Power supply unit with auxiliary boost control in bootloader mode

Abstract

The technology described herein relates to a DC input power supply device having an auxiliary boost control circuit (or controller) that facilitates continuous supply of power to a standby output load of the power supply device in a boot loading mode. More specifically, the auxiliary boost circuit (or controller) is configured to take control of a primary power boost stage from a primary controller in a boot loading mode, so that the power supply device can continue to supply power to a standby output with protection functions, regardless of the state of the power supply device or the primary controller.

Description

Technical Field

[0001] Aspects of the present disclosure relate to the field of power supply units, and in particular, to a direct current (DC) input switch mode power supply unit with auxiliary boost control to facilitate continuous supply of power to a standby output load during a bootloader mode. Background Art

[0002] A switch-mode power supply (or switching power converter) is an electronic power supply that contains a switching regulator to efficiently convert electrical power. Like other power supplies, a switch-mode power supply transfers power from a direct current (DC) source or an alternating current (AC) source to a DC load, such as, for example, a personal computer, a server computer, a cloud computing platform, data center equipment, etc., while converting voltage and current characteristics. Unlike a linear power supply, the transfer transistor of a switch-mode power supply is constantly switched between a low-dissipation, full-on state and a full-off state to minimize wasted energy. Voltage regulation is achieved by varying the ratio of the on-to-off time (also called the duty cycle).

[0003] Switched mode power supplies can be used to supply power to a load over a wide range. In other words, a load may require a relatively large amount of power in a "normal" operating mode, whereas the load may require relatively less power during a "standby" operating mode. For example, an LCD flat panel television receiver may require 350 watts of operating power during normal operation, but may only draw a nominal amount of power (e.g., 1 or 2 watts) in a standby mode (i.e., when the LCD flat panel television is "turned off" to keep the remote control circuitry active, etc.).

[0004] One or more controllers (e.g., microcontrollers) are often used to regulate the switch mode power supply, for example, to maintain a constant output voltage. In practice, switch mode power supplies often employ digital controllers that monitor the current drawn by the load and increase or decrease the switch duty cycle as the power output requirements change. Digital control is more popular than analog control because of many advantages, such as, for example, flexibility, ease of control redesign and integration, reduced number of components and reduced cost. Although digital control redesign is possible, implementing the redesign requires boot loading. A boot loader (or boot loader) is a piece of code that allows the user application code to be updated through a communication interface, such as, for example, I2C, UART, etc.

[0005] Unfortunately, today's switch-mode power supplies often do not support continuous supply of power to the standby output load during the boot-loading mode because there is no regulation for the boost stage during the boot-loading mode and the power supplies often do not function well with low input voltages. As a result, the boot-loader is prone to fail or otherwise cause output load disruption. Summary of the invention

[0006] Among other benefits, one or more embodiments described herein address one or more of the foregoing or other problems in the art by providing systems, methods, and non-transitory computer-readable media for continuously supplying power to a standby output of a microcontroller-based switch-mode power supply device while in a bootloader mode.

[0007] In some embodiments, the described technology includes a power supply device, the power supply device including: an input, the input configured to receive a DC input voltage from a voltage source; a main output, the main output configured to supply a predetermined DC output voltage to a load; and a backup output, the backup output configured to supply a nominal DC output voltage to the load. The power supply device also includes a filter, a boost stage circuit, a primary controller, a boost auxiliary circuit, a buck stage circuit, a secondary controller, and a bias module. The filter is coupled to the input and is configured to reduce electromagnetic interference (EMI) in the input voltage. The boost stage circuit is coupled to the filter and is configured to adjust the output of the filter to a step up of a minimum threshold voltage based on a boost regulator signal. The primary controller is coupled to the boost stage circuit and is configured to control the boost regulator signal. The boost auxiliary circuit is coupled to the primary controller and is configured to assume control of the boost regulator signal during a boot loading mode. The buck stage circuit is coupled to the boost stage circuit and is configured to adjust the output voltage of the boost stage circuit to a predetermined DC output voltage based on a buck regulator signal. The secondary controller is coupled to the buck stage circuit and is configured to control the buck regulator signal. The bias module is coupled to the boost stage circuit and is configured to adjust the output voltage of the boost stage circuit to a nominal DC output voltage.

