A method includes receiving, at a multimedia device, a data stream representing multimedia content, the data stream comprising first timing information for the multimedia content, and metadata representing interactive event information associated with the multimedia content, the metadata comprising second timing information for the interactive event information. During the playback of the multimedia content, a first user interactive event is identified that is associated with a first time point in the playback of the multimedia content based on the interactive event information, and the first user interactive event is performed concurrent with the first time point in the playback of the multimedia content.

A generic route for synthesis of asymmetric nanostructures. This approach utilizes submicron magnetic particles (Fe3O4—SiO2) as recyclable solid substrates for the assembly of asymmetric nanostructures and purification of the final product. Importantly, an additional SiO2 layer is employed as a mediation layer to allow for selective modification of target nanoparticles. The partially patched nanoparticles are used as building blocks for different kinds of complex asymmetric nanostructures that cannot be fabricated by conventional approaches. The potential applications such as ultra-sensitive substrates for surface enhanced Raman scattering (SERS) have been included.

Methods, apparatus, systems, computer programs and computing devices related to biologically assembling and/or synthesizing peptides and/or proteins are disclosed.

Systems and methods are provided that may be implemented to provide a mechanical indicator to correlate magnetic disk drive IOP performance with features of mechanical and/or acoustic vibrational frequencies that are generated and captured or sensed outside of the disk drive itself. In one example, disk drive PES data may be collected concurrently with the capture of mechanical and/or acoustic vibrational data at different and progressive locations of vibration source, vibration path and vibration receiver in a disk drive operating environment, e.g., such as for disk drives installed within a server and/or storage chassis enclosure. In such case, PES threshold may be utilized to correlate performance of Drive IOP or drive servo-mechanical performance as a function of measured characteristics of vibration source/s that impart vibration to a disk drive.

A retainer of synthetic resin is provided in such a way that abnormal heat generation in a bearing and wear of the retainer due to interference between the retainer and balls are less likely to arise while the bearing is rotating at a high speed. A retainer (5) of synthetic resin includes two annular members (10) made of synthetic resin and facing each other in the axial direction, the annular members defining therebetween a plurality of circumferentially spaced apart pockets (11) in which respective balls (4) are received. Concave spherical surfaces (23) are formed at the circumferential ends of the respective pockets (11) so as to extend along the outer peripheries of the balls (4), and cylindrical surfaces (22) are formed at the axial ends of the respective pockets (11).

A synthetic resin-made thrust sliding bearing 1 includes a synthetic resin-made upper casing 2 which is fixed to a vehicle body side via a mounting member; a synthetic resin-made lower casing 3 which is superposed on the upper casing 2 so as to be rotatable about an axis O in a circumferential direction R relative to the upper casing 2; and a synthetic resin-made sliding bearing piece 5 disposed in a space 4 between the upper casing 2 and the lower casing 3.

Techniques are described for utilizing synchronous APIs which normally block callers until a result is returned. In particular, the techniques described herein enable an application or other programming construct to boost performance by executing synchronous APIs (e.g., long running time APIs) within a proxy container rather than executing the synchronous APIs in the context of the application itself. Since the proxy is a separate process or thread, the caller application is thereby released from waiting for the synchronous API call and may proceed with other processing instead of waiting for the synchronous API to return. The application may then monitor the proxy to determine whether a result has been received, such as by periodically polling the proxy.

Through an asynchronous callback enhancement, a thread makes a non-blocking request (e.g., send, receive, I/O) to a message passing interface library, and a callback routine is associated with the request as an asynchronous callback to the thread. The callback is queued for execution in the requesting thread and so has a deterministic execution context. Callback queuing may occur in response to another thread detecting that the request is complete. Further control over callback execution is provided by state transitions which determine whether the thread is open to processing (e.g., executing) an asynchronous callback. Callback association is done by a broad or by narrow association routines. An application which has processes organized in ranks, each including a communication thread with associated callback(s), and multiple worker threads. Interruptible wait enhancements may also be present.

Process for the preparation of vinyl aromatic (co) polymers grafted on an elastomer in a controlled manner, comprising: dissolving an elastomer functionalized with bromoalkanes and nitroxy radicals, soluble in non-polar solvents, in a liquid phase consisting of a mixture of vinyl aromatic monomer(s)/polymerization solvent; feeding at least one radical initiator to the mixture, containing the functionalized elastomer in solution, and polymerizing the mixture thus obtained at a temperature higher than or equal to 1200 C; recovering the vinyl aromatic (co) polymer obtained after devolatization; and recycling the solvent/monomer(s) mixture, coming from the devolatization, to step (a).

