Abstract:
In accordance with these and other embodiments of the present disclosure, a system and method include supplying, by a single boost converter, power to a first circuit that provides a circuit operation and power to a second circuit that provides another circuit operation. The system and method also include receiving, by a controller coupled to the single boost controller, an operating condition signal indicative of at least one of: (i) a power delivered by the single boost converter, and (ii) a temperature of the single integrated circuit. The system and method further include allocating, by the controller, power deliverable by the single boost converter between the first circuit and second circuit in response to the operating condition signal.

Description:
RELATED APPLICATION 
     The present disclosure claims priority to U.S. Provisional Patent Application Ser. No. 61/645,125, filed May 10, 2012, which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure generally relates to an integrated circuit, and, more particularly, to using a single boost converter in a single integrated circuit that supplies power to two or more separate operational or functional circuits in the single integrated circuit. 
     BACKGROUND 
     Many mobile phones on the market today provide phone functionality and also have a built in camera with flash capability in order to take higher quality photos. These phones may require circuitry that enables audio functionality for the phone and the flash capability. Audio functionality for a mobile phone is not just limited to the phone functionality but can also include the audio functionality for playing music, games, and videos and running applications and programs. 
     The camera flashes on mobile phones often use light emitting diode (LED) flash drivers to enable flash capability. The majority of these flashes for mobile phones are enabled through a boosted LED flash driver (e.g., having a boost converter). The boost converter is used for powering the LED driver and works to provide a constant current source. Generally, the flash driver uses a boost converter that works as a constant current source wherein the flash driver is enabled using hardware pins and is configurable via an I 2 C interface. Such an exemplary LED flash driver is disclosed in Analogic Tech Product Datasheet MT 1271 for 1.5 A Step-Up Current Regulator for Flash LED dated April 2009. 
     Also, mobile phones on the market today often use a boosted audio amplifier for higher and louder audio quality. A boosted audio amplifier comprises a boost converter powering an audio amplifier. By boosting the audio amplifier, the sound output of the amplifier may be increased and made louder. In addition, by boosting the voltage to a higher voltage level, the sound output may not be clipped by the battery voltage threshold because the audio amplifier will not be limited to the voltage supplied by the battery. 
     Different types of audio amplifiers exist. Such types of amplifiers include but are not limited to Class D, H, A, B, and A-B amplifiers. A boosted class-D amplifier may deliver a higher output power independent of the battery voltage because the boost can guarantee constant delivery of power to the audio amplifier. When a boost converter is used for powering a class-D amplifier, the boost converter works to provide a constant voltage source to the audio amplifier. In another case, a class-H scheme is implemented to maximize the boost converter efficiency by varying the boost output voltage at a certain signal level. At each respective signal level, the boost converter works to provide a corresponding constant voltage source. One disadvantage of the powering scheme for a boosted Class-D amplifier is that the overall system cost and size increase due to the requirements of additional components related to operating the boost converter with the audio amplifier. 
     Because both the LED flash driver and the audio amplifier require a similar or same type of boost converter, there is a desire and need for both the LED flash driver and audio amplifier to be supplied by a single boost converter. 