[0008] In some embodiments, the described technology includes a method for continuously supplying power to a standby output of a power supply device in a boot loading mode. The method includes: receiving a direct current (DC) input voltage from a voltage source through an input port of the power supply device; filtering the input voltage through an electromagnetic interference (EMI) filter; and driving a boost regulator signal through a primary controller of the power supply to control regulation through a boost stage circuit. The method also includes: regulating a boost of the filtered input voltage to a minimum threshold voltage based on the boost regulator signal through the boost stage circuit; asserting a boot loading signal through the primary controller in response to receiving a request to enter the boot loading mode; and assuming control of driving the boost regulator signal through a boost auxiliary circuit coupled to the primary controller in the boot loading mode to continuously supply power to the standby output of the power supply device in response to detecting the assertion of the boot loading signal.

[0009] In some embodiments, the described technology includes an auxiliary boost control circuit for a low voltage direct current (LVDC) input power supply device. The auxiliary boost control circuit includes means for monitoring the validity of a bootstrap load signal in an idle state, wherein the bootstrap load signal indicates that a primary controller of the power supply device is entering a bootstrap load mode. The auxiliary boost control circuit also includes means for causing the auxiliary boost control circuit to transition from the idle state to an auxiliary protection state in response to the validity of the bootstrap load signal, wherein the auxiliary boost control circuit is configured to assume control of a boost regulator signal for controlling regulation of a boost stage circuit to boost an input to a minimum threshold voltage.

[0010] Additional features and advantages of the present application will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of such example embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to describe the manner in which the above and other advantages and features can be obtained, a more specific description is set forth and will be presented by reference to specific embodiments thereof illustrated in the accompanying drawings. It should be understood that these drawings depict only typical embodiments and are not to be considered as limiting the scope thereof. The embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings.

[0012] Figure 1 Depicted is a block diagram illustrating an example power supply apparatus including an auxiliary boost controller for assuming control of a primary power boost stage during a bootloading mode, in accordance with some embodiments.

[0013] Figure 2Depicted is a block diagram illustrating example components of a primary controller in the form of a microcontroller in accordance with some embodiments.

[0014] Figure 3 Depicted is a flow chart illustrating an example process for entering and exiting bootloader mode in accordance with some implementations.

[0015] Figure 4 Depicted is a flow chart illustrating an example process for operating an auxiliary boost controller to assume control of regulation of a primary power boost stage, according to some implementations.

[0016] Figure 5 Depicted is a state diagram illustrating example operation of an auxiliary boost controller according to some implementations.

[0017] Figure 6 Depicted are example signaling that occurs between various components of a power supply device during a transition from a "normal" (or non-bootloading) operating mode to a bootloading mode and back again, in accordance with some embodiments.

[0018] Figure 7 Depicted is a flow chart illustrating an example process for continuously supplying power to a standby output of a power supply device in a bootloader mode in accordance with some implementations.

[0019] Figure 8 Depicted are example waveforms illustrating intermediate voltage measurements of a power supply apparatus entering a bootloading mode without auxiliary boost control in accordance with some embodiments.

[0020] Fig.9A and Fig. 9B Depicted are example waveforms illustrating intermediate voltage measurements of a power supply device entering and exiting a bootloader mode with auxiliary boost control according to some embodiments.

[0021] The drawings are not necessarily drawn to scale. Similarly, for the purpose of discussing some embodiments of the present technology, some components and / or operations may be divided into different blocks or combined into a single block. In addition, although the technology can be modified into various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. However, it is not intended to limit the technology to the specific embodiments described. On the contrary, the technology is intended to cover all modifications, equivalents and substitutes that fall within the scope of the technology defined by the appended claims. DETAILED DESCRIPTION

[0022] Example embodiments are provided so that the present disclosure will be thorough and will fully convey the scope to those skilled in the art. Many specific details, such as embodiments of specific components, devices, and methods, are set forth to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and should not be construed as limiting the scope of the present disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known techniques are not described in detail.

[0023] The terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. As used herein, the singular forms "a", "an", and "the" may also be intended to include plural forms unless the context clearly indicates otherwise. The terms "comprises", "comprising", "including", and "having" are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups thereof. The method steps, processes, and operations described herein are not to be interpreted as necessarily requiring them to be performed in the specific order discussed or illustrated, unless explicitly identified as an execution order. It should also be understood that additional steps or alternative steps may be adopted.

[0024] Although the term first, second, third etc. can be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or part from another region, layer or part. Terms such as "first", "second" and other numerical terms do not imply an order or sequence when used in this article, unless the context clearly indicates. Therefore, without departing from the teaching of the example embodiment, the first element, component, region, layer or part discussed below can be referred to as the second element, component, region, layer or part.