Various embodiments provide for systems and methods for signal conversion of one modulated signal to another modulated signal using demodulation and then re-modulation. According to some embodiments, a signal receiving system may comprise an I/Q demodulator that demodulates a first modulated signal to an in-phase (“I”) signal and a quadrature (“Q”) signal, an I/Q signal adjustor that adaptively adjusts the Q signal to increase the signal-to-noise ratio (SNR) of a transitory signal that is based on a second modulated signal, and an I/Q modulator that modulates the I signal and the adjusted Q signal to the second modulated signal. To increase the SNR, the Q signal may be adjusted based on a calculated error determined for the transitory signal during demodulation by a demodulator downstream from the I/Q modulator.

According to typical practice of the present invention, temporal identifiers are simultaneously associated with (i) video and (ii) numerical data while these data are contemporaneously collected by, respectively, (i) a video camera filming an event and (ii) a data acquisition system acquiring numerical data from sensor(s) obtaining sensory information relating to the event. Various modes of inventive practice provide for time codes and/or markers as the temporal identifiers. The video and the numerical data are each converted to a digital form that furthers their mutual compatibility, the video to a compressed/encoded video file, the numerical data to an Adobe XMP data file. The compressed/encoded video file and the XMP data file are merged whereby the temporal identifiers are aligned with each other. The merged video file has numerical data embedded therein and is displayable so that the video and the numerical data are synchronized in comportment with actual real-time occurrence.

Systems and methods are provided for generating a composite video based on a plurality of asynchronously recorded input video streams. A plurality of segments of the input video streams are identified. A number of the input video streams that were recording during the particular segment are determined. A video display configuration for the particular segment is determined based on the number of video streams that were recording, where the video display configuration includes a display sub-region for each of the number of video streams that was recording. A composite video is generated, where the composite video includes a portion of video associated with each of the segments, where the composite video portion associated with the particular segment is formatted according to the video display configuration and displays the video streams that were recording during the particular segment in the display sub-regions of the video display configuration.

A method for play synchronization and a device using the same are provided. A first device stores time-based content play information. The first device plays content according to the time-based content play information. The first device transmits the time-based content play information to a second device so that the second device plays the content according to the time-based content play information. Accordingly, the content played by one device can be played by another device concurrently.

A device and method to determine the stopping rotor position of a washing machine motor includes an inverter, a permanent magnet synchronous motor, and an electronic motor controller. The controller determines the stopped rotor position of the motor by measuring induced currents in the stator field coils of the motor. While the motor is de-energized and slowly rotating, the controller directs the inverter to connect all of the stator field coils of the motor together. The stator field coils may be connected to a common D.C. rail, output from an A.C.-D.C. converter of the washing machine. In an embodiment, the controller determines the rotor position based on the polarities of current induced in the stator field coils. In another embodiment, the controller determines the rotor position based on the phase angle and angular frequency of the three phase currents, transformed into a stationary reference frame.

A synergy-based human-machine interface that uses low-dimensional command signals to control a high dimensional virtual, robotic or paralyzed human hand is provided. Temporal postural synergies are extracted from angular velocities of finger joints of five healthy subjects when they perform hand movements that are similar to activities of daily living. Extracted Synergies are used in real-time brain control, where a virtual, robotic or paralyzed human hand is controlled to manipulate virtual or real world objects.

The present invention is concerned with a novel process for the preparation of 1-(3,5-bis(trifluoromethyl)phenyl)ethan-1-one (CAS 30071-93-3). This compound is useful as an intermediate in the synthesis of therapeutic agents.

A diorganomagnesium-containing synthesis means, a method for its preparation and its use.

The present invention relates to a synthesis method of metal cyclopentadienide by direct reaction of dicyclopentadiene with a group 1 metal in the presence of an aprotic solvent. Unlike the conventional method depending on retro Diels-Alder reaction of dicyclopentadiene to generate indirectly cyclopentadiene, the method of the present invention favors generation of cyclopentadiene and metal cyclopentadienide as well by adding dicyclopentadiene directly when the reaction temperature reaches to the boiling point of a reaction solvent.

The present invention relates to a process of synthesis of α-sialyl oligosaccharides and in particular of 6'-sialyllactose and its salts comprising a step of coupling by Koenigs-Knorr reaction under conditions that allow its use on an industrial scale.

