Systems and methods for mitigation of resistor nonlinearity errors in single or multiphase switching voltage regulators employing inductor dcr current sensing

Abstract

Systems and methods for mitigation of resistor nonlinearity errors in a power converter are provided. In at least one embodiment, the power converter comprises at least one power switch coupled to an input voltage, a pulse width modulation (PWM) circuit for generating control pulses for the at least one power switch, at least one output inductor coupled to a respective one of the at least one power switches, a current sensor coupled in parallel with the at least one output inductor, and at least one circuit element. The current sensor comprises at least one capacitor, at least one resistor for each of the at least one output inductors, and is coupled to the PWM circuit at a current bleed node. The at least one circuit element is coupled to the current bleed node and bleeds a bleed current from the current bleed node when a power switch is turned on.

What is claimed is: 
     
         1 . A power converter comprising:
 at least one power switch coupled to an input voltage;   a pulse width modulation circuit for generating control pulses for the at least one power switch;   at least one output inductor, wherein each of the at least one output inductors is coupled to a respective one of the at least one power switches;   a current sensor coupled in parallel with the at least one output inductor for sensing current passing through all of the at least one output inductors,   wherein the current sensor and the pulse width modulation circuit are coupled together at a current bleed node; and   at least one circuit element coupled to the current bleed node, wherein the at least one circuit element bleeds a bleed current from the current bleed node when one or more of the at least one power switches is turned on.   
     
     
         2 . The power converter of  claim 1 , wherein the at least one circuit element is a bleed resistor and wherein when the pulse width modulation circuit generates a turn-on pulse for the at least one power switch the bleed resistor is coupled to ground via a switch. 
     
     
         3 . The power converter of  claim 1 , wherein the at least one circuit element is at least one current controlled current source and wherein the bleed current is a current substantially proportional to the at least one resistor's resistance nonlinearity. 
     
     
         4 . The power converter of  claim 3 , wherein the bleed current is a positive current. 
     
     
         5 . The power converter of  claim 3 , wherein the bleed current is a negative current. 
     
     
         6 . The power converter of  claim 3 , wherein the bleed current is computed using a model resistor's resistance nonlinearity. 
     
     
         7 . The power converter of  claim 3 , wherein the bleed current is dependent on a programmable scaling factor. 
     
     
         8 . The power converter of  claim 1 , wherein the current sensor comprises at least one resistor for each of the at least one output inductors and at least one capacitor. 
     
     
         9 . A controller for a power converter, the controller comprising:
 a current sense input;   a current sense circuit coupled to the current sense input at a current bleed node, wherein the current sense input monitors the current output of the power converter; and   at least one circuit element coupled to the current bleed node, wherein the at least one circuit element bleeds a bleed current from the current bleed node when one or more of the at least one power switches in the power converter is turned on.   
     
     
         10 . The controller of  claim 9 , further comprising:
 a pulse width modulation circuit that generates control signals for at least one power switch that is coupled to an input voltage and is coupled to a respective output inductor, wherein the pulse width modulation circuit is configured to regulate an output voltage of the power converter,   wherein the at least one circuit element is a bleed resistor and wherein when the pulse width modulation circuit generates a turn-on signal for the at least one power switch and the bleed resistor is coupled to ground via a switch.   
     
     
         11 . The controller of  claim 9 , wherein the at least one circuit element is at least one current controlled current source and wherein the bleed current is a current substantially proportional to at least one resistor's resistance nonlinearity. 
     
     
         12 . The controller of  claim 11 , wherein the bleed current is a positive current. 
     
     
         13 . The controller of  claim 11 , wherein the bleed current is a negative current. 
     
     
         14 . The controller of  claim 11 , wherein the bleed current is computed using a model resistor's resistance nonlinearity. 
     
     
         15 . The controller of  claim 11 , wherein the bleed current is dependent on a programmable scaling factor. 
     
     
         16 . An electronic device comprising:
 one or more processing devices;   one or more memory devices communicatively coupled to the one or more processing devices; and   one or more power conversion systems coupled to the one or more processing devices and the one or more memory devices, the one or more power conversion systems including:
 at least one circuit that mitigates resistor non-linearity errors in the one or more power conversion systems, 
 wherein the at least one circuit is coupled to a current bleed node in the one or more power conversion systems and wherein that at least one circuit bleeds a bleed current from the current bleed node when the one or more power conversion systems is turned on. 
   
     
     
         17 . The electronic device of  claim 16 , wherein the at least one circuit is a bleed resistor and wherein when the one or more power conversion systems is turned on the bleed resistor is coupled to ground via a switch. 
     
     
         18 . The electronic device of  claim 16 , wherein the at least one circuit is at least one current controlled current source and wherein the bleed current is a current substantially proportional to at least one resistor's resistance nonlinearity included in the one or more power conversion systems. 
     
     
         19 . The electronic device of  claim 18 , wherein the bleed current is computed using a model resistor's resistance nonlinearity. 
     
     
         20 . The electronic device of  claim 18 , wherein the bleed current is dependent on a programmable scaling factor.