Abstract:
In accordance with aspects of the present invention, and power and timing supply is presented. The supply includes a power supply providing a supply voltage as a function of a load current; and a timing generator providing a frequency signal as a function of the supply voltage, wherein the supply voltage and the frequency signal are within a safe operating range.

Description:
RELATED APPLICATIONS 
       [0001]    The present disclosure claims priority to U.S. Provisional Patent Application 62/347,515, entitled “Autonomous Power and Timing System,” filed on Jun. 8, 2016, which is herein incorporated by reference in its entirety. 
     
    
     BACKGROUND 
     Technical Field 
       [0002]    Embodiments of the present invention are related power supplies and, in particular, to an autonomous power and timing system to provide power to a load. 
       Discussion of Related Art 
       [0003]    Power management is an integral component of overall system design. Power management has become an important aspect of circuit design. In particular, providing power at reliable levels under conditions of widely varying loads and frequency requirements is a challenge. 
         [0004]    Consequently, there is a need for better power supplies. 
       SUMMARY 
       [0005]    In accordance with aspects of the present invention, and power and timing supply is presented. The supply includes a power supply providing a supply voltage as a function of a load current; and a timing generator providing a frequency signal as a function of the supply voltage, wherein the supply voltage and the frequency signal are within a safe operating range. 
         [0006]    These and other embodiments are further discussed below with respect to the following figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  illustrates a power and timing system according to aspects of the present invention. 
           [0008]      FIG. 2  illustrates an example function between voltage and current for the power generator illustrated in  FIG. 1 . 
           [0009]      FIG. 3  illustrates a relationship between frequency and voltage of the timing generator illustrated in  FIG. 1 . 
           [0010]      FIG. 4  illustrates an example relationship between frequency and voltage of the timing generator illustrated in  FIG. 1 . 
           [0011]      FIG. 5  illustrates an example relationship between frequency and voltage of the timing generator illustrated in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    In the following description, specific details are set forth describing some embodiments of the present invention. It will be apparent, however, to one skilled in the art that some embodiments may be practiced without some or all of these specific details. The specific embodiments disclosed herein are meant to be illustrative but not limiting. One skilled in the art may realize other elements that, although not specifically described here, are within the scope and the spirit of this disclosure. 
         [0013]    This description and the accompanying drawings that illustrate inventive aspects and embodiments should not be taken as limiting—the claims define the protected invention. Various changes may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known structures and techniques have not been shown or described in detail in order not to obscure the invention. 
         [0014]    Elements and their associated aspects that are described in detail with reference to one embodiment may, whenever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment. 
         [0015]      FIG. 1  illustrates a power system  100  according to some embodiments of the present invention. As illustrated in  FIG. 1 , power system  100  includes a power supply  102  that outputs a voltage Vsup to load  106 . As illustrated in  FIG. 1 , the voltage output of power supply is given by V=f(I), where I is the current provided to load  106 . The supply voltage is input to a load  106  and at least a derivative of the voltage Vsup is provided to a programmable timing generator  104 . Generator  104  produces a frequency f that is, at least in part, a function of the voltage received into programmable timing generator  104 , f=g(V). The frequency f is also input to load  106 , which uses the frequency f to modulate the input voltage Vsup. 
         [0016]    Consequently, power supply  102  is capable of measuring or receiving the load current I. Timing generator  104  receives the load supply voltage Vsup or a voltage proportional to the load supply voltage Vsup, which is dependent on the current drawn by the load  106 . 
         [0017]    Power supply  102  may include a microprocessor and memory to hold programming instructions and data to perform the calculation of the output voltage Vsup based on the load current I. In some embodiments, the calculation of the output voltage can be performed by dedicated circuitry within power supply  102 . 
         [0018]    The relationship between supply voltage Vsup and supply current I can be a linear or nonlinear relationship. In some embodiments, power supply  102  may include a lookup table or another function description that defines the function f(I), the current/voltage relation. The function f(I) may include hysteresis. 
         [0019]      FIG. 2  illustrates an example current/voltage relationship f(I) that includes hysteresis. The voltage range for load  106  can be programmed to match the acceptable supply voltage range for load  106 . As is illustrated in  FIG. 2 , the function f(I) can be a step function with hysteresis so that operation with increasing current is different from operation with decreasing current. Such a function can be calculated using a look-up table, for example. 
         [0020]    As is further illustrated in  FIG. 1 , the output voltage Vsup from power supply  102  is fed directly as a supply voltage or as an independent input voltage to timing generator  104 . The supply voltage can then be used to determine the output frequency of timing generator  104 . The determination of frequency f as a function of voltage can also be based on a lookup table or based on a function for the load  102 . As such, timing generator  104  may also include a processor and memory for holding programming and data that can calculate the function g(V). In some embodiments, timing generator  104  and power supply  102  may share a single microprocessor system that is shared. The single microprocessor can calculate both the voltage and the frequency. 
         [0021]      FIG. 3  illustrates the frequency as a function of voltage relationship that may be executed for timing generator  104 . The frequency range can be programmed in timing generator  104  to match an acceptable frequency range for load  106 . 
         [0022]    As is further illustrated in  FIG. 3 , the supply voltage and the frequency can be programmed to stay within a safe operating area (SOA). As illustrated in  FIG. 3 , the output voltage ranges from a Vmin to a Vmax. The frequency range can be from a minimum frequency fmin to a maximum frequency fmax, where the maximum frequency fmax depends on the voltage. For example, there is a maximum frequency fmax at the minimum voltage Vmin and a different maximum frequency fmax at the maximum voltage Vmax.  FIG. 4  shows a relationship where the frequency of load  106  can go to zero (0). In some systems, e.g. where DRAM is used, the frequency cannot go below a certain limit and therefore the minimum frequency (fmin@Vmin) is greater than 0. 
         [0023]    As discussed above,  FIG. 1  shows a block diagram of a proposed power/timing system  100 . Power supply  102  generates a supply voltage Vsup to load  106 . This Vsup, or a derivative of Vsup, is also input to timing generator  104 . Vsup is modulated by the load current, which means that with a changing load current the output voltage Vsup is changed proportionally or in certain steps for a load current range as is illustrated in  FIG. 2 . 
         [0024]    Vsup can either by the supply voltage of the timing generator or an independent input voltage. Vsup is then decoded in the timing generator to generate a Vsup specific frequency for a given Vsup or a range of Vsup, as is illustrated in  FIG. 3 . Vsup and the frequency are programmed to stay with the safe operating area SOA, as is illustrated in  FIG. 3 ,  FIG. 4 , and  FIG. 5 . In certain cases, e.g. when there is an embedded DRAM included in the load, the frequency f is programmed not to go lower than a predefined value as is illustrated in  FIG. 3  and  FIG. 5 .  FIG. 4  illustrates an example where the minimum frequency can be 0. 
         [0025]    The above detailed description is provided to illustrate specific embodiments of the present invention and is not intended to be limiting. Numerous variations and modifications within the scope of the present invention are possible. The present invention is set forth in the following claims.