Abstract:
In general, in one aspect, the disclosure describes a system comprising a power converter, a power delivery network, a load, and a communication link between the power converter and the load. The communication link is to implement a training sequence to dynamically adjust parameters of the power converter and set load-line slope based on implementation of the system. The load includes a training capability to generate stimuli having defined patterns and to update on the stimuli application to the power converter over the communication link. The power converter includes a controller to measure noise amplitude in a power output based on the stimuli, to adjust loop parameters to reduce the noise amplitude, and to set the load-line for the power converter based on the adjusting.

Description:
BACKGROUND 
       [0001]    Power converters are utilized to convert power from one domain to another and provide the converted power to a load. The behavior of the power converter may be affected by multiple factors within the system with which it serves. Design constraints include input and output voltage levels, load range and dynamics and output voltage performance targets. The main sources of design variation in this context are passive components such as inductors and capacitors values, precision, reliability and finally the actual number of attached passive parts and their locations, based on the board area and bill of material optimization. The use of a power converter with a particular load within a system may require the converter compensation parameters to be modified (possibly by modifying the delivery network) or to tolerate the performance of the power converter in the system design. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]    The features and advantages of the various embodiments will become apparent from the following detailed description in which: 
           [0003]      FIG. 1  illustrates a high level block diagram of a power supply system; 
           [0004]      FIG. 2  illustrates a block diagram of a power supply system providing dynamic power conversion tuning, according to one embodiment; 
           [0005]      FIG. 3  illustrates a timing diagram of an example implementation of a controller training capability (CTC) procedure, according to one embodiment; and 
           [0006]      FIG. 4  illustrates example improvement in impedance profile of the output voltage of the power converter over the frequency domain, according to one embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]      FIG. 1  illustrates a high level block diagram of a power supply system  100 . The system  100  includes a power convertor  110 , a delivery network  120  and a load (processor)  130 . The power converter  110  converts a first power domain (e.g., platform power) to a second power domain required by the load  130  and regulates the second power domain. The delivery network  120  delivers the second power domain to the load  130 . The load  130  performs processing for the platform  100 . The interaction between the power converter  110 , the delivery network  120  and the load  130  may affect the efficiency and performance of both the power converter  110  and the load  130 . The efficiency and performance of the power converter  110  may affect the performance, reliability and consumed power of the system  100 . 
         [0008]      FIG. 2  illustrates a block diagram of a power supply system  200  providing dynamic power conversion tuning. The system  200  includes a power convertor  210 , a delivery network  220 , a load (processor)  230 , and a bidirectional interface  240 . The bidirectional interface  240  provides a communication link between the between the load  230  and the power converter  210 . The power converter  210  may include a controller  250 , power circuitry (e.g., high side transistors  255 , low side transistors  260 , inductors  265 ) and a communications interface (not illustrated) to connect to the communication link  240 . The controller  250  includes a controller training capability (CTC)  270 . The power delivery network  220  may include decoupling paths  275  that may include capacitors  280 , parasitic resistive paths  285  and parasitic inductive paths  290 . The load  230  may include functional circuitry (not illustrated), a CTC  295  and a communications interface (not illustrated) to connect to the communication link  240 . The load CTC  295  and the controller CTC  270  may communicate there between in order to dynamically adjust the power convertor  210  parameters to improve performance and efficiency based on the environment the power converter  210  is being used in and the state and dynamic requirements of the load  230 . An interface protocol may be defined to enable the communications between the load CTC  295  and the controller CTC  270 . 
         [0009]    The load CTC  295  may produce stimuli at a defined pattern and provide the stimuli to the controller  250  (via the communications link  240 ). The stimuli at the defined pattern may represent load application and defined dynamic changes thereto (e.g., load toggling). The stimuli may be applied at a defined frequency. The stimuli may create noise in the power (voltage) output from the power converter  210  at the defined frequency. The voltage noise amplitude is then measured and reported thought the communication link  240 , and the controller  250  loop parameters are adjusted in order to reduce the noise (e.g., reduce the magnitude of the voltage oscillations). The controller  250  may provide the noise measurements to the load  230  since most of the infrastructure for voltage sampling and processing is already contained therein. After the controller  250  has adjusted its loop parameters and thus the converter  210  behavior, the controller  250  may inform the load  230  and the load CTC  295  may again provide the stimuli to the controller  250 . The mutual interaction between the load CTC  295  and the controller  250  may continue in order to optimize the voltage noise amplitude. After it determined that the adjustments are satisfactory (e.g., the noise generated is tolerable, the noise is as low as possible under the specific conditions), the adjustment (converter loop parameters) may be recorded in the controller CTC  270 . 
         [0010]    The load CTC  295  may then produce different stimuli at a next defined pattern and provide the stimuli to the controller  250 . The controller  250  and the load CTC  295  may mutually interact in order to optimize the voltage noise amplitude and to provide the controller  250  with the required loop parameters. 
         [0011]    The specific set of patterns that the stimuli are generated for may be configured (e.g., by firmware). Periodic patterns at given frequency points may be selected to represent the location of susceptibility to power delivery resonances or converter  210  related mismatches. For example, a frequency in the range of 1-10 KHz may be selected for tuning device mismatches (e.g., DCR sense filter mismatch) and a frequency of between 100-400 KHz may be selected for resonances (e.g., output capacitors deprivation) of the power delivery network  220 . 
