Linear Technology Corporation

Analog Devices,inc.

Analog Devices International Unlimited Company

Linear Technology Holding LLC

Jindong Zhang

Jian Li

Owen Jong

Ya Liu

Yingyi Yan

Min Hao Chen

Dongwon Kwon

Min Kyu Song

Mark Frederick Hartman

Manjing Xie

Xuebing Chen

Several current sensing techniques are described that may be used to obtain an accurate current signal, which may help to achieve the best performance with a trans-inductor voltage regulator (TLVR) topology. The techniques may have the coupling effect from the secondary side included, so the current sensing signal is accurate for the regulation and other functions related to the current signal. The current sensing techniques may have more accurate gain and phase information in the middle frequency and high frequency ranges. The coupling effect from the secondary side may be well represented in the current sensing signal. The advantages of TLVR topology may be enhanced with accurate current information.

Trans-inductor voltage regulator current sensing techniques

Techniques for fine tuning efficiency of a power converter are provided. In an example, a method can include acquiring a plurality of samples of an electrical characteristic of the power converter over a range of switching frequencies of the power converter to provide a plurality of sample pairs, estimating a corner value of the electrical characteristic based on the plurality of samples pairs, estimating a corresponding frequency associated with the corner value of the electrical characteristic based on frequencies of the plurality of sample pairs, and setting a switching frequency of the power converter at the corresponding frequency.

Switching power converter frequency optimization techniques

A current sensing technique for coupled inductors in switching regulator circuits, where the current sensing technique can provide the current information needed for a power converter design and can be implemented as a real-world solution. The current sensing techniques can provide complete information of the coupled inductor current, such as peak current, valley current, and intermediate ripples. The current sensing techniques can use a simple RC network, such as two resistors and two capacitors for 2-phase operation. The techniques, however, are not limited to two-phase operation. The current sensing techniques of this disclosure can be extended to power stage assembly implementations, e.g., DrMOS modules, with current output in order to increase signal-to-noise ratio, which is significant for reliable control. in addition, the current sensing techniques of this disclosure can be extended to multi-phase operation, such as three or more phases.

Current sensing techniques for power converter circuits

A multi-phase buck-boost converter circuit comprises a buck circuit stage, a boost circuit stage, and a control circuit. The buck circuit stage is connected to an input of the buck-boost converter circuit to receive an input voltage. The boost circuit stage includes multiple boost circuits connected in parallel. The boost circuit stage is coupled to the buck circuit stage and an output of the multi-phase buck-boost converter circuit. Each boost circuit includes an inductor coupled to the buck circuit stage. The control circuit operates the multiple boost circuit stages out of phase with respect to each other in a boost mode, operates the buck circuit stage in a buck mode, and operates the multiple boost circuit stages out of phase with respect to each other and operates the buck circuit stage in a buck-boost mode.

Multi-phase buck-boost converter

A current sensing technique for coupled inductors in switching regulator circuits, where the current sensing technique can provide the current information needed for a power converter design and can be implemented as a real-world solution. The current sensing techniques can provide complete information of the coupled inductor current, such as peak current, valley current, and intermediate ripples. The current sensing techniques can use a simple RC network, such as two resistors and two capacitors for 2-phase operation. The techniques, however, are not limited to two-phase operation. The current sensing techniques of this disclosure can be extended to power stage assembly implementations, e.g., DrMOS modules, with current output in order to increase signal-to-noise ratio, which is significant for reliable control. In addition, the current sensing techniques of this disclosure can be extended to multi-phase operation, such as three or more phases.

A multi-phase hybrid DC-DC converter using a switched-capacitor technique is described. The multi-phase hybrid converter can reduce the volt-seconds on the inductors of the converter, which can allow for a reduction in the size of the inductors. In addition, the multi-phase hybrid converter can utilize inductors as current sources to charge and discharge the flying capacitors, which can reduce the size of the mid capacitor and increase solution density. Because charging and discharging are performed by inductors, the multi-phase hybrid converter can eliminate the capacitor-to-capacitor charge transfer. As such, the multi-phase hybrid converter does not need high capacitance to achieve high efficiency operation, which can further increase solution density.

Multi-phase hybrid converter

A voltage converter circuit comprises a charge pump circuit, a pulse width modulation (PWM) filter stage circuit, and a control circuit. The charge pump circuit includes multiple switching transistors arranged as a switching bridge including a first bridge portion connected to a second bridge portion; a midpoint capacitor connected to a circuit node coupling the first bridge portion and the second bridge portion; and a first flying capacitor coupled to the first bridge portion and the second bridge portion. The PWM filter stage circuit is coupled to the charge pump circuit and a first input/output terminal and includes a first inductor coupled to the first flying capacitor and the second bridge portion of the switching bridge. The control circuit is configured to control activation of switching transistors of the switching bridge to generate a regulated voltage at the first input/output terminal.