[0025] For ease of description, spatially relative terms such as "inside", "outside", "below", "below", "lower", "above", "upper", etc. may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the drawings. In addition to the orientation depicted in the drawings, spatially relative terms may be intended to include different orientations of the device in use or operation. For example, if the device in the drawings is flipped, the elements described as being "below" or "below" other elements or features will be oriented to be "above" the other elements or features. Therefore, the example term "below" may include both an orientation of "above" and an orientation of "below". The device may be oriented in other ways (rotated 90 degrees or in other orientations) and the spatially relative descriptions used herein may be interpreted accordingly.

[0026] As described above, one or more digital controllers, such as microcontrollers, are often used to regulate the switch mode power supply, for example, to maintain a constant output voltage. In addition, it is necessary to implement a boot loader to achieve any redesign of the digital control. Unfortunately, today's switch mode power supplies often do not support continuous supply of power to the standby output load during the boot loading mode, because there is no regulation for the boost stage during the boot loading mode and the power supply often does not function well with low input voltages. Therefore, the boot loader is prone to fail or otherwise cause an output load interruption.

[0027] The technology described herein relates to a DC input power supply device having an auxiliary boost control circuit (or controller) that facilitates continuous supply of power to a standby output load of the power supply device in a boot loading mode. More specifically, the auxiliary boost circuit (or controller) is configured to take control of a primary power boost stage from a primary controller in a boot loading mode, so that the power supply device can continue to supply power to a standby output with protection functions, regardless of the state of the power supply device or the primary controller.

[0028] Figure 1 A block diagram illustrating an example power supply device 100 including an auxiliary boost controller 118 for assuming control of a primary power boost stage 114 during a boot loading mode is depicted according to some embodiments. More specifically, the auxiliary boost controller 118 is configured to assume control of the primary power boost stage 114 to support supplying a backup output 132 to a load (not shown) when the primary controller 116 is in the boot loading mode. Figure 1In the embodiment shown in FIG. 1 , the power supply device 100 is a low voltage DC input switch mode power supply (SMPS). However, it should be understood that the power supply device 100 may be any power supply that continuously supports a standby output to a load in a boot loading mode.

[0029] like Figure 1 In the embodiment shown in FIG. 1 , the power supply device 100 includes a two-stage cascade topology (boost to buck) boost-buck converter. More specifically, the initial boost stage allows the passage of a voltage input greater than a minimum threshold voltage, or increases the input voltage to the minimum threshold voltage using its boost capability. The buck stage then takes the increased (or boosted) voltage levels from the initial boost stage and converts them to a stable predetermined output voltage.

[0030] The power supply device 100 includes a primary power circuit 110 and a secondary power circuit 120. The primary power circuit 110 includes a DC input 105, an electromagnetic interference (EMI) filter 112, a primary power boost stage 114, a primary controller 116, and an auxiliary boost controller 118. The secondary power circuit 110 includes a bias module 122, a secondary power buck stage 124, and a secondary controller 126. Other components, modules, or controllers are also possible.

[0031] In operation, the power supply device 100 receives a DC input 105 and feeds the DC input 105 to an EMI filter 112. The EMI filter 112 is configured to filter the DC input 105 to an acceptable predetermined level. The problem with EMI is that if the amount of radiated EMI does not meet the electromagnetic compatibility standard, EMI can cause failure of electronic equipment, erroneous activation of protection equipment, or inaccurate operation of radar and telecommunication equipment. Therefore, sufficient filtering is necessary to ensure the quality of the power supply device 100. Switching mode power supplies, inverters, and generally all power electronic devices are sources of EMI. In fact, most electrical and electronic equipment generates EMI when switching of current occurs. In some embodiments, EMI can take the form of conducted EMI, i.e., noise propagated through electrical conductors, wires, and components. EMI can also be manifested as radiated EMI, which is noise propagated through the air in the form of a magnetic field or radio waves. The output of the EMI filter 112 is fed to the primary power boost stage 114.

