Apparatus and method for power management with a two-loop architecture

Abstract

Described are apparatuses and methods for power management. The apparatus may include a power gate including a plurality of current sources. The power gate may be coupled to a load. The apparatus may further include a voltage control circuit, coupled to the power gate, to determine and select one or more current sources of the plurality of current sources to supply to the load. The apparatus may further include a current control circuit, coupled to the voltage control circuit, to control individual current sources of the one or more current sources to output a constant current. Other embodiments may be described and/or claimed.

1 - 20 . (canceled) 
     
     
         21 . A circuit, comprising:
 a power gate coupled to a load, the power gate including a plurality of current sources;   a first control loop to select one or more current sources of the plurality of current sources to supply to the load; and   a second control loop to control respective currents provided by the individual current sources to regulate an output current provided by the power gate to the load.   
     
     
         22 . The circuit of  claim 21 , wherein the second control loop is to control the respective currents provided by the individual current sources to regulate the output current to have a constant value. 
     
     
         23 . The circuit of  claim 21 , wherein the plurality of current sources are coupled to a power source, and wherein the second control loop includes a replica circuit to output an output voltage to the power gate to regulate the output current. 
     
     
         24 . The circuit of  claim 21 , wherein the second control loop comprises a replica circuit to output a bias voltage to the power gate and to regulate the bias voltage to a desired value of an output voltage of the power gate based at least in part on a voltage identity received by the second control loop. 
     
     
         25 . The circuit of  claim 24 , wherein the replica circuit comprises an amplifier to receive the voltage identity and to output the bias voltage. 
     
     
         26 . The circuit of  claim 25 , wherein the amplifier is a first amplifier, and wherein the replica circuit further comprises a second amplifier coupled to the first amplifier to receive the bias voltage and to buffer the bias voltage. 
     
     
         27 . The circuit of  claim 24 , wherein the plurality of current sources comprise respective transistors, wherein the replica circuit is to provide the bias voltage to gate terminals of the transistors that correspond to the selected current sources. 
     
     
         28 . The circuit of  claim 21 , wherein the first control loop comprises an analog circuit to generate a digital code that corresponds to an error signal based on a feedback voltage received from the power gate and a reference voltage. 
     
     
         29 . The circuit of  claim 28 , wherein the first control loop further comprises a digital controller, coupled to the analog circuit, to select the one or more current sources based at least in part on the digital code. 
     
     
         30 . The circuit of  claim 21 , wherein a gain of the first control loop is independent of an output impedance of the power gate. 
     
     
         31 . The circuit of  claim 21 , wherein a gain of the second control loop is independent of a number of the one or more current sources selected by the first control loop. 
     
     
         32 . The circuit of  claim 21 , wherein a cycle of the first control loop is faster than a cycle of the second control loop. 
     
     
         33 . The circuit of  claim 21 , wherein the second control loop is to modulate a resistance of the power gate as a function of a dropout between a supply voltage and an output voltage of the power gate. 
     
     
         34 . A circuit, comprising:
 means for determining a number of current sources of a power gate to activate to provide an output current to a load;   means for activating the determined number of current sources; and   means for regulating respective currents provided by the activated current sources to provide the output current.   
     
     
         35 . The circuit of  claim 34 , wherein the means for regulating the respective currents is to regulate the respective currents to provide the output current with a constant value. 
     
     
         36 . The circuit of  claim 34 , wherein the means for regulating the respective currents comprises:
 means for modulating a bias voltage to a desired output voltage of the power gate; and   means for supplying the bias voltage to transistors of the respective current sources in the power gate to regulate the respective currents.   
     
     
         37 . The circuit of  claim 36 , wherein the means for regulating the respective currents further comprises means for discharging a gate-to-source capacitor and a gate-to-drain capacitor of the transistors based on the bias voltage. 
     
     
         38 . The circuit of  claim 34 , further comprising:
 means for modulating a resistance of the power gate as a function of a dropout between a supply voltage and an output voltage of the power gate.   
     
     
         39 . A computer system comprising:
 a non-volatile memory;   a display; and   an integrated circuit (IC) die coupled to the non-volatile memory and the display, the IC die including:
 a power island with a power gate coupled to a load, the power gate including a plurality of current sources; 
 a voltage control circuit coupled to the power gate, the voltage control circuit to select one or more current sources of the plurality of current sources to supply an output current to the load; and 
 a current control circuit coupled to the voltage control circuit, the current control circuit to control individual current sources of the one or more current sources to regulate the output current. 
   
     
     
         40 . The system of  claim 39 , wherein the voltage control circuit includes a control loop with a gain that is independent of a number of the one or more current sources selected by the voltage control circuit. 
     
     
         41 . The system of  claim 39 , wherein the current control circuit is to modulate a resistance of the power gate as a function of a dropout between a supply voltage and an output voltage of the power gate. 
     
     
         42 . The system of  claim 39 , wherein the current control circuit comprises a replica circuit to output a bias voltage and to regulate the bias voltage to a desired value of an output voltage of the power gate based at least in part on a voltage identity received by the second control loop, wherein the current control circuit is to provide the bias voltage to respective transistors of the selected current sources to regulate the output current.