High conversion-ratio hybrid switched power converter

A hybrid power converter includes a primary switching circuit, an LC circuit, and a secondary switching circuit. The primary switching circuit includes three or more switching transistors in series that may turn on or off according to a switching cycle to generate a series of voltage pulses at a connecting node between two switching transistors. The LC circuit may be coupled via the to the secondary switching circuits to the connecting node of the primary switching circuit. The LC circuit may receive, from the primary switching circuit, a series of pulses via the secondary switching circuits and may generate an inductor current in the LC circuit. The inductor current may charge a capacitor of the LC circuit to generate an output voltage of the hybrid power converter. The output voltage may have a reverse polarity with respect to an input voltage that may be coupled to the primary switching circuit.

Hybrid inverting PWM power converters

A power interface system for reducing power variations includes multiple control circuits configured to control a plurality of switching regulators operating at different frequencies to provide a shared output power to a load. Each control circuit receives a power variation signal resulting from a power variation in the shared output power of the plurality of switching regulators, separates a respective frequency component from multiple frequency components of the power variation signal, and controls, based on the separated respective frequency component, a respective switching regulator of the plurality of switching regulators to source current to, or sink current from, the shared output power until the shared output power reaches a threshold level.

Power interface system for reducing power variations in an output power of switching regulators

A hybrid power converter circuit includes a switched-capacitor power converter stage and a pulse-width modulation (PWM) or resonant output circuit coupled to a switching node of the switched-capacitor power converter stage. In particular, the PWM or resonant output circuit can include a transformer having a primary winding and a secondary winding magnetically coupled to each other, and the secondary winding is coupled to the output node of the power converter. The switched-capacitor power converter stage is coupled between the input node of the power converter and the primary winding of the transformer, and includes capacitors and switches configured to connect the capacitors to the input node during a first phase of operation and connect the capacitors to the primary winding of the transformer of the PWM or resonant output circuit during a second phase of operation.

Hybrid power converters combining switched-capacitor and transformer-based stages

A power interface device includes a main switching converter, an auxiliary switching converter, a feedback sense circuit, an error amplifier, a high pass filter, a transient detection circuit, and an auxiliary control circuit. The transient detection circuit is configured to receive the higher frequency component of the transient signal and output an enable signal when the higher frequency component of the transient signal falls outside of an operating window range defined by a first threshold and a second threshold and output a disable signal when the higher frequency component of the transient signal stays within the operating window range. The auxiliary control circuit configured to activate the auxiliary switching converter in accordance with the enable signal and to deactivate the auxiliary switching converter in accordance with the disable signal.

Control architecture with improved transient response

A switched capacitor power converter includes multiple switching transistors in a default switching path, and an auxiliary soft-charge bypass circuit which includes one or more auxiliary transistors and an impedance element, and provides an auxiliary circuit path through the auxiliary transistor(s) to charge a plurality of capacitors within the converter circuit when the auxiliary soft-charge bypass circuit is activated and at least one of the switching transistors is deactivated. A corresponding control circuit switches the converter circuit from a soft-charging mode in which the auxiliary soft-charge bypass circuit is activated and a switching transistor is deactivated, to an operational mode in which the auxiliary soft-charge bypass circuit is deactivated, the control circuit periodically switching the one or more auxiliary transistors during the soft-charging mode in place of the deactivated switching transistor(s).

Soft-charging of switched capacitors in power converter circuits

To reduce in-rush currents into a switched capacitor DC/DC converter and detect voltage and current faults, a converter controller is housed along with a current limit series transistor and fault detection circuitry. The series transistor is controlled to limit the in-rush current to a predetermined maximum level during start-up. If the duration of the current limit level, or the time for Vout to achieve a target voltage, exceeds a first threshold time, a first fault detector in the package shuts off the series transistor. During steady state operation, if the input current reaches the limit for a second threshold time or if Vout extends outside a certain range for the second threshold time, a second fault detector in the package shuts off the series transistor.

Switched capacitor DC-DC converter with reduced in-rush current and fault protection

In a current mode controlled switching power supply, current through the inductor is sensed to determine when to turn off or on the switching transistors. The inductor current has a higher frequency AC component and a lower frequency DC component. The AC current feedback path, sensing the ramping ripple current, is separate from the DC current path, sensing the lower frequency average current. Separating the current sensing paths allows the signal to noise ratio of the AC sense signal to be increased and allows the switching noise to be filtered from the DC sense signal. The gain of the DC sense signal is adjusted so that the DC sense signal has the proper proportion to the AC sense signal. The AC sense signal and the DC sense signal are combined by a summing circuit. The composite sense signal is applied to a PWM comparator to control the duty cycle of the switch.

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Fremont, CA, United States of America

Jindong Zhang