abstract: A start-up time accelerator is described for a switch controller that controls turning on or off a switch in a switching regulator. The start-up time accelerator uses the switch as a current amplifier and provides the amplified current to a capacitor using a current amplification path. In one example, the capacitor provides the bias voltage to a switch controller for the switch. Providing an amplified current to the capacitor accelerates the rate at which the bias voltage increases and reduces the time until the bias voltage reaches the turn-on threshold voltage of the switch controller. After the turn-on threshold voltage of the switch controller is reached, a second path is enabled for current to and from the capacitor and the capacitor provides the bias voltage to the switch controller until a voltage from an output voltage terminal is sufficiently high to provide the bias voltage for the switch controller through an auxiliary winding of a transformer.

Abstract: A primary side controlled power converter having a voltage sensing means coupled to a transformer of the power converter and configured to provide a voltage feedback waveform representative of an output of the transformer is provided. A primary switching circuit operates to control energy storage of a primary side of the transformer. The primary switching circuit is operable during an on time and inoperable during an off time. The on and off time is switched at a system frequency. A feedback amplifier generates an error signal indicative of a difference between the voltage feedback waveform and a reference voltage. A sample and hold circuit samples the error signal at a periodic frequency during the off time. An error signal amplifier is configured to provide the sampled value to the primary switching circuit wherein the primary switching circuit controls the transformer and thereby regulates an output of the power converter.

Abstract: An integrated circuit (IC) and fabrication method thereof is provided that include the steps of specifying a plurality of required tile modules suitable for a particular end-application, each of the modular tiles being configured to perform a predetermined function and constructed to have approximately the same length and width dimensions. The modular tiles are used to form the IC in a standard IC fabrication process. In many implementations, the physical layout of the IC does not include the step of routing. Capabilities also include configuring the modular tiles to have programmable performance parameters and configuring the modular tiles to cooperate usefully with one another based on a programmable parameter.