       FIG. 1  depicts an exemplary block diagram of an LED flash driver and audio amplifier power supply in accordance with the prior art in which a single boost converter is used to simultaneously drive both the LED flash driver and audio amplifier power supply. Such an exemplary circuit implementation is disclosed in Texas Instruments Datasheet for TPS61300, TPS61301, TPS61305 entitled “1.5 A/4.1 A Multiple LED Camera Flash Driver with 12CTM Compatible Interface” dated June 2009 and revised September 2010. Referring to  FIG. 1 , a constant DC voltage supply  102  may be coupled to a capacitor  104  and an inductor  106 . Moreover, the inductor  106  may be coupled to an integrated circuit (“IC”)  108  that comprises a single boosted LED driver and controller. The boosted LED flash driver IC  108  may drive the LED flash light using another capacitor  110  and diodes  112 ,  114 . The LED flash driver IC  108  may also drive an audio amplifier  124 . The audio amplifier  124  may comprise a Class-D amplifier  120 , two audio inputs  116 ,  118  and a speaker system  122  that outputs an audio signal. Control of LED flash driver IC  108  and audio amplifier  124  may be provided at the board level. Such control at the board level may be provided through system software that uses a General Purpose Input/Output (GPIO) port of the LED flash driver IC  108 , or an I 2 C interface. Such control may involve the exclusive operation of either the LED flash driver IC  108  or audio amplifier  124 , or operating the LED flash driver IC  108  and the audio amplifier  124  simultaneously. When operating simultaneously, the control may include reducing the gain of the audio amplifier  124 . Because the audio amplifier  124  is external to the controller in LED flash driver IC  108 , the audio signal level may not be monitored before the LED flash is turned on. Thus, the gain amount of the audio signal that needs to be attenuated is hard to determine, and in most cases, due to the high crest factor of music contents, a need to reduce audio gain may not even exist. Thus, the controller for the LED flash driver  108  may be limited to being used to control the audio amplifier  124 . 
     Therefore, it may be desirable to provide a way to control both the LED flash driver and the audio amplifier by using a controller that is on a single integrated circuit. Such a solution is disclosed in U.S. Utility patent application Ser. No. 13/548,963 filed Jul. 13, 2012, and entitled “Chip Level Integration of a Boosted Class-D Amplifier and Integrated LED Flash Driver,” which is incorporated by reference herein in its entirety. 
     When a boost converter system is used to deliver power to multiple loads, a number of problems may occur due to limited battery capacity, inductor saturation, over-heating, and power delivery limitations of the boost converter. Traditional solutions typically focus on electrical overload protection by limiting the current of the boost converter or over-temperature protection by disabling the boost converter. With such solutions, typically no on-chip management of the boost converter load is attempted in order to maintain regulated operation within its maximum deliverable power and within its desired temperature range. Accordingly, it may be desirable to allow a user a choice to optimize audio quality, LED flash current, or both, and allocate power between boosted components based on such user preferences. 
     SUMMARY 
     In accordance with the present disclosure, disadvantages and problems associated with power budgeting in an integrated boost converter power system may be reduced or eliminated. 
     In accordance with embodiments of the present disclosure, a single integrated circuit may include a single boost converter, a first circuit that provides a circuit operation and is coupled to the single boost converter, a second circuit that provides another circuit operation and is coupled to the single boost converter, and a controller coupled to the single boost controller. The single boost converter may supply power to the first circuit and the second circuit. The controller may be configured to receive an operating condition signal indicative of at least one of: (i) a power delivered by the single boost converter; and (ii) a temperature of the single integrated circuit. In response to the operating condition signal, the controller may allocate power deliverable by the single boost converter between the first circuit and the second circuit. 
     In accordance with these and other embodiments of the present disclosure, a method may include supplying, by a single boost converter, power to a first circuit that provides a circuit operation and power to a second circuit that provides another circuit operation. The method may also include receiving, by a controller coupled to the single boost controller, an operating condition signal indicative of at least one of: (i) a power delivered by the single boost converter; and (ii) a temperature of the single integrated circuit. The method may further include allocating, by the controller, power deliverable by the single boost converter between the first circuit and second circuit in response to the operating condition signal. 
