Multi-Phase Power Converter with External Phase Circuits

Abstract

A power management circuit included in a computer system regulates a voltage level of a power supply node used by other circuits in the computer system. The power management circuit includes a control circuit and multiple phase circuits coupled to the regulated power supply node via corresponding inductors. The control circuit selectively activates particular ones of the multiple phase circuits allowing them source respective currents to the regulated power supply node. The control circuit also selectively activates particular ones of other phase circuits that are external to the power management circuit and coupled to the regulated power supply node via their own corresponding inductors. Once activated, the external phase circuits source respective currents to the regulated power supply node via their corresponding inductors.

1 - 20 . (canceled) 
     
     
         21 . An apparatus comprising:
 a first integrated circuit including:
 a primary control circuit configured to generate, using a voltage level of a regulated power supply node, an external demand current and an internal demand current; 
 a first phase circuit coupled to the regulated power supply node via a first inductor, wherein the first phase circuit includes a first driver circuit and is configured to source, based on the internal demand current, a first current to the regulated power supply node via the first inductor; and 
 a second phase circuit including a second driver circuit, wherein the second phase circuit is configured to control operation of the second driver circuit to source, based on the internal demand current, a second current to the regulated power supply node via a second inductor; and 
   a second integrated circuit external to the first integrated circuit, the second integrated circuit including a third driver circuit, wherein the second phase circuit is configured to control operation of the third driver circuit to source third current to the regulated power supply node via the second inductor.   
     
     
         22 . The apparatus of  claim 21 , wherein the primary control circuit is configured to generate a plurality of enable signals, wherein the first phase circuit is further configured to cause the first current to be sourced in response to a determination that a first enable signal of the plurality of enable signals is active, and wherein the second phase circuit is further configured to cause the second current to be sourced, in response to a determination that a second enable signal of the plurality of enable signals is active. 
     
     
         23 . The apparatus of  claim 22 , wherein a number of active enable signals of the plurality of enable signals is based on a value of a load current being drawn from the regulated power supply node. 
     
     
         24 . The apparatus of  claim 22 , wherein the first phase circuit includes a first phase control circuit, and wherein the second phase circuit includes a second phase control circuit. 
     
     
         25 . The apparatus of  claim 24 , wherein the second phase control circuit is configured to enable the second driver circuit in response to receiving a particular enable signal in a first state from the primary control circuit, and further configured to disable the second driver circuit in response to receiving the particular enable signal in a second state. 
     
     
         26 . The apparatus of  claim 24 , wherein the second phase control circuit is configured to provide a control signal to the third driver circuits when the second driver circuit is not enabled. 
     
     
         27 . The apparatus of  claim 21 , wherein the second driver circuit includes:
 a plurality of pull-up devices coupled in parallel between an output node and an input voltage supply node;   a plurality of pull-down devices coupled in parallel between the output node and a ground node; and   a gate control circuit configured to control an amount of current driven onto the output node by controlling a number of the plurality of pull-up devices and a number of the plurality of pull-down devices that are activated during operation.   
     
     
         28 . The apparatus of  claim 21 , wherein the primary control circuit includes:
 a reference generator circuit configured to generate a reference voltage using an input supply voltage, and further configured to provide the reference voltage to the first and second phase circuits; and   clock generator circuit configured to generate a plurality of phase clock signals using an input clock signal, and further configured to provide selected ones of the plurality of phase clock signals to the first and second phase circuits.   
     
     
         29 . A method comprising:
 generating, using a primary control circuit implemented on first integrated circuit and based on a voltage level of a regulated power supply node, an external demand current and an internal demand current;   sourcing, from a first driver circuit of a first phase circuit coupled to the regulated power supply node via a first inductor, a first current to the regulated power supply node via the first inductor, wherein the first phase circuit is implemented on the first integrated circuit;   sourcing, from a second driver circuit of a second phase circuit coupled to the regulated power supply node via a second inductor, a second current to the regulated power supply node via the first inductor, wherein the second phase circuit is implemented on the first integrated circuit;   controlling, using the second phase circuit, a third driver circuit implemented on a second integrated circuit external to the first integrated circuit; and   sourcing, using the third driver circuit, a third current to the regulated supply node via the second inductor.   
     