A multi-color harmonic synthesized laser system for laser processing and a laser processing method using multi-color harmonic synthesized laser are disclosed. The multi-color harmonic synthesized laser system includes a laser source for providing a single laser wave, a converter for converting the single laser wave into a plurality of harmonic waves with different frequencies, and a modulating unit for modulating amplitudes and relative phases of the harmonic waves to form a plurality of modulated harmonic waves, so as to synthesize the modulated harmonic waves as a single synthesized laser wave, wherein the single synthesized laser wave is focused on an object to perform a laser processing. The converter includes a plurality of non-linear crystals for converting the single laser wave into a fundamental harmonic wave and a plurality of multi-frequency harmonic waves. The harmonic waves are coherent and collinear, and the phases of the harmonic waves are related to one another.

A method for quasi-synchronous tuning of wavelength or frequency of grating external-cavity semiconductor laser and a corresponding semiconductor laser are provided. A grating or mirror is rotated around a quasi-synchronous tuning point (Pq) as rotation center, so as to achieve the frequency selections by grating and resonance cavity in quasi-synchronous tuning, wherein the angle of the line between the quasi-synchronous tuning point (Pq) and a conventional synchronous tuning point (P0) with respect to the direction of light incident on the grating is determined according to the angle difference between the incidence angle and diffraction angle of light on the grating. According to present invention, approximately synchronous tuning of laser is achieved with a simple and flexible design.

A method for generation of electromagnetic radiation has the following method steps: generation of electromagnetic radiation at a useful frequency,division of the electromagnetic radiation into a useful beam and a secondary beam,frequency shift of the electromagnetic radiation of the secondary beam,control of the useful frequency as determined by a manipulated variable, wherein the manipulated variable is derived from the frequency-shifted radiation of the secondary beam.

The invention relates to a self-tapping and self-boring osteosynthesis screw for compressive orthopaedic surgery, characterised in that, in the bone engagement regions, at both the distal portion (A1a) and at the proximal portion (A2a), the sum of the angles defining the outer taper of the shank (f) and the taper of the crest line of the screw thread pitch (P) is higher than 45°, and in that the leading portion (i.e. the most distal one) of each thread includes a plurality of cutting edges (AR) obtained by stock removal.

A display panel drive circuit includes a shift register constructed of unit circuits connected in stages. The unit circuits generate signal line selection signals, respectively, which signal line selection signals are made active for a respective certain period of time to form a respective pulse, and the pulses are outputted successively from respective unit circuits in order of ordinal number starting from a first stage until an end stage. In at least one embodiment, each of the unit circuits receive (i) clock signals generated based on a sync signal received from outside of the display panel drive circuit, (ii) a start pulse signal generated based on the sync signal, or a signal line selection signal generated in a stage different from its own stage, and (iii) a clear signal. The clear signal is made active in a case where anomalousness is included in the sync signal, and no pulse is outputted from the shift register until a subsequent vertical scanning period starts. This configuration achieves a display panel drive circuit which prevents display disorder or holds down increase in load given to a power source, each of which occurs in a case where anomalousness is included in the sync signal.

Methods, devices and system are provided. One method includes capturing activity data associated with activity of a user via a device. The activity data is captured over time, and the activity data is quantifiable by a plurality of metrics. The method includes storing the activity data in storage of the device and, from time to time, connecting the device with a computing device over a wireless communication link. The method defines using a first transfer rate for transferring activity data captured and stored over a period of time. The first transfer rate is used following startup of an activity tracking application on the computing device The method also defines using a second transfer rate for transferring activity data from the device to the computing device for display of the activity data in substantial-real time on the computing device.

A method and system for synchronizing the output signal phase of a plurality of frequency divider circuits in a local-oscillator (LO) or clock signal path is disclosed. The LO path includes a plurality of frequency divider circuits and a LO buffer for receiving a LO signal coupled to the plurality of frequency divider circuits. The method and system comprise adding offset voltage and setting predetermined state to each of the frequency divider circuits; and enabling the frequency divider circuits. The method and system includes enabling the LO buffer to provide the LO signal to the frequency divider circuits after they have been enabled. When the LO signal drives each of the frequency divider circuits, each of the frequency divider circuits starts an operation. Finally the method and system comprise removing the offset voltage from each of the frequency divider circuits to allow them to effectively drive other circuits.

