Power management integrated circuit with programmable cold start
AssigneeE-Peas S.A.
InventorsJulien De Vos, Geoffroy Gosset, Cedric Hocquet
Life of this patent
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Abstract
A power management integrated circuit (PMIC) is provided for extracting power from an energy harvester. The PMIC includes a voltage converter to convert an input power at a voltage Vin into an output power at an output voltage Vout_VC. The voltage converter includes, in addition to a main voltage converter circuit, a cold-start circuit for starting the voltage converter from an OFF state. The PMIC further includes an input terminal for receiving a voltage VEN-CS proportional to the converter input voltage Vin and a voltage comparator for comparing the voltage VEN-CS with a reference voltage Vref. A controller enables the cold-start circuit when VEN-CS≥Vref.
Claims17
A power management integrated circuit for managing energy from an energy harvester, said power management integrated circuit comprising:
- a first input terminal that receives an input power from the energy harvester;
- a first output terminal that connects an energy storage device or an application load;
- a voltage converter that converts the input power into an output power, and wherein the voltage converter is operable to provide said output power at an output voltage Vout_VC, said voltage converter comprises:
- a main voltage converter circuit operable when the output voltage Vout_VC is equal or larger than a minimum voltage value Vout_MIN, and
- a cold-start circuit operable when the output voltage Vout_VC is lower than said minimum voltage value Vout_MIN;
- a conducting path that transfers the input power from the first input terminal to the voltage converter;
- a first connecting circuit that transfers the output power of the voltage converter to said first output terminal;
- wherein said power management integrated circuit further comprises:
- a second input terminal that receives a voltage VEN-CS;
- a voltage comparator connected to the second input terminal configured to monitor said voltage VEN-CS at the second input terminal and that compares said voltage VEN-CS with a reference voltage Vref;
- a controller in communication with the voltage converter that controls the voltage converter;
- and
- wherein the controller is configured to enable said cold-start circuit when VEN-CS≥Vref and Vout_VC<Vout_MIN.
A method for energy harvesting from an energy harvester using a voltage converter for converting an input power at a voltage Vin into an output power at an output voltage Vout_VC, and wherein said voltage converter comprises:
- a main voltage converter circuit for operating the voltage converter in a normal operation mode (M2) wherein the output voltage Vout_VC is equal or larger than a minimum voltage value Vout_MIN;
- and
- a cold-start circuit for operating the voltage converter in a degraded mode (M1) wherein the output voltage Vout_VC is lower than said minimum voltage value Vout_MIN;
- said method comprising steps of:
- coupling the energy harvester with the voltage converter for providing said input power;
- providing a voltage comparator for comparing an input voltage with a reference voltage Vref;
- providing a voltage reducer for generating a voltage VEN-CS=Vin/N, wherein Vin is said input voltage and N is reduction factor N=Vopt/Vreg, wherein Vopt is an optimum voltage for extracting a maximum power from said energy harvester;
- comparing said voltage VEN-CS as the input voltage for said voltage comparator with said reference voltage Vref;
- enabling operation of the voltage converter in said degraded mode (M1) with said cold-start circuit when VEN-CS≥Vref and when Vout_VC<Vout_MIN;
- and
- enabling operation of the voltage converter in said normal operation mode (M2) with said main voltage converter circuit when Vout_VC≥Vout_MIN.
Dependencies are inferred from the claim text.