Analog Devices,inc.

Linear Technology Corporation

Analog Devices International Unlimited Company

Linear Technology Holding LLC

Yingyi Yan

Owen Jong

Ya Liu

Jindong Zhang

Yi Ding Gu

Jian Li

San Hwa Chee

Xu Zhang

Zhouyuan Shi

Yiding Gu

San-Hwa Chee

Qian Li

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 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 dual-phase hybrid DC-DC converter using a switched-capacitor technique is described. The dual-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 dual-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 dual-phase hybrid converter can eliminate the capacitor-to-capacitor charge transfer. As such, the dual-phase hybrid converter does not need high capacitance to achieve high efficiency operation, which can further increase solution density.

Dual-phase hybrid converter

Pulse width modulation (PWM) controllers for hybrid converters are provided herein. In certain embodiments, a PWM controller for a hybrid converter includes a threshold generation circuit for generating a threshold signal based on an output voltage of the hybrid converter, a threshold adjustment circuit for generating an adjusted threshold signal based on sensing a voltage of a flying capacitor of the hybrid converter, and a comparator that generates a comparison signal based on comparing the adjusted threshold signal to an indication of an inductor current of the hybrid converter. The output of the comparator is used for generating PWM control signals used for turning on and off the switches (for instance, power transistors) of the hybrid converter.

Pulse width modulation controllers for hybrid converters

A switching converter circuit comprises an inductive circuit element; a driver switching circuit configured to provide energy to the inductive circuit element to generate an output voltage of the switching converter circuit, the output voltage having an alternating current (AC) signal component and a direct current (DC) signal component; a current sensing circuit configured to generate a current sense signal representative of inductor current of the inductive circuit element, wherein an output of the current sensing circuit is coupled to a bias circuit node; and a dynamic bias circuit configured to apply a dynamic bias voltage to the bias circuit node, wherein the dynamic bias voltage includes an AC component that tracks the AC signal component of the output voltage.

Dynamic bias technique for enhanced MOSFET on-resistance based current sensing

This disclosure describes techniques to control switching operations of a switching regulator. The disclosure includes a system comprising a switching regulator configured to use an inductor to generate an output voltage signal from a. pulse-width-modulated (PWM) signal by controlling one or more switches of the switching regulator that vary charging operations of the inductor; transient handling circuitry coupled to receive a feedback voltage based on the output voltage signal and configured to generate first and second current signals that represent a difference between the feedback voltage and a reference voltage; and control circuitry configured to generate the PWM signal based on the first and second current signals such that the first current signal changes a frequency of an oscillator used to generate the PWM signal and the second current signal changes a bandwidth of a feedback loop associated with the switching regulator.

Load transient control for switched mode converter

A voltage converter circuit comprises a charge pump circuit, a switching converter circuit, and a control circuit. The charge pump circuit includes multiple switch circuits connected in series. The switching converter circuit includes a first inductor coupled to an output node of the voltage converter circuit, and a second inductor coupled to a series connection of the multiple switch circuits. The control circuit is configured to control activation of the multiple switch circuits to generate a regulated voltage at the output node, and to activate each of the multiple switch circuits when a drain to source voltage of the switch circuit is zero volts.

Zero-voltage switching hybrid switched-capacitor converter

A multiphase switching converter includes a first switching converter circuit including a power stage coupled to a DC voltage supply and a controller. The controller includes an over-current (OC) circuit that can detect an OC event and, upon detecting the OC event, set a command signal to a preset low value and provide a first hiccup signal. A synchronization circuit can generate a second hiccup signal based on the command signal of the OC circuit satisfying a first reference threshold value, and a sampled portion of an output voltage of the power stage satisfying a second reference threshold value. A hiccup timer can be triggered by one of the first hiccup signal or the second hiccup signal to start a hiccup pulse in response to being triggered.

Synchronizing hiccup over-current protection of multiphase switching converters

The subject disclosure includes reducing switching losses at lower load current while maintaining the switching frequency for a hybrid switched capacitor converter circuit. Control circuitry is coupled to the hybrid switched capacitor converter circuit and configured to measure a load current at an output of the hybrid switched capacitor converter circuit in a buck phase mode. The control circuitry is configured to compare the measured load current to set of predetermined thresholds. The control circuitry is configured to drive a first voltage to the second set of transistors that turns on the second set of transistors periodically to regulate the output during the buck phase mode. The control circuitry is also configured to drive a second voltage to the first set of transistors that turns off the first set of transistors for one or more switching cycles while the second set of transistors are turned on based on the comparison.

Light-load efficiency improvement of hybrid switched capacitor converter

In a multiphase, current mode controlled switching power supply, current through the inductors in the various phases is sensed to determine when to turn off the switching transistors. An AC current feedback path, sensing the ramping ripple current, is separate from the DC current path, sensing the lower frequency average current. A shared differential amplifier has its inputs multiplexed to receive only the DC component signals from all the phases. The gain of the amplifier is set so that the DC sense signal has the proper proportion to the AC sense signal. The output of the amplifier is sampled and held for each phase using a second multiplexer. The AC sense signal and the amplified DC sense signal, for each phase, are combined by a summing circuit. The composite sense signal is applied to a comparator for each phase to control the duty cycle of the associated switch.

Multiphase switching power supply with robust current sensing and shared amplifier

In a current mode switching power supply, current through the inductor needs to be sensed to control the peak current. The inductor current includes a DC component and an AC component containing switching noise. To reduce the switching noise, the actual inductor current is sensed to generate a signal, and a first AC component is attenuated by a first RC circuit while not attenuating a first DC component. A second AC component is derived by applying the rectangular wave switch voltage, which is at the duty cycle of the regulator, to a second RC filter, which blocks a second DC component. The second AC component is much larger than the first AC component and does not contain switching noise. The large second AC component, the smaller 'noisy' first AC component, and the first DC component are applied to the first RC circuit to create a low-noise inductor current signal.

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Fremont, CA, United States of America

Yingyi Yan