[0032] The primary power boost stage 114 boosts (or increases) the output of the EMI filter 112 to a minimum threshold voltage. Figure 1In the embodiment shown in FIG. 1 , the boost (or increase) is regulated by the boost control signaling 115 provided by the primary controller 116 during the "normal" (or non-bootloading) operating mode and by the boost control signaling 115 provided by the auxiliary boost controller 118 during the bootloading mode. As discussed herein, a bootloader is a piece of code that allows the user application code to be updated through a communication interface, such as, for example, I2C, UART, etc. When the primary controller 116 is performing a bootloading operation, the power supply device 100 is said to be in the bootloading mode. Therefore, the boost control signaling 115 is driven by the primary controller 116 during the "normal" (or non-bootloading) operating mode and by the auxiliary boost controller 118 during the bootloading mode.

[0033] The primary controller 116 may be a microcontroller or any digital circuitry configured to monitor the output V bulk , and in turn regulates the primary power boost stage 114 via boost control signaling 115 during a "normal" (or non-bootloading) mode of operation. During the "normal" (or non-bootloading) mode of operation, the primary controller 116 provides digital control of the primary power boost stage 114. As discussed herein, there are many advantages to digital control over analog control, including, but not limited to, flexibility, ease of control redesign, ease of integration, component reduction, component cost reduction, etc. However, it is necessary to implement a bootloader when the digital control is redesigned, and the primary controller 116 is unable to regulate the primary power boost stage 114 when the bootloader is implemented, i.e., during the bootloading mode. During the bootloading mode, the primary controller 116 asserts a bootload signal (not shown) to indicate that the primary controller 116 is in the bootloading mode. Reference Figure 3 An embodiment illustrating the operation of the primary controller 116 to enter and then exit the bootloader mode is shown and discussed in more detail. Figure 2 An example primary controller 200 is shown and discussed in further detail.

[0034] The auxiliary boost controller 118 may be a microcontroller or digital or analog circuit configured to assume control of regulating the primary power boost stage 114 via the boost control signaling 115 during the bootloading mode to continuously supply power to the backup output 132. Figure 1 Not shown in the embodiment of FIG. 1 , in some implementations, the primary controller 116 and the auxiliary boost controller 118 each drive the boost control signaling. In such a case, the boost control signaling may be combined together and fed to the primary power boost stage 114 .

[0035] In some embodiments, the primary power boost stage 114 may be a DC to DC step-up power converter (or boost power converter) that steps up the voltage (and steps down the current) from its input (supply) to its output (load). Figure 1 In embodiments not illustrated in FIG. 1 , the primary power boost stage 114 may be a type of switch mode power supply (SMPS) comprising at least two semiconductor devices (a diode and a transistor) and at least one energy storage element, a capacitor, an inductor, or a combination of both. In addition, to reduce voltage ripple, filters made of capacitors (sometimes combined with inductors) may be included to the output (load-side filter) and input (supply-side filter) of such a converter. The output V of the primary power boost stage 114 is bulk is fed to the secondary power circuit 120 .

[0036] The secondary power buck stage 124 makes the output V of the primary power boost stage 114 bulk The voltage is reduced (or decreased) to regulate or otherwise maintain the main output 134 to a load (not shown) as constant. Figure 1 In the embodiment shown in FIG. 1 , the step-down (or reduction) is regulated by buck control signaling 127 provided by the secondary controller 126. The secondary controller 126 may be a microcontroller or any digital circuit system that is configured to monitor the primary output 134 of the secondary power buck stage 124 and, in turn, regulate the secondary power buck stage 124 via the buck control signaling 127 during a “normal” (or non-bootloading) mode of operation.

[0037] In some embodiments, the secondary power step-down stage 124 may be a DC to DC power converter (or step-down converter) that reduces voltage (and increases current) from its input (supply) to its output (load). Figure 1 In an embodiment not illustrated in FIG. 1 , the secondary power buck stage 124 may be a type of SMPS comprising at least two semiconductor devices (a diode and a transistor) and at least one energy storage element - a capacitor, an inductor, or a combination of both. However, many modern buck converters replace the diode with a second transistor for synchronous rectification. To reduce voltage ripple, filters made of capacitors (sometimes combined with inductors) may be included to the output (load-side filter) and input (supply-side filter) of such a converter.

[0038] The bias module 122 also receives the output V of the primary power boost stage 114. bulkAnd generate a standby output 132. The power supply device 100 can be used to supply power to a load over a wide range. For example, in a "normal" operating mode, a relatively large amount of power can be provided to the load via the main output 134, but in a "standby" operating mode, a relatively very small amount of power can be provided to the load via the standby output 132. As discussed above, existing switch mode power supplies are unable to support standby output loads in boot loading mode because there is no regulation for the primary power boost stage 114 during the boot loading mode, and the bias module is also unable to work well at low input voltages. Advantageously, the auxiliary boost controller 118 enables the power supply device 100 to continuously drive (or otherwise support) the standby output 132 during the boot loading mode.

