Multiphase inductive boost converter with multiple operational phases

1. A battery management circuit for a battery-powered mobile device, comprising:

a multi-phase inductive boost converter having at least two boost converter phases wherein each of the at least two boost converter phases comprises its own respective inductor, its own respective charge switch, and its own respective rectification switch; and

voltage monitoring and control circuitry configured to:

compare a battery voltage of a battery of the battery-powered mobile device to a minimum threshold voltage;

enable the boost converter to provide a boosted output voltage at an output of the boost converter from a source voltage of the battery if the battery voltage is below the minimum threshold voltage; and

bypass the battery voltage to the output of the boost converter via one or more of the charge switches and rectification switches of the at least two boost converter phases if the battery voltage is above the minimum threshold voltage.

2. The battery management circuit of claim 1 , further comprising measurement circuitry configured to monitor current flow through the battery management circuit.

3. The battery management circuit of claim 2 , wherein the minimum threshold voltage is a function of a monitored current level.

4. The battery management circuit of claim 3 , further comprising:

a low-resistance path;

a high-resistance path having electrical resistance significantly higher than the low-resistance path; and

the measurement circuitry configured to:

measure the monitored current level through the low-resistance path in a first range of electrical current; and

measure the monitored current level through the high-resistance path in a second range of electrical current lower in magnitude than the first range.

5. The battery management circuit of claim 4 , wherein the low-resistance path comprises a path through a sense resistor coupled between the battery and a bypass switch.

6. The battery management circuit of claim 5 , wherein the high-resistance path comprises a path through a sense resistor and at least one switch of the boost converter.

7. A method, in a battery management circuit for a battery-powered mobile device wherein the battery management circuit comprises voltage monitoring circuitry and a multi-phase inductive boost converter having at least two boost converter phases wherein each of the at least two boost converter phases comprises its own respective inductor, its own respective charge switch, and its own respective rectification switch, the method comprising:

comparing a battery voltage of a battery of the battery-powered mobile device to a minimum threshold voltage;

enabling the boost converter to provide a boosted output voltage at an output of the boost converter from a source voltage of the battery if the battery voltage is below the minimum threshold voltage; and

bypassing the battery voltage to the output of the boost converter if the battery voltage is above the minimum threshold voltage.

8. The method of claim 7 , further comprising monitoring current flow through the battery management circuit with measurement circuitry.

9. The method of claim 8 , wherein the minimum threshold voltage is a function of a monitored current level.

10. The method of claim 9 , further comprising:

measuring the monitored current level through a low-resistance path of the battery management system in a first range of electrical current; and

measuring the monitored current level through a high-resistance path having electrical resistance significantly higher than the low-resistance path in a second range of electrical current lower in magnitude than the first range.

11. The method of claim 10 , wherein the low-resistance path comprises a path through a sense resistor coupled between the battery and a bypass switch.

12. The method of claim 11 , wherein the high-resistance path comprises a path through a sense resistor and at least one switch of the boost converter.

13. A battery management system configured to electrically couple to a battery, the battery management system comprising:

a boost converter comprising a plurality of switches arranged to selectively provide a boosted output voltage at an output of the boost converter from a source voltage of the battery, the boost converter comprising a plurality of boost converter phases comprising:

a first boost converter phase comprising a first inductor, a first charge switch, and a first rectification switch; and

a second boost converter phase comprising a second inductor, a second charge switch, and a second rectification switch; and

wherein:

the battery management system is operable in a plurality of modes comprising a bypass mode wherