Power management efficiency using DC-DC and linear regulators in conjunction

A electronic device comprising:

• a battery operable to supply an input voltage;
• a power management unit comprising:
• a first stage power regulator operable to adjust said input voltage based on a feedback signal, wherein said first stage power regulator generates an adjusted input voltage for a second stage power regulator such that said second stage power regulator operates with reduced power dissipation;
• said second stage power regulator comprising a plurality of low dropout regulators coupled to said first stage power regulator, wherein each of said plurality of low dropout regulators adjusts said adjusted input voltage to output a desired output voltage, wherein each desired output voltage controls power to a respective section of said electronic device;
• and
• a control circuitry, coupled to said first stage and said second stage, for generating said feedback signal based on dropout voltages of said plurality of low dropout voltages and said desired output voltage for said plurality of low dropout regulators;
• and
• a processor operable to process data.

A method of managing power in a electronic device, said method comprising:

• accessing an input voltage;
• in a first stage power regulator, adjusting said received input voltage based on a feedback signal, wherein said first stage power regulator generates an adjusted input voltage for a second stage power regulator such that said second stage power regulator operates with reduced power dissipation;
• in said second stage power regulator comprising a plurality of low dropout regulators, each of said plurality of low dropout regulators adjusting said adjusted input voltage to output a desired output voltage, wherein each of said desired output voltage controls power to a respective section of said electronic device;
• and
• in a control circuitry, generating said feedback signal based on dropout voltages of said plurality of low dropout voltages and said desired output voltage for said plurality of low dropout regulators.