Abstract:
Disclosed is a hall sensor signal generating device which includes a rotor which has a magnetic property and rotates on the basis of a rotary axis; a hall sensor unit which is disposed to be spaced apart from a stator disposed outside the rotor; and a clock synchronization unit which receives a driving clock, performs synchronization between the driving clock and a hall sensor signal output from the hall sensor unit, and outputs the synchronized driving clock and the synchronized hall sensor signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     A claim for priority under 35 U.S.C. §119 is made to Korean Patent Application No. 10-2011-0135211 filed Dec. 15, 2011, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     The inventive concepts described herein relate to a home sensor signal generating device. 
     Measurement of rotating angle and speed of a rotor may be needed to control a speed of a motor, in particular, a brushless motor. The rotating angle and speed of the rotor may be measured by an encoder rotated with the rotor or a hall sensor disposed at a stator. 
     A hall sensor may be a magnetic sensor the output of which is varied according to an applied magnetic field. A magnetic field applied to the hall sensor may be varied according to rotation of a magnetic pole for location detection disposed at the rotor. The rotating angle and speed of the rotor may be measured by measuring an output signal of the hall sensor disposed at the stator. The hall sensor may be disposed at the stator with a predetermined interval, and may generate a multiplied pulse signal. It may be necessary to reduce a difference between an output signal of the hall sensor and an internal signal of a motor controller for precise control of a motor speed. 
     SUMMARY 
     One aspect of embodiments of the inventive concept is directed to provide a hall sensor signal generating device comprising a rotor which has a magnetic property and rotates on the basis of a rotary axis; a hall sensor unit which is disposed to be spaced apart from a stator disposed outside the rotor; and a clock synchronization unit which receives a driving clock, performs synchronization between the driving clock and a hall sensor signal output from the hall sensor unit, and outputs the synchronized driving clock and the synchronized hall sensor signal. 
     In example embodiments, the hall sensor signal generating device is included in a Brushless Direct Current (BLDC) motor. 
     In example embodiments, the hall sensor signal generating device is included in a Synchronous Reluctance Motor (SynRM). 
     In example embodiments, the hall sensor unit includes a plurality of hall sensors that are disposed with the same interval. 
     In example embodiments, the plurality of hall sensors includes three hall sensors that are disposed with an interval of 120 degrees. 
     In example embodiments, the hall sensor signal generating device further comprises a clock generating unit which generates an internal driving clock; and a clock controlling unit which receives an external driving clock and a control signal from an external device, selects one of the external driving clock and the internal driving clock according to the control signal, and provides the selected driving clock to the clock synchronization unit. 
     In example embodiments, a frequency of the internal driving clock is variable. 
     In example embodiments, the clock controlling unit further includes a multiplier for multiplying a frequency of the selected driving clock. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The above and other objects and features will become apparent from the following description with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified, and wherein 
         FIG. 1  is a block diagram schematically illustrating a connection structure between a hall sensor signal generating device and an external motor controller according to an embodiment of the inventive concept. 
         FIG. 2  is a timing diagram illustrating output hall sensor signals of a hall sensor signal generating device, input hall sensor signals measured within an external motor controller, and a driving clock of the external motor controller. 
         FIG. 3  is a block diagram schematically illustrating a connection structure between a hall sensor signal generating device and an external motor controller according to another embodiment of the inventive concept. 
         FIG. 4  is a block diagram schematically illustrating a connection structure between a hall sensor signal generating device and an external motor controller according to still another embodiment of the inventive concept. 
         FIG. 5  is a timing diagram illustrating synchronized output hall sensor signals of a hall sensor signal generating device in  FIG. 4 , input hall sensor signals measured within an external motor controller, and a driving clock of the external motor controller. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments will be described in detail with reference to the accompanying drawings. The inventive concept, however, may be embodied in various different forms, and should not be construed as being limited only to the illustrated embodiments. Rather, these embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey the concept of the inventive concept to those skilled in the art. Accordingly, known processes, elements, and techniques are not described with respect to some of the embodiments of the inventive concept. Unless otherwise noted, like reference numerals denote like elements throughout the attached drawings and written description, and thus descriptions will not be repeated. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. 
     It will be understood that, although the terms “first”, “second”, “third”, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the inventive concept. 
     Spatially relative terms, such as “beneath”, “below”, “lower”, “under”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary terms “below” and “under” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the inventive concept. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Also, the term “exemplary” is intended to refer to an example or illustration. 