An open loop clock divider circuit includes (a) a first divider configured to receive an incoming clock signal and output a first divided clock signal, (b) a flying-adder synthesizer configured to fractionally divide the first divided clock signal and output a fractionally divided clock signal, and (c) a second divider configured to receive the fractionally divided clock signal and output a second divided clock signal. The open loop clock divider circuit advantageously provides a fractional divider in which there is no feedback loop between the source frequency (fs) and the destination frequency (fd). Methods of generating a divided clock signal involving the open loop clock divider circuit are also disclosed.

Techniques for resolving a metastable state in a synchronizer are described herein. In one embodiment, a circuit for resolving a metastable state in a synchronizer comprises a signal delay circuit coupled to a node of the synchronizer, wherein the signal delay circuit is configured to delay a data signal at the node to produce a delayed data signal, and a transmission circuit coupled to the signal delay circuit, wherein the transmission circuit is configured to couple the delayed data signal to the node after a delay from a first edge of a clock signal.

There are provided an accumulator-type fractional N-PLL synthesizer for suppressing the fractional spurious caused by periodically switching a frequency division number of a fractional frequency divider, and a control method thereof. In an accumulator-type fractional N-PLL synthesizer (100), a pulse signal proportional to a fractional phase error occurring between a reference signal and an output signal of a fractional divider (112) for feeding back an output of a VCO (115) of an output stage to a preceding stage is generated using an error signal from an accumulator (120). Through the use of the pulse signal, pulse widths of a UP signal and a DN signal output from a phase detector (140) are controlled so as to reduce a fractional phase error occurring between the UP signal and the DN signal. Thus, the fractional spurious caused by periodically switching the frequency division number of the fractional divider (112) is suppressed.

A current output control device is provided that includes: a current cell array section including plural current cell circuits that are each connected in parallel between a first terminal (power source) and a second terminal (ground) that connect between the first terminal and the second terminal in by operation ON so as to increase control current flowing between the first terminal and the second terminal; and a code conversion section (decoder) that generates signals (row codes, column codes) to ON/OFF control current cells so as to change the number of current cells that connect the first terminal and the second terminal according to change in an externally input code and that inputs the generated signals to the current cell array section.

Disclosed are metal-containing precursors having the formula Compound (I) wherein: —M is a metal selected from Ni, Co, Mn, Pd; and —each of R-1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 are independently selected from H; a C1-C4 linear, branched, or cyclic alkyl group; a C1-C4 linear, branched, or cyclic alkylsilyl group (mono, bis, or tris alkyl); a C1-C4 linear, branched, or cyclic alkylamino group; or a C1-C4 linear, branched, or cyclic fluoroalkyl group. Also disclosed are methods of synthesizing and using the disclosed metal-containing precursors to deposit metal-containing films on a substrate via a vapor deposition process.

In one example implementation, the present disclosure provides a direct current (DC) restoration circuit for restoring the DC component of a synchronization signal provided over an alternating current (AC) coupled link from a transmitting circuit to a receiving circuit. During a period of inactivity in the synchronization signal, the synchronization signal may experience a drift towards the common mode, and may affect the ability for the synchronization signal to properly trigger the receiving circuit. The DC restoration circuit is configured to hold the synchronization signal steady during the period of inactivity, and allow the AC component of the synchronization signal pass through to the receiving circuit during the period of activity to alleviate the problem of baseline drift in the synchronization signal.

The present invention relates to an organotemplate-free synthetic process for the production of a zeolitic material comprising YO2 and X2O3, wherein said process comprises the steps of (1) preparing a mixture comprising seed crystals, one or more sources for YO2, one or more sources for X2O3, and one or more solvents;(2) crystallizing the mixture obtained in step (1) to obtain a zeolitic material comprising YO2 and X2O3 as a crystallization product; wherein Y is a tetravalent element, and X is a trivalent element, and wherein at least a portion of the mother liquor obtained in step (2) is recycled to step (1) as a source for YO2, optionally after concentration of the mother liquor.

The present invention concerns a process for producing ammonia synthesis gas from the reforming of hydrocarbons with steam in a primary reformer (1) equipped with a plurality of externally heated catalytic tubes and then in a secondary reformer (2) together with an oxidant gas. In this process, the reaction of said hydrocarbons with said steam in said primary reformer (1) is performed at an operating pressure of at least 45 bar in the catalytic tubes and a flow of essentially pure oxygen or oxygen-enriched air is added to said secondary reformer as oxidant gas for substantially reforming together with said all the hydrocarbons content of said product gas exiting the primary reformer (1). In the case essentially pure oxygen is used as oxidant gas, a flow of nitrogen is added downstream the secondary reformer (2) to reach a N2/H2 molar ratio corresponding to or close to the stoichiometric ratio for ammonia synthesis. This process allows to obtain high synthesis gas production capacities and lower investment and energy costs.