     
         30 . The method of  claim 29 , further comprising:
 generating, using the primary control circuit, a plurality of enable signals;   sourcing the first current, by the first driver circuit, in response to the first phase circuit determining that a first enable signal of the plurality of enable signals is active;   sourcing the second current, by the second driver circuit, in response to the second phase circuit determining that a second enable signal of the plurality of enable signals is activated;   sourcing the third current, by the third driver circuit, based on a control signal generated by the second phase circuit.   
     
     
         31 . The method of  claim 30 , further comprising the second phase circuit controlling, using the control circuit, and on-time and an off-time of a high side switch of the third driver circuit. 
     
     
         32 . The method of  claim 30 , further comprising the primary control circuit generating a particular number of active enable signals based on a value of a load current being drawn from the regulated power supply node. 
     
     
         33 . The method of  claim 32 , further comprising:
 enabling, using a phase control circuit of the second phase circuit, the second driver circuit in response to receiving a particular one of the plurality of enable signals in a first state; and   disabling, using the phase control circuit of the second phase circuit, the second driver circuit in response to receiving the particular one of the plurality of enable signals in a second state.   
     
     
         34 . The method of  claim 33 , further comprising the phase control circuit of the second phase circuit providing the control signal to the third driver circuit when the second driver circuit is disabled. 
     
     
         35 . The method of  claim 33 , further comprising:
 generating, using a reference generator circuit, a reference voltage using an input supply voltage;   providing the reference voltage to the first and second phase control circuits;   generating, using a clock generator circuit and in input clock signal, a plurality of phase clock signals; and   providing the plurality of phase clock signals to the first and second phase control circuits.   
     
     
         36 . The method of  claim 29 , further comprising, when the second driver circuit is enabled:
 controlling an amount of current driven onto an output node by the second control circuit, wherein the controlling comprises activating, using a gate control circuit, one or more of a plurality of pull-up devices of the second control circuit coupled between an output node and an input voltage supply node, wherein a number of the plurality of pull-up devices activated is dependent.   
     
     
         37 . An apparatus comprising:
 a first inductor;   a second inductor;   a power management circuit, wherein the power management circuit is implemented on a first integrated circuit, and wherein the power management circuit includes:
 a primary control circuit configured to generate, using a voltage level of a regulated power supply node, an external demand current and an internal demand current; 
 a first phase circuit coupled to the regulated power supply node via the first inductor, wherein the first phase circuit includes a first driver circuit and is configured to source, based on the internal demand current, a first current to the regulated power supply node via the first inductor; and 
 a second phase circuit including a second driver circuit, wherein the second phase circuit is configured to control operation of the second driver circuit to source, based on the internal demand current, a second current to the regulated power supply node via a second inductor; and 
   a third driver circuit, wherein the third driver circuit is implemented on a second integrated circuit separate from the first integrated circuit, and wherein the second phase circuit is configured to control operation of the third driver circuit to source third current to the regulated power supply node via the second inductor.   
     
     
         38 . The apparatus of  claim 37 , wherein the primary control circuit is configured to generate a plurality of enable signals, wherein the first phase circuit is further configured to cause the first current to be sourced in response to a determination that a first enable signal of the plurality of enable signals is active, and wherein the second phase circuit is further configured to cause the second current to be sourced, in response to a determination that a second enable signal of the plurality of enable signals is active. 
     
     
         39 . The apparatus of  claim 38 , wherein the first phase circuit includes a first phase control circuit, and wherein the second phase circuit includes a second phase control circuit, wherein the second phase control circuit is configured to enable the second driver circuit in response to receiving a particular enable signal in a first state from the primary control circuit, and further configured to disable the second driver circuit in response to receiving the particular enable signal in a second state, and wherein the second phase control circuit is configured to provide a control signal to the third driver circuits when the second driver circuit is not enabled. 
     
     
         40 . The apparatus of  claim 37 , wherein a given one of the first and second driver circuits includes:
 a plurality of pull-up devices coupled in parallel between an output node and an input voltage supply node;   a plurality of pull-down devices coupled in parallel between the output node and a ground node; and   a gate control circuit configured to control an amount of current driven onto the output node by controlling a number of the plurality of pull-up devices and a number of the plurality of pull-down devices that are activated during operation.