     It will be understood that when an element or layer is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another element or layer, it can be directly on, connected, coupled, or adjacent to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to”, “directly coupled to”, or “immediately adjacent to” another element or layer, there are no intervening elements or layers present. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
       FIG. 1  is a block diagram schematically illustrating a connection structure between a hall sensor signal generating device and an external motor controller according to an embodiment of the inventive concept. Referring to  FIG. 1 , a hall sensor signal generating device  1  may include a rotor  10 , a first hall sensor  20 , a second hall sensor  21 , and a third hall sensor  22 . In  FIG. 1 , there is exemplarily illustrated the case that a hall sensor signal generating device includes three hall sensors. However, the inventive concept is not limited thereto. The inventive concept may be applied to all hall sensor signal generating devices each having one or more hall sensors. 
     The hall sensor signal generating device  1  may generate a hall sensor signal to output it to an external device, for example, the external motor controller. The hall sensor signal generating device  1  may include a Brushless Direct Current (BLDC) motor or a Synchronous Reluctance Motor (SynRM). 
     The rotor  10  may form a magnetic field through joining of magnets. Magnets of the rotor  10  may be a ring permanent magnet. The rotor  10  may be rotated according to a direction of current applied to a stator of a motor. The rotor  10  may continue to be rotated as a direction of current is periodically varied by a control circuit. 
     The rotor  10  may have a magnetic property, and a magnetic field applied to a stator of a motor may be varied by rotation of the rotor  10 . A location of the rotor  10 , that is, a rotating angle and a speed may be measured by measuring a varied magnetic field. 
     The first to third hall sensors  20  to  22  may be disposed at the stator of the motor with the same interval. In example embodiments, three hall sensors may be disposed with an interval of 120 degrees. If a magnetic field is applied to a hall sensor in a vertical direction, an electric potential perpendicular to a direction of the magnetic field may be generated. As the rotor  10  rotates, each of the first to third hall sensors  20  to  22  may output a square wave pulse signal having a phase difference of 60 degrees. 
     Output hall sensor signals S 1 , S 2 , and S 3  output from the first to third hall sensors  20  to  22  may be provided to the external motor controller. The external motor controller may measure the rotating angle and speed of the rotor  10  using input hall sensor signals S 1 ′, S 2 ′, and S 3 ′ to control a current input to a motor. The external motor controller may be formed of a digital circuit, and may operate in synchronization with a driving clock MC_CLK. A synchronization error among the input hall sensor signals S 1 ′, S 2 ′, and S 3 ′ measured within the external motor controller may be generated when the output hall sensor signals S 1 , S 2 , and S 3  input from the first to third hall sensors  20  to  22  are not synchronized with the driving clock MC_CLK of the external motor controller. 
       FIG. 2  is a timing diagram illustrating output hall sensor signals of a hall sensor signal generating device, input hall sensor signals measured within an external motor controller, and a driving clock of the external motor controller. 
     Referring to  FIG. 2 , output hall sensor signals S 1 , S 2 , and S 3  may be square wave pulse signals, having a phase difference of 60 degrees, output from first to third hall sensors  20  to  22 . Input hall sensor signals S 1 ′, S 2 ′, and S 3 ′ may be the output hall sensor signals S 1 , S 2 , and S 3  which are input within the external motor controller. 
     Within the external clock, the output hall sensor signals S 1 , S 2 , and S 3  may appear in synchronization with the driving clock MC_CLK. Thus, if the output hall sensor signals S 1 , S 2 , and S 3  are not synchronized with the driving clock MC_CLK of the external motor controller, a synchronization error may be generated among the input hall sensor signals S 1 ′, S 2 ′, and S 3 ′. 
     With the above description, the rotating angle and speed measured at the external motor controller may have an error due to synchronization. Thus, it is difficult to control a speed precisely due to an error generated at a motor speed controlling operation. 
       FIG. 3  is a block diagram schematically illustrating a connection structure between a hall sensor signal generating device and an external motor controller according to another embodiment of the inventive concept. Referring to  FIG. 3 , a hall sensor signal generating device  100  may include a rotor  110 , a first hall sensor  120 , a second hall sensor  121 , a third hall sensor  122 , and a clock synchronization unit  130 . 
     The first to third hall sensors  120  to  122  in  FIG. 3  may be configured the same as those in  FIG. 1 . A magnetic field applied to a stator may be varied by rotation of the rotor  110 . The first to third hall sensors  120  to  122  may output square wave output signals having a phase difference of 60 degrees. Output hall sensor signals may be sent to the clock synchronization unit  130 . 
     The clock synchronization unit  130  may receive a driving clock MC_CLK from an external device. The clock synchronization unit  130  may perform synchronization between the driving clock MC_CLK and the output hall sensor signals. The clock synchronization unit  130  may output synchronized output hall sensor signals S 1 , S 2 , and S 3  and a driving clock CLKout. 
     The external motor controller may receive the synchronized output hall sensor signals S 1 , S 2 , and S 3 . The external motor controller may receive the driving clock CLKout synchronized with the output hall sensor signals as a driving clock. Since the output hall sensor signals S 1 , S 2 , and S 3  input from the first to third hall sensors  120  to  122  are synchronized with the driving clock CLKout, no synchronization error may be generated. 
