Adaptive headroom control to minimize PMIC operating efficiency

A method to maximize efficiency in linear regulators, the method comprising:

• receiving a pre-regulated input voltage from a pre-regulator;
• detecting a plurality of regulator output voltages;
• determining one or more headroom voltages that account for variations of the regulator output voltages at regular operation;
• determining a plurality of minimum required regulator output voltages based on the one or more headroom voltages;
• selectively generating a first headroom voltage related to a variation in one or more operating conditions;
• determining a control voltage that is representative of a maximum of the plurality of minimum required regulator output voltages;
• and
• adjusting the pre-regulated input voltage based on the control voltage.

An adaptive headroom control system, the system comprising:

• a power supply that provides a system input voltage;
• a pre-regulator coupled to receive the system input voltage form the power supply, the pre-regulator converts the system input voltage into a pre-regulated input voltage that is different from the system input voltage;
• voltage regulators coupled to receive the pre-regulated input voltage and convert the pre-regulated input voltage into regulator output voltages;
• one or more loads coupled to the voltage regulators;
• a margin voltage source coupled to a plurality of linear switches to selectively generates a headroom voltage that is related to a variation in one or more operating conditions;
• and
• a control circuit coupled to receive one or more control signals from the voltage regulators, the control circuit generates a select signal corresponding to the one or more control signals and controls the pre-regulator in response to varying headroom voltages requirements of the voltage regulators, thereby, increasing the efficiency of the pre-regulator.