[0039] Figure 2 A block diagram illustrating example components of a primary controller 200 in the form of a microcontroller according to some embodiments is depicted. More specifically, Figure 2 The embodiment of FIG. 1 depicts a primary controller 200 including a detailed view of a flash memory map 220 stored in a memory 210 according to some implementations. The primary controller 200 may be Figure 1 The primary controller 116 is shown in FIG. 1 , but alternative configurations are possible. Figure 2 In the illustrated embodiment of FIG. 2 , example components include memory 210, communication interface 230, and processing system 240. Additional or fewer components are possible.

[0040] In some embodiments, the primary controller 200 may be a microcontroller or other circuitry that retrieves and executes software from the memory 210. The primary controller 200 may be implemented in a single device or chip. Figure 1 As discussed, the primary controller 200 is operatively or communicatively coupled with various components including an auxiliary boost controller, a primary power boost stage, and a secondary controller.

[0041] like Figure 2As shown in the embodiment of the present invention, the memory 210 may include a program memory (or code 212) and a data memory (data 214). The primary controller 200 functions discussed herein and other circuit systems and algorithms associated with the primary controller 200 may be implemented as software algorithms and may be stored as software code (e.g., in the code memory 212). Similarly, the values ​​of real-time data and predefined constants may be stored in one or more forms of data memory (e.g., data memory 214). Although not shown, the memory 210 includes flash memory or non-volatile memory (NVM). For example, flash memory may be used to store firmware code for a microcontroller. In such a case, at power-on, the bootloader reads the contents of the flash memory and writes it to the internal SRAM. After the firmware code is written to the SRAM, the primary controller 200 begins to run from the SRAM. Figure 2 In the embodiment of the present invention, the flash memory map 220 illustrates the memory allocation with the boot loading function. More specifically, the flash memory map 220 illustrates various parts of the flash memory, including an unused part 231, a user application part 232, a user application interrupt vector table part 233, another unused part 234, a boot loading part 235, and a boot loading interrupt vector table 236.

[0042] The communication interface 230 may include communication connections and devices that together facilitate communication with other communication devices. The communication interface 230 may be any communication interface through which user application code may be updated, such as, for example, I2C, UART, etc. The processing system 240 may include one or more processor cores configured to retrieve and execute instructions for regulating the primary power boost stage 114 as discussed herein.

[0043] Figure 3 A flow chart illustrating an example process 300 for entering and exiting bootloader mode according to some embodiments is depicted. The example microcontroller process 300 may be implemented by a primary controller (or microprocessor) such as, for example, Figure 1 The primary controller 116, Figure 2 A primary controller, or one or more processors, modules, engines, or components associated therewith - executes.

[0044] Initially, at 310, the primary controller receives a request to enter a bootloader mode. The request to enter the bootloader mode may be initiated by an external system and received by a communication interface, such as, for example, an I2C interface, a UART interface, etc. As discussed herein, the request to enter the bootloader mode includes a request to update user application code. At 320, the primary controller enters the bootloader mode.

[0045] At decision 330, the primary controller determines whether a firmware update is required. If a firmware update is required, at 340, the primary controller asserts the bootload signal. As discussed herein, the assertion of the bootload signal may be driving the bootload signal low. Figure 8 as well as Fig.9A and Fig. 9B However, if a firmware update is not required, at 370 the primary controller jumps to the user application in flash memory, e.g., see Figure 2 The USER_APPLICATION_BASE_ADDRESS in the user application interrupt vector table of the flash memory.

[0046] At 350, the primary controller updates the firmware based on the request. At 360, the primary controller de-asserts the bootload signal. As described above, de-assertion of the bootload signal may drive (or re-drive) the bootload signal high. Finally, at 380, the primary controller exits the bootload mode and resets if necessary. For example, resetting the primary controller may return the primary controller or the power supply device to a "normal" (or non-bootload) operating mode.

[0047] Figure 4 A flow chart illustrating an example process 400 for operating an auxiliary boost controller to assume control of regulation of a primary power boost stage according to some embodiments is depicted. The example process 400 may be performed by an auxiliary boost controller in various embodiments, such as, for example, Figure 1 The auxiliary boost controller 118, or one or more processors, modules, engines, or components associated therewith, may be executed.