     Technical advantages of the present disclosure may be readily apparent to one skilled in the art from the figures, description and claims included herein. The objects and advantages of the embodiments will be realized and achieved at least by the elements, features, and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the claims set forth in this disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a block diagram of an example LED flash driver and audio amplifier power supply in which a single boost converter is used to simultaneously drive both the LED flash driver and audio amplifier power supply, as is known in the art; 
         FIG. 2  illustrates a block diagram of an exemplary single integrated circuit that uses a single boost converter in the single integrated circuit that supplies power to two or more separate operational or functional circuits, such as an LED flash driver and an audio amplifier, in the single integrated circuit, in accordance with embodiments of the present disclosure; 
         FIG. 3  illustrates a more detailed block diagram of an LED flash driver to which the single boost converter in the single integrated circuit supplies power, in the single integrated circuit, in accordance with embodiments of the present disclosure; and 
         FIG. 4  illustrates a flow chart of an exemplary method for controlling power delivery from a single boost converter in a single integrated circuit to an LED flash driver and an audio amplifier in the single integrated circuit, in accordance with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 2  illustrates a block diagram of an exemplary single integrated circuit (“IC”)  200  that uses a single boost converter  202  in the IC  200  that supplies power to two or more separate operational or functional circuits, such as an LED flash driver  204  and an audio amplifier  206 , in the IC  200 , in accordance with embodiments of the present disclosure. LED flash driver  204  may provide LED flash driver circuit operations, and audio amplifier  206  may provide audio amplification circuit operations. Single IC  200  comprises a controller  208  coupled to single boost converter  202 , LED flash driver  204 , and audio amplifier  206 . The single boost converter  202  may be configured to drive both the LED flash driver  204  and audio amplifier  206 , wherein the LED flash driver  204  requires a constant current in order to drive the LED flash and the audio amplifier  206  requires a constant voltage to operate. As shown in  FIG. 2 , boost converter  202  may receive an external boost converter limit setting Ilimit_set signal  203  (e.g., a setting regarding a maximum operating current, maximum operating power, or other maximum operating parameter of boost converter  202 ). In addition or alternatively, boost converter  202  may receive a reference control signal Vbst_ref_ctrl  234  (e.g., a control signal indicative of an output voltage level V bst  to be generated by boost converter  202  in order to drive LED driver  204  and/or audio amplifier  206 ). Based on limit_set signal  203  and/or Vbst_ref ctrl signal  234 , boost converter  202  may generate output voltage V bst . In addition or alternatively, boost converter  202  may output an operating condition signal reach_boost_limit  232  indicative of the power delivered by boost converter  202  to LED flash driver  204 , audio amplifier  206 , and/or other components of IC  200 . In some embodiments, boost_reach_limit signal  232  may be indicative of an aggregate power consumption of the LED flash driver  204  and the audio amplifier  206 . In these and other embodiments, reach_boost_limit signal  232  may be indicative of whether the power delivered by boost converter  202  exceeds a threshold power level (e.g., a power limit of boost converter  202  as given by Ilimit_set signal  203 ). 
     Controller  208  may be coupled to all three blocks of IC  200  that enables both LED flash and audio capability. As shown in  FIG. 2 , controller  208  may receive one or more external operational mode signal, such as is_audio_reduce_allowed signal  209  (e.g., an audio volume reduction setting regarding whether the controller is permitted to reduce an audio volume for audio amplifier  206  below an audio volume setting), is_led_reduce_allowed signal  210  (e.g., a current reduction setting regarding whether the controller is permitted to reduce a current for LED flash driver  204  below a current setting), LED_current_setting  211  (e.g., a current setting for LED flash driver  204 ), and audio_volume_setting  212  (e.g., a volume setting for audio amplifier  206 ). In addition or alternatively, controller  208  may receive an operating condition signal is_thermal_flag  213  indicative of a temperature of the single integrated circuit. In some embodiments, operating condition signal is_thermal_flag  213  may be indicative of whether the temperature of the single integrated circuit exceeds a threshold temperature level. In addition or alternatively, controller  208  may also receive operating condition signal reach_boost_limit  232 . 