         [0012]    The CTC procedure described above may be initiated by the load  230  at specific instances (e.g., initial use, reset, crash). The load  230  may halt its operation in order to initiate the CTC procedure. For example, upon initial use of the load  230  once the power ramp of the load  230  is complete and voltage level is set the CTC initiation may occur. As part of the CTC procedure, the load-line (e.g., voltage positioning slope) of the power converter  210  can be set based on the dynamic optimization and adjustments that were made and are stored in the controller CTC  270  (the training of the converter  210  for the specific platform). 
         [0013]      FIG. 3  illustrates a timing diagram of an example implementation of a CTC procedure. The power is ramped up and after the associated voltage level of the power converter  210  is achieved (voltage identification (VID) settle point) the CTC procedure is implemented. At this point, the load functions may still be disabled or if they have been activated, they may be halted during implementation of the CTC procedure. The load CTC  295  may initiate a first iteration (e.g., iteration 0) of the stimuli at a first pattern (e.g., 150 KHz repetitive load toggling) which may result in noise (oscillations on output voltage)  300 . The controller  250  of the power converter  210  may perform compensation parameter adjustments to reduce the noise. After the controller  250  has made some adjustments, the load CTC  295  may initiate another iteration (e.g., iteration 1) of the first pattern stimuli which may result in noise  310  having a lower amplitude of oscillations then the noise  300  created by the iteration 0. 
         [0014]    If the noise is determined to be at an acceptable level for the first stimuli, the load CTC  295  may initiate a first iteration (e.g., iteration 0) of a repetitive stimuli at a second (different from the first) stimuli pattern (e.g., 3 KHz repetitive load toggling) which may result in noise  320 . The controller  250  may perform compensation parameter adjustments. The load CTC  295  may then initiate another iteration (e.g., iteration 1) at the second stimuli pattern, which may result in less, noise  330 . After the CTC procedure is complete, the voltage positioning slope (DC load line) may be set and the operation of the load  230  can be allowed or returned (e.g., power good is asserted). 
         [0015]    The DC load-line may be set based on the parameters learned about the specific platform and the resulting dynamic noise magnitudes that were achieved through the converter training. For example, the converter  210  may have learned the minimal achieved dynamic AC droops that can be affected by the power converter compensation bandwidth (e.g., 3rd droops, possibly 2nd droops). The DC load-line no longer needs to be bound to the worst-case design scenario that can be expected from the load. An improved DC load-line can be used to save energy by lowering the VID without effecting load performance or to increase load performance by raising the VID without affecting reliability. These improvements are based on the reduced voltage noise window achieved by the CTC procedure. 
         [0016]    It should be noted that the timing diagram of  FIG. 3  included two iterations for each unique load pattern but it is not limited thereto. Rather, the number of iterations may be based on how many iterations are required to achieve an acceptable noise level or a time budget for the CTC procedure that might serve as upper limit to the flow duration. The acceptable noise level may be determined by the load  230 . The acceptable noise level may be configurable. The amount of time that compensator parameter adjustments may be made by the controller  250  before the load CTC  295  resends a stimuli may commonly be bound to avoid indefinite time for the flow. For example, the adjustments may be made for a defined period (fixed or configurable) or based on a determination that the adjustments are complete. The determination of when the adjustments are complete may be made by the power converter  210  or by the load  230 . In cases where the flow is being finished because the defined period lapsed (e.g., met or exceeded duration time limit) or the optimization process does not converge, the default initial settings or the best intermediate results may be used. The number of patterns, their spectral content, and waveform shapes provided from the load CTC  295  to the converter  210  are not limited to those illustrated. The number of patterns, their spectral content, and the waveform shapes may be configured by a user (e.g., platform designer). 
         [0017]      FIG. 4  illustrates example improvement in impedance profile of the power converter  210  output voltage over the frequency domain. An example impedance profile before application of the CTC  400  shows resonance peaks in the impedance profile at the certain frequencies (e.g., 3 KHz, 150 KHz). An example post CTC impedance profile  410  shows that the resonance peaks have been leveled out and that the impedance profile has a relatively flat slope at the frequency range of the converter bandwidth. That is, inside the range of converter bandwidth specific resonances can be optimized by the compensator CTC adjustment iterative process. The frequency regions above the converter bandwidth and surely those above the converter effective switching frequency are not relevant and cannot be affected by the CTC or any of the converter related features. 
         [0018]    At the end of the procedure, the DC load-line slope can be set to achieve adjustable voltage positioning (AVP) matching with the converter output filter stage. As illustrated, the DC load line was able to be reduced based on the CTC. It should be noted that the CTC may have a maximum limit for the DC load-line. 
         [0019]    Dynamic adjustment of the converter compensation enables reduction of power supply noise, and may enable individualized settling of load-line slope per given implementation. This may enable reduction of VID and increase in efficiency, energy saving, and reliability related degradations. 
         [0020]    It should be noted that the disclosure focused on the load  230  providing the stimuli and synchronizing the flow for the CTC process, but is not limited thereto. While a processor load can easily be designed to define the agent creating the stimuli and the interface protocol providing the communications, regular loads may find those requirements too complex to handle. According to one embodiment, the controller  250  may send stimuli signals to an external device (dummy load) that may generate a mimic of load transient changes in given frequency point and specified magnitudes. The controller response could be also optimized for reference voltage transients, generated by the controller during the training period. 
         [0021]    Although the disclosure has been illustrated by reference to specific embodiments, it will be apparent that the disclosure is not limited thereto as various changes and modifications may be made thereto without departing from the scope. Reference to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described therein is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” appearing in various places throughout the specification are not necessarily all referring to the same embodiment. 
         [0022]    The various embodiments are intended to be protected broadly within the spirit and scope of the appended claims.