[0048] Initially, at 410, the auxiliary boost controller monitors the assertion of a pilot load signal from the primary controller. At decision 420, the auxiliary boost controller determines whether the pilot load signal has been asserted. If the pilot load signal has not been received, the process continues to monitor the assertion of the pilot load signal at 410. If the pilot load signal is received, at 430, the auxiliary boost controller assumes control of regulating the primary power boost stage by, for example, driving a boost regulator signal to regulate the output of the filter to a boost of a minimum threshold voltage.

[0049] At 440, the auxiliary boost controller monitors the bootstrap load signal from the primary controller for deactivation. At decision 450, the auxiliary boost controller determines whether the bootstrap load signal is deactivated. If the bootstrap load signal is deactivated, at 460, the auxiliary boost controller releases control of the bootstrap load signal. As discussed herein, the primary controller may then reassume control of the bootstrap load signal. Although not shown, in some embodiments, the process then returns to monitoring the bootstrap load signal from the primary controller for activation at 410. If the bootstrap load signal is not deactivated at decision 450, the process returns to monitoring the bootstrap load signal for deactivation at 440.

[0050] Figure 5 A state diagram 500 illustrating example operation of an auxiliary boost controller according to some embodiments is depicted. Figure 5 In the embodiment shown in FIG. 5 , state diagram 500 includes states 510, 520, 530, and 540, entry actions 522, 532, and 542, and transition conditions 515, 525, 535, 545, 536, and 546. The example state operations and transitions shown in state diagram 500 may be implemented by an auxiliary boost controller, such as, for example, Figure 1 The auxiliary boost controller 118, or one or more processors, modules, engines, or components associated therewith, may be executed. Additional or fewer states, entry actions, and transition conditions are possible.

[0051] The auxiliary boost controller is initially in the disconnected state 510. As discussed herein, during the disconnected state 510, all components of the power supply device (including the auxiliary boost controller) are disabled. Powering on the power supply device acts as a transition condition 515 that causes the auxiliary boost controller to transition from the disconnected state 510 to the idle state 520. After entering the idle state 520, the auxiliary boost controller performs an entry action 522. Figure 5 In the embodiment shown in FIG. 5 , entering action 522 includes monitoring the validity of the boot load signal. As discussed herein, when the primary controller 116 is performing a boot load operation, the power supply device 100 is referred to as being in a boot load mode. The boot load is a piece of code that allows the user application code to be updated through a communication interface, such as, for example, I2C, UART, etc.

[0052] When operating in the idle state 520, detecting an indication that the bootstrap load signal is asserted serves as a transition condition 525 for causing the auxiliary boost controller to transition from the idle state 520 to the auxiliary protection state 530. As discussed herein, the primary controller asserts the bootstrap load signal to indicate that the primary controller is in the bootstrap load mode. Upon entering the auxiliary protection state 530, the auxiliary boost controller performs entry action 532. Figure 5In the embodiment shown in FIG. 5 , entering action 532 includes assuming control of the primary power boost stage. Although not shown, entering action 532 also includes monitoring for the occurrence of a fault. According to the present invention, the fault condition includes one or more of an overcurrent protection fault or an overvoltage protection fault.

[0053] In the auxiliary protection state 530, the occurrence of a detected fault serves as a transition condition 535 for the auxiliary boost controller to transition from the auxiliary protection state 530 to the fault state 540. After entering the fault state 540, the auxiliary boost controller performs an entry action 542. Figure 5 In the embodiment shown in FIG. 5 , entering action 542 includes performing one or more fault operations. During the fault state 540, detecting the occurrence of a reset acts as a transition condition 546 that causes the auxiliary boost controller to transition from the fault state 540 back to the idle state 520. In addition, the occurrence of a power-off event acts as a transition condition 545 that causes the auxiliary boost controller to transition from any state to the disconnect state 510.

[0054] Figure 6 A signaling diagram 600 illustrating example signaling occurring between various components of a power supply device during a transition from a "normal" (or non-bootloading) operating mode to a bootloading mode and back again, according to some embodiments, is depicted. The primary controller, auxiliary boost controller, and primary power boost stage may be Figure 1 1 , and the primary power boost stage 114, although alternative configurations are possible.

[0055] Initially, the primary controller asserts the drive boost regulator signaling to control regulation of the primary power boost state. When a bootload request is received, the primary controller deactivates the drive boost regulator signaling and asserts the bootload signal. The bootload signal is received by the auxiliary boost control controller, which in turn assumes control of the boost stage until the bootload signal is deactivated. When the bootload signal is deactivated, the auxiliary boost controller releases control of the boost stage by deactivating the drive boost regulator signaling. The primary controller then resumes control of the boost stage by re-asserting the drive boost regulator signaling.