     As depicted in  FIG. 2 , LED flash driver  204  may be supplied with boosted power from boost converter  202  that is set by controller  208  in order to maintain constant current for LED flash driver  204  to operate its flash capability.  FIG. 3  illustrates a more detailed block diagram of LED flash driver  204 , in accordance with embodiments of the present disclosure. LED flash driver  204  may receive a control input signal LED_current_control  216  from controller  208  and may forward control input signal  216  from controller  208  to a current source  218 . Current source  218  may be configured to adjust and set the current accordingly using the ratio systematic implementation of two field effect transistors (“FETs”). Once the current has been adjusted to drive the LED flash diode  226 , a real time voltage at the output of the LED flash diode  226  may be fed back to controller  208  through feedback voltage signal Vds_sense  228 . This real time feedback voltage signal  228  may factor in and account for different forward voltage drops of the flash being used (e.g., the forward voltage drops of LED flash diode  226 ). Thus, controller  208  may, based on one or more operational mode signals (e.g., is_led_reduce_allowed signal  210 , LED_current_setting signal  211 ), one or more operating condition signals (e.g., reach_boost_limit signal  232 , is_thermal_flag signal  213 ), and/or feedback voltage signal Vds_sense  228 , generate LED_current_control signal  216  in order to control the current of LED flash driver  204 , thus controlling the power consumption of LED flash driver  204 , as described in greater detail elsewhere in this disclosure. 
     As shown in  FIG. 2 , audio Class D amplifier  206  may be supplied with boosted power from boost converter  202  that is set by controller  208  in order to maintain constant voltage for the audio amplifier  206  to maintain operations. Controller  208  may, based on one or more operational mode signals (e.g., is_audio_reduce_allowed signal  209 , audio_volume_setting signal  212 ), one or more operating condition signals (e.g., reach_boost_limit signal  232 , is_thermal_flag signal  213 ), and/or feedback voltage signal Vds_sense  228 , generate audio_volume_control signal  217  in order to control the audio volume for audio amplifier  206 , thus controlling the power consumption of audio amplifier  206 , as described in greater detail elsewhere in this disclosure. 
     In operation, controller  208  may, in response to one or more operating condition signals (e.g., reach_boost_limit signal  232 , is_thermal_flag signal  213 ) and one or more operation mode signals (e.g., is_audio_reduce_allowed signal  209 , is_led_reduce_allowed signal  210 , LED_current_setting signal  211 , audio_volume_setting signal  212 ), allocate power deliverable by boost converter  202  between LED flash driver  204  and audio amplifier  206 . For example, if boost_reach_limit signal  232  indicates that power delivered by boost converter  202  exceeds a threshold power level (e.g., defined by Ilimit_set signal  203 ), controller  208  may generate one or more appropriate signals for LED_current_control signal  216  and/or audio_volume_control signal  217  in order to reduce the individual power consumption of at least one of the flash LED driver  204  and the audio amplifier  206 . As another example, if is_thermal_flag signal  213  indicates that an over-temperature condition exists associated with IC  200 , controller  208  may generate one or more appropriate signals for LED_current_control signal  216  and/or audio_volume_control signal  217  in order to reduce the individual power consumption of at least one of flash LED driver  204  and audio amplifier  206 . In both examples (e.g., power exceeding threshold power level, over-temperature condition), controller  208  may determine whether to reduce the individual power consumption of flash LED driver  204 , audio amplifier  206 , or both, based on operation mode signals (e.g., is_audio_reduce_allowed signal  209 , is_led_reduce_allowed signal  210 ) indicative of whether either the current for LED flash driver  204  or the volume of audio amplifier  206  may be reduced below their respective current and volume settings. 
     In conditions in which power delivered by boost converter  202  does not exceed its limit and no over-temperature condition exists, controller  208  may allocate power deliverable by boost converter  202  in accordance with operation mode signals (e.g., LED_current_setting signal  211 , audio_volume_setting signal  212 ) indicative of desired operating parameters of LED flash driver  204  and/or audio amplifier  206 . 
       FIG. 4  illustrates a flow chart of an exemplary method  400  for controlling power delivery from single boost converter  202  in single IC  200  to LED flash driver  204  and audio amplifier  206  in single IC  200 , in accordance with embodiments of the present disclosure. According to certain embodiments, method  400  may begin at step  402 . As noted above, teachings of the present disclosure may be implemented in a variety of configurations of IC  200 . As such, the preferred initialization point for method  400  and the order of the steps  402 - 410  comprising method  400  may depend on the implementation chosen. 