System and method for sustainable economic development which includes hydrogen extracted from substances, for example, sea water, industrial waste water, agricultural waste water, sewage, and landfill waste water. The hydrogen extraction is accomplished by thermal dissociation, electrical dissociation, optical dissociation, and magnetic dissociation. The hydrogen extraction further includes operation in conjunction with energy addition from renewable resources, for example, solar, wind, moving water, geothermal, or biomass resources.

A semi-continuous process and system thereof, for the synthesis of a narrow particle size distribution Zeigler Natta procatalyst for use in the manufacture of polyolefins. The process comprises: (a) mixing a reaction mixture containing a titanium compound; (b) charging a first reactor with said reaction mixture; (c) removing excess reactants from said first reactor as a filtrate; (d) feeding said filtrate to at least one further reactor; and continuously removing excess reactants from said at least further reactor.

A method for asynchronous operation of a rotary anode of an x-ray emitter, where a torque is exerted onto the rotary anode by an electromagnetic alternating field of a stator with a first frequency is provided. The method includes increasing the first frequency to a second frequency. The second frequency is a whole number multiple of an x-ray trigger frequency. The method also includes simultaneously changing an output of the alternating field such that a rotational frequency of the rotary anode remains unchanged.

A data transmission apparatus disposed within two network layers operative at different data rates is provided. The data transmission apparatus is coupled to a clock generator which provides a reference clock for a lower network layer and is coupled to a frequency synthesizer with an integer division factor that generates a divided clock for an upper network layer according to the reference clock and the integer division factor. The data transmission apparatus includes a first processing circuit and a second processing circuit. The first processing circuit corresponding to the upper network layer receives and transmits data by using the divided clock as its operation frequency. The second processing circuit corresponding to the lower network layer receives and transmits data from the first processing circuit by using the reference clock as an operation frequency for encoding data. The divided clock is generated from the frequency synthesizer with the integer division factor.

Systems and methods for discrete signal synchronization based on a known bit pattern are described. In one aspect of the present subject matter, a discrete signal synchronization system is configured to synchronize a preprocessed discrete signal with a modified discrete signal. The system comprises a processor and a synchronization module coupled to the processor. The synchronization module comprises an extraction module and comparison module. The extraction module determines a bit pattern from the modified discrete signal using Discrete Wavelet Transformation (DWT) and Singular Value Decomposition (SVD). The comparison module compares the determined bit pattern with a known bit pattern of the preprocessed discrete signal and records a time point at which the determined bit pattern matches with the known bit pattern of the preprocessed discrete signal as a synchronization point.

A method is provided for improving synchronization and information transmission in a communication system, including: generating a signal with a centrally symmetric part s(k) exploitable for synchronization; and sending the signal over a communication channel. The signal is based on a uniquely identifiable sequence c(l) from a set of sequences exploitable for information transmission. The centrally symmetric part s(k) is centrally symmetric in the shape of absolute value thereof. The centrally symmetric part s(k) is of arbitrary length N.

A rotary electric machine for a vehicle that is capable of starting synchronous rectification through switching elements after having ensured absence of a short circuit fault. The rotary electric machine includes a multi-phase armature winding, a switching element set that includes a plurality of pairs of upper-arm and lower-arm switching elements to form a bridge rectification circuit together with the armature winding, an on/off-timing setter that sets on/off-timing of each switching element, a switching element driver that drives each switching element at the on/off-timing set by the on/off-timing setter; and a synchronous control start determiner that determines timing when an energization period for the upper-arm switching element and an energization period for the lower-arm switching element occur alternately as start timing of the synchronous rectification.

A generator system includes a generator having a stationary portion and a rotating portion. The generator includes a permanent magnet based exciter with permanent magnets disposed on the stationary portion. A first channel includes a first main field winding and a first main field power converter disposed on a rotating portion. The first main field power converter selectively delivers voltage from the exciter winding to the first main field winding. A second channel includes a second main field winding and a second main field power converter disposed on the rotating portion. The second main field power converter selectively delivers voltage from the exciter winding to the second main field winding. A generator control unit is connected to the first channel and the second channel. The generator control unit monitors an output voltage at each of the first channel and the second channel and generates the first and second control signals based on the output voltage.