[0056] Figure 7 A flow chart illustrating an example process 700 for continuously supplying power to a standby output of a power supply device in a bootloader mode according to some embodiments is depicted. The example process 700 may be performed by a power supply device, such as, for example, Figure 1 The power supply device 100, or one or more processors, modules, engines or components associated therewith - executes.

[0057] Initially, at 710, the power supply device receives a DC input voltage from a voltage source. At 720, the power supply device filters the DC input for EMI. At 730, the power supply device drives a boost regulator signal to control regulation through a boost stage circuit. At decision 735, the power supply device regulates a boost of the filtered input voltage to a minimum threshold voltage based on the boost regulator signal. At decision 740, the power supply device determines whether the boot load signal is asserted. If not, the process returns to step 710. Otherwise, at 750, the power supply device assumes control of driving the boost regulator signal to continuously supply power to a standby output of the power supply device in a boot load mode. At decision 760, the power supply device determines whether the boot load signal is deactivated. If not, the process returns to step 750. Otherwise, at 770, the power supply device releases control of driving the boost regulator signal.

[0058] Figure 8 An example waveform 800 illustrating intermediate voltage measurements of a power supply device entering a bootloader mode without auxiliary boost control according to some embodiments is depicted. More specifically, as shown in FIG. Figure 8 As shown in the embodiment of FIG. 1 , if the power supply device does not have auxiliary boost control, the bootloader may fail because the primary power boost stage (V bulk ) output and standby output (V AUX ) is not regulated.

[0059] Fig.9A and Fig. 9B Depicted are example waveforms 900A and 900B illustrating intermediate voltage measurements of a power supply device entering and exiting a bootloader mode with auxiliary boost control according to some embodiments. More specifically, the auxiliary boost control may be provided by an auxiliary boost controller, such as, for example, Figure 1 The auxiliary boost controller 118 is provided. Fig.9A and Fig. 9B As shown in the embodiment of FIG. 1 , the standby output (V AUX ).

[0060] As will be appreciated by those skilled in the art, aspects of the present invention may be embodied as systems, methods or computer program products. Therefore, aspects of the present invention may take the form of a complete hardware implementation, a complete software implementation (including firmware, resident software, microcode, etc.) or a combination of software and hardware implementations, which may all be generally referred to herein as "circuits," "modules," or "systems." In addition, aspects of the present invention may take the form of a computer program product embodied in one or more computer-readable media having a computer-readable program code embodied therein.

[0061] The included description and drawings depict specific embodiments to teach those skilled in the art how to make and use the best mode. For the purpose of teaching the principles of the invention, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate the changes from these embodiments that fall within the scope of the present disclosure. Those skilled in the art will also appreciate that the features described above can be combined in various ways to form multiple embodiments. As a result, the present invention is not limited to the specific embodiments described above, but is only limited by the claims and their equivalents.

Claims

1. A power supply device, comprising: an input configured to receive a direct current (DC) input voltage from a voltage source; a filter coupled to the input and configured to reduce electromagnetic interference (EMI) in the input voltage; a boost stage circuit coupled to the filter and configured to regulate a boost voltage of an output of the filter to a minimum threshold voltage based on a boost regulator signal; a primary controller coupled to the boost stage circuit and configured to control the boost regulator signal; a boost assist circuit coupled to the primary controller and configured to assume control of the boost regulator signal during a bootloading mode; a buck stage circuit coupled to the boost stage circuit and configured to regulate a step-down of an output voltage of the boost stage circuit to a predetermined DC output voltage based on a buck regulator signal; a secondary controller coupled to the buck stage circuit and configured to control the buck regulator signal; a bias module coupled to the boost stage circuit and configured to regulate an output voltage of the boost stage circuit to a nominal DC output voltage; a main output configured to supply the predetermined DC output voltage to a load; as well as a standby output configured to supply the nominal DC output voltage to the load, When the primary controller is performing a boot loading operation, the power supply device is said to be in the boot loading mode.

2. The power supply device according to claim 1, wherein the boost stage circuit includes a boost stage, which is configured to: pass the output of the filter when the voltage is greater than the minimum threshold voltage, and increase the output of the filter to the minimum threshold voltage when the output of the filter is less than the minimum threshold voltage.