     At step  402 , boost converter  202  may be enabled to generate a boosted voltage for flash LED driver  204  and/or audio amplifier  206 . During such process, the current of flash LED driver  204  and volume of audio amplifier  206  may be set to desired values in accordance with operation mode signals (e.g., LED_current_setting signal  211 , audio_volume_setting signal  212 ). 
     At step  404 , controller  208  may determine values of vds_sense signal  228  and operating condition signals (e.g., reach_boost_limit signal  232 , is_thermal_flag signal  213 ) in order to determine whether to reduce boost voltage V bst , reduce current of flash LED driver  204 , and/or reduce volume of audio amplifier  206 . If it is determined that vds_sense signal  216  is below a threshold level (e.g., 0.5 volts) and the volume of audio amplifier  206  is below a threshold level, boost may be reduced and method  400  may proceed to step  406 . If it is determined that delivery of power by boost converter  202  has reached its limit (e.g., as indicated by reach_boost_limit signal  232 ), that an over-temperature condition has occurred (e.g., as indicated by is_thermal_flag signal  213 ), or that the vds_sense signal  216  is below a threshold level (e.g., 0.3 volts, potentially indicating that flash LED driver  204  is not sinking or sourcing adequate current), method  400  may proceed to step  408  and/or step  410 . If one or more of the foregoing conditions exists, and audio amplifier  206  volume reduction is allowed (e.g., as indicated by is_audio_reduce_allowed signal  209 ), method  400  may proceed to step  408 . If one or more of such conditions exist, and reduction of current of flash LED driver  204  is allowed, method  400  may proceed to step  410  in which the current of flash LED driver  204  is reduced. If none of the applicable conditions exist, method  400  may remain at step  404  until such conditions occur. 
     At step  406 , in response to a determination that vds_sense signal  216  is below a threshold level (e.g., 0.5 volts) and the volume of audio amplifier  206  is below a threshold level, controller  208  may reduce boost voltage V bst  by communicating an appropriate Vbst_ref ctrl signal  234  to boost converter  202 . After completion of step  406 , method  400  may proceed again to step  404 . 
     At step  408 , in response to a determination that delivery of power by boost converter  202  has reached its limit, that an over-temperature condition has occurred, or that the vds_sense signal  216  is below a threshold level, and that audio amplifier  206  volume reduction is allowed, controller  208  may reduce the audio volume of audio amplifier  206  by communicating an appropriate audio_volume_control signal  217  to audio amplifier  206 . After completion of step  408 , method  400  may proceed again to step  404 . 
     At step  410 , in response to a determination that delivery of power by boost converter  202  has reached its limit, that an over-temperature condition has occurred, or that the vds_sense signal is below a threshold level, and that flash LED driver  204  current reduction is allowed, controller  208  may reduce the current of flash LED driver  204  by communicating an appropriate LED_current_control signal  216  to flash LED driver  204 . After completion of step  410 , method  400  may proceed again to step  404 . 
     Although  FIG. 4  discloses a particular number of steps to be taken with respect to method  400 , method  400  may be executed with greater or lesser steps than those depicted in  FIG. 4 . In addition, although  FIG. 4  discloses a certain order of steps to be taken with respect to method  400 , the steps comprising method  400  may be completed in any suitable order. For example, if the appropriate conditions exist, both steps  408  and  410  may be executed substantially contemporaneously. 
     Method  400  may be implemented using IC  200 , components thereof, and/or any other system operable to implement method  400 . In certain embodiments, method  400  may be implemented partially or fully in software and/or firmware embodied in computer-readable media. 
     This disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. 
     All examples and conditional language recited herein are intended for pedagogical objects to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are construed as being without limitation to such specifically recited examples and conditions. Although embodiments of the present inventions have been described in detail, it should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the disclosure.