An electrical machine includes a stator having a main armature winding, an exciter field winding, and a transformer primary winding. A rotor is operatively connected to rotate relative to the stator, wherein the rotor includes an exciter armature winding operatively connected to the exciter armature winding for field excitation therebetween, a main field winding operatively connected to the main armature winding for field excitation therebetween, and a transformer secondary winding operatively connected to the transformer primary winding to form a rotating transformer. A generator control unit is operatively connected to the main armature winding, exciter field winding, and transformer primary winding to control the main armature and exciter field windings based on excitation in the primary winding received from the transformer secondary winding.

A method for producing process vapor and boiler feed steam in a heatable reforming reactor for producing synthesis gas. The sensible heat of a synthesis gas produced from hydrocarbons and steam can be used so that two types of vapor are produced during the heating and evaporation of boiler feed water and process condensate. The method also includes a conversion of the carbon monoxide contained in the synthesis gas. The method includes an optional heating of the boiler feed water using the flue gas from the heating of the reforming reactor. The sensible heat of the synthesis gas and of the flue gas originating from the heating can be used more efficiently. The disadvantages from the flue gas heating, which are caused by the fluctuating heat supply in the flue gas duct, are avoided. A system for practicing the method is also disclosed.

A method of assembling a syngas cooler is provided. The method includes coupling a supply line within a cooler shell, coupling a heat transfer panel within the cooler shell, and coupling a heat transfer enclosure within the cooler shell such that the heat transfer enclosure substantially isolates the heat transfer panel from the cooler shell. A manifold is coupled in flow communication with the supply line, the heat transfer enclosure, and the heat transfer panel.

A frequency synthesizer for a WLAN transceiver is disclosed that may be used to generate 5.4 GHz and 2.4 GHz signals. The frequency synthesizer may be configured to minimize VCO pulling by using VCO operating frequencies that are not integer multiples of the RF bands. Further, the frequency synthesizer may be configured to minimize interference with other frequency bands used by existing wireless systems.

A time-varying formant is generated at a formant frequency by generating first and second harmonic phase signals having first and second harmonic numbers, respectively, in relation to a modulation frequency. The first and second harmonic phase signals are generated in proportion to a master phase signal, which varies at the modulation frequency, modulo a factor corresponding to their harmonic numbers. First and second sound signals, based on the first and second harmonic phase signals, are frequency modulated to create an arbitrarily rich harmonic spectrum, depending on an FM index. The time-varying formant is generated by generating a time-varying combination of the first and second harmonic sound signals, weighting the first and second harmonic sound signals in accordance with their spectral proximities to the formant frequency. One or more of the harmonic numbers are updated when the time-varying formant frequency passes the frequency of either sound signal.

In a method for performing a synchronized superposed operation of two servomotors, controllers for the servomotors perform the control for achieving the synchronized superposed operation by: calculating, for each of the servomotors, the difference, or differences, between the ideal speed and/or position deviations obtained from a control command and the actual speed and/or position deviations obtained from the rotation of the servomotor; calculating a speed correction quantity, or a speed correction quantity and a current correction quantity, from the discrepancy, or discrepancies, between the differences calculated for both of the servomotors; and adding the correction quantity, or quantities, to a speed command, or to a speed command and a current command, given to the subsidiary shaft side. Thus, a synchronized superposed operation of servomotors in which speeds and responses of the main shaft and the subsidiary shaft are well balanced therebetween can be achieved.

Efficiency of a switch mode power supply (SMPS) is optimized by operating the SMPS in an asynchronous mode when current being supplied therefrom is less than a certain current value and operating the SMPS in a synchronous mode when the current being supplied therefrom is equal to or greater than the certain current value. When the SMPS is operating in the synchronous mode high-side and low-side power transistors alternately turn on and off. When the SMPS is operating in the asynchronous mode only the high-side power transistor turns on and off and the low-side power transistor remains off. When charging a battery with the SMPS discharge of the battery is eliminated when operating in the asynchronous mode at a low current output.

A synchronous DC-DC converter having a soft-stop function includes an output stage for supplying an output voltage, wherein the output stage includes a high-side transistor for charging the output voltage and a low-side transistor for discharging the output voltage; an output control circuit, coupled to the output stage, for controlling the high-side transistor and the low-side transistor of the output stage; at least one protection device, for controlling the high-side transistor to be turned off when a specific situation occurs, in order to stop supplying the output voltage; and a soft-stop control circuit, coupled to the output control circuit, for controlling the low-side transistor of the output stage to be turned on when the protection device controls the high-side transistor to be turned off or the synchronous DC-DC converter is disabled, in order to discharge the output voltage.