3. The power supply device according to claim 1, wherein the boost auxiliary circuit is further configured to: maintain an idle state when the power supply device is not in the boot loading mode, and enter the boot loading mode in response to receiving a boot loading signal initiated by the primary controller.

4. The power supply device of claim 1 , wherein the boost assist circuit is configured to assume control of the boost regulator signal during the boot loading mode by driving the boost regulator signal to regulate a boost of the output of the filter to the minimum threshold voltage. 5 . The power supply apparatus of claim 4 , wherein the bias module is further configured to continuously regulate the output voltage of the boost stage circuit to the nominal DC output voltage during the boot loading mode. 6 . The power supply apparatus of claim 3 , wherein the primary controller is further configured to assert the bootload signal in response to receiving a request to enter the bootload mode. 7 . The power supply device according to claim 6 , wherein the primary controller is further configured to perform a firmware update in response to the request, and to invalidate the bootload signal after completing the firmware update. 8 . The power supply apparatus according to claim 1 , wherein the boost auxiliary circuit is further configured to monitor the occurrence of a fault during the boot loading mode.

9. The power supply device according to claim 1, wherein the boost auxiliary circuit comprises a microcontroller or an analog circuit system.

10. The power supply apparatus according to claim 1, wherein the boost stage circuit comprises a switching regulator circuit.

11. A method of continuously supplying power to a standby output of a power supply device in a boot loading mode, the method comprising: receiving a direct current (DC) input voltage from a voltage source through an input port of the power supply device; filtering the input voltage via an electromagnetic interference (EMI) filter; driving a boost regulator signal through a primary controller of the power supply device to control regulation through a boost stage circuit; regulating a boost of the filtered input voltage to a minimum threshold voltage based on the boost regulator signal by the boost stage circuit; asserting, by the primary controller, a bootload signal in response to receiving a request to enter the bootload mode; as well as In response to detecting the validity of the bootload signal, assuming control of driving the boost regulator signal in the bootload mode by a boost assist circuit coupled to the primary controller to continuously supply power to the standby output of the power supply device, When the primary controller is performing a boot loading operation, the power supply device is said to be in the boot loading mode.

12. The method according to claim 11, further comprising: The bootstrap load signal is monitored for validity by the boost assist circuit prior to assuming control of driving the boost regulator signal.

13. The method according to claim 11, further comprising: In response to assuming control of driving the boost regulator signal, the bootload signal is monitored by the boost assist circuit for deassertion.

14. The method according to claim 13, further comprising: In response to detecting the deactivation of the bootload signal, releasing control of driving the boost regulator signal by the boost assist circuit; as well as In response to releasing control of the boost regulator signal, control of driving the boost regulator signal to maintain regulation through the boost stage circuit is resumed by the primary controller of the power supply device.

15. The method of claim 13, wherein the boost stage circuit comprises a switching regulator circuit.

16. The method of claim 13, wherein the boost stage circuit comprises a boost stage configured to pass the output of the filter when the voltage is greater than the minimum threshold voltage, and to increase the output of the filter to the minimum threshold voltage when the output of the filter is less than the minimum threshold voltage.

17. An auxiliary boost control circuit for a low voltage direct current (LVDC) input power supply device, the auxiliary boost control circuit comprising: means for monitoring a bootload signal in an idle state for validity, wherein the bootload signal indicates that a primary controller of the power supply device is entering a bootload mode; as well as means for causing the auxiliary boost control circuit to transition from the idle state to an auxiliary protection state in response to the assertion of the boot load signal, wherein the auxiliary boost control circuit is configured to assume control of a boost regulator signal for controlling regulation of a boost stage circuit to boost an input to a minimum threshold voltage, When the primary controller is performing a boot loading operation, the power supply device is said to be in the boot loading mode.

18. The auxiliary boost control circuit according to claim 17, further comprising: means for monitoring the invalidation of the boot loading signal in the auxiliary protection state; as well as means for transitioning the auxiliary boost control circuit from the auxiliary protection state back to the idle state in response to deassertion of the bootload signal.

19. The auxiliary boost control circuit according to claim 17, further comprising: means for monitoring a fault condition in said auxiliary protection state; as well as Means for transitioning the auxiliary boost control circuit from the auxiliary protection state to a fault state in response to the fault condition.

20. The auxiliary boost control circuit of claim 19, wherein the fault condition comprises one or more of an over-current protection fault or an over-voltage protection fault.

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