     The hall sensor signal generating device  100  may output a hall sensor signal and a driving clock synchronized with the hall sensor signal. The external motor controller may use a driving clock output from the hall sensor signal generating device  100  as a driving clock of a digital circuit. Thus, a synchronization error may not be generated when the external motor controller receives a hall sensor signal. 
       FIG. 4  is a block diagram schematically illustrating a connection structure between a hall sensor signal generating device and an external motor controller according to still another embodiment of the inventive concept. Referring to  FIG. 4 , a hall sensor signal generating device  200  may include a rotor  210 , a first hall sensor  220 , a second hall sensor  221 , a second hall sensor  222 , a clock generating unit  230 , a clock controlling unit  240 , and a clock synchronization unit  250 . 
     The first to third hall sensors  220  to  222  in  FIG. 4  may be configured the same as those in  FIG. 3 . A magnetic field applied to a stator may be varied by rotation of the rotor  210 . The first to third hall sensors  220  to  222  may output square wave output signals having a phase difference of 60 degrees. Output hall sensor signals may be sent to the clock synchronization unit  250 . 
     The clock generating unit  230  may generate an internal driving clock. A frequency of the internal driving clock generated by the clock generating unit  230  may be variable. The clock generating unit  230  may provide the internal driving clock to the clock controlling unit  240 . 
     The clock controlling unit  240  may receive the internal driving clock from the clock generating unit  230 . The clock controlling unit  240  may receive an external driving clock MC_CLK and a control signal from an external device. Whether a driving clock to be used for synchronization is the internal clock signal or the external clock signal may be determined according to the control signal. 
     The clock controlling unit  240  may include a multiplier. The multiplier may multiply a selected driving clock to adjust a frequency of a driving clock. The clock controlling unit  240  may provide the clock synchronization unit  250  with the selected driving clock (or, in the event that a multiplier is used, a driving clock the frequency of which is adjusted through the multiplier). 
     The clock synchronization unit  250  may perform synchronization between the input driving clock and an output hall sensor signal. The clock synchronization unit  250  may output synchronized output hall sensor signals S 1 , S 2 , and S 3  and a driving clock CLKout. 
     Since the control signal and the external driving clock provided to the hall sensor signal generating device  200  are square wave pulse signals, an input interface of the hall sensor signal generating device  200  may be a digital interface. Also, since the output hall sensor signal and the driving clock output from the hall sensor signal generating device  200  are square wave pulse signals, an output interface of the hall sensor signal generating device  200  may be a digital interface. 
     The external motor controller may receive the synchronized output hall sensor signals S 1 , S 2 , and S 3 . Also, the external motor controller may receive the driving clock synchronized with the output hall sensor signal as a driving clock. Since the output hall sensor signals S 1 , S 2 , and S 3  input from the first to third hall sensors  220  to  222  are synchronized with the driving clock CLKout, no synchronization error may be generated. 
     As described above, the hall sensor signal generating device  200  may output a hall sensor signal and a driving signal synchronized with the hall sensor signal. The driving clock can be an internally generated driving clock or a feedback signal of an externally provided driving clock. The external motor controller may use a driving clock output from the hall sensor signal generating device  200  as a driving clock of a digital circuit. Thus, a synchronization error may not be generated when the external motor controller receives a hall sensor signal. 
       FIG. 5  is a timing diagram illustrating synchronized output hall sensor signals of a hall sensor signal generating device in  FIG. 4 , input hall sensor signals measured within an external motor controller, and a driving clock of the external motor controller. 
     Referring to  FIG. 5 , synchronized output hall sensor signals may be square wave pulse signals that are synchronized after output from first to third hall sensors  220  to  223  and have a phase difference of 60 degrees. Input hall sensor signals S 1 ′, S 2 ′, and S 3 ′ may be the synchronized output hall sensor signals that are provided within an external motor controller. 
     Within the external clock, the synchronized output hall sensor signals may appear in synchronization with a driving clock of the external motor controller. 
     Referring to a hall sensor signal generating device in  FIG. 1 , an output hall sensor signal may be synchronized with a driving clock of the external motor controller. Unlike the hall sensor signal generating device in  FIG. 1 , if a hall sensor signal generating device in  FIG. 4  is used, no synchronization error may be generated among input hall sensor signals S 1 &#39;, S 2 ′, and S 3 ′ measured within the external motor controller. 
     It is possible to control a motor speed more precisely by removing a synchronization error caused when the external motor controller measures rotating angle and speed of a rotor. 
     The inventive concept may be modified or changed variously. For example, a rotor, a hall sensor, a clock generating unit, a clock controlling unit, and a clock synchronization unit may be changed or modified variously according to environment and use. 
     While the inventive concept has been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. Therefore, it should be understood that the above embodiments are not limiting, but illustrative.