Granted Patent B2

US 8,339,105 · App. 12/682,452 · Granted Dec 25, 2012

Abstract

Claims (26)

1. A power management arrangement for a mobile device comprising a digital circuit block and an analog circuit block, the power management arrangement being arranged to supply a first voltage to the analog circuit block and a second voltage to the digital circuit block, the power management arrangement comprising:

an input unit adapted to receive input voltages from a plurality of power sources;

a first voltage regulator coupled to the input unit and for supplying the first voltage;

a second voltage regulator for supplying the second voltage and arranged to be selectively coupled to one of the first voltage regulator and input unit; and

control logic adapted to select which of the received input voltages from the plurality of power sources provides power to the first and second voltage regulators, and to determine the magnitude of the first and second voltages supplied by the first and second voltage regulators.

2. A power management arrangement as claimed in claim 1 , wherein the control logic is adapted to select to which of the input unit and first voltage regulator the second voltage regulator is coupled based on an operating state of the mobile device.

3. A power management arrangement as claimed in claim 1 , wherein the control logic is adapted to select which of the received input voltages from the plurality of power sources provides power to the first and second voltage regulators based on the operating state of the device and a level of each of the received input voltages from the plurality of power sources.

4. A power management arrangement as claimed in claim 1 , wherein the control logic is adapted to set the magnitude of the first and second voltages provided by the first and second voltage regulators according to at least one of: an operating state of the device, and a level of each of the received input voltages from the plurality of power sources.

5. A power management arrangement as claimed in claim 1 , wherein the control block comprises a comparator for comparing the levels of the received input voltages in order to determine the received input voltage having the highest level.

6. A power management arrangement as claimed in claim 1 , wherein the first and second voltage regulators and control logic are arranged such that the control logic can deactivate the first voltage regulator.

7. A power management arrangement as claimed in claim 6 , comprising:

a first switch coupled in parallel with the first voltage regulator and between the second voltage regulator and the input unit; and

a second switch coupled between the second voltage regulator and the first voltage regulator, the first and second switches controlled by control logic such that closing one switch and opening of the other switch deactivates the first voltage regulator.

8. A power management arrangement as claimed in claim 7 , wherein the first and second switches operate such that when one switch is closed the other switch is open.

9. A power management arrangement as claimed in claim 1 , wherein the first voltage is not less than the second voltage.

10. A power management arrangement as claimed in claim 4 , wherein the control logic is arranged to instruct the input unit to draw power from the received input voltage having the highest level when the mobile device is substantially inactive.

11. A power management arrangement as claimed in claim 10 , wherein when the highest available voltage is provided by a power source internal to the device, the first voltage regulator is disabled by operating a switch.

12. A power management arrangement as claimed in claim 4 , wherein the control logic is arranged to instruct the input unit to take power from a predetermined one of the received input voltages when the mobile device is activated.

13. A power management arrangement as claimed in claim 12 , wherein the predetermined one of the received input voltages is provided by a battery.

14. A power management arrangement as claimed in claim 1 , wherein the power management arrangement is provided on a single integrated circuit.

15. A power management arrangement as claimed in claim 1 , further comprising a bandgap voltage reference between an output of the second voltage regulator and a ground voltage.

16. A power management arrangement as claimed in claim 15 , wherein the bandgap voltage reference is merged with the second voltage regulator.

17. An electronic device connectable to a plurality of power sources, said electronic device including a power management arrangement of claim 1 .

18. An electronic device as claimed in claim 17 , wherein the power sources include a main battery and a secondary battery.

19. A power management arrangement as claimed in claim 2 wherein the control logic is adapted to select which of the received input voltages from the plurality of power sources provides power to the first and second voltage regulators based on the operating state of the device and a level of each of the received input voltages from the plurality of power sources.

20. A power management arrangement as claimed in claim 2 , wherein the control logic is adapted to set the magnitude of the first and second voltages provided by the first and second voltage regulators according to at least one of: an operating state of the device, and a level of each of the received input voltages from the plurality of power sources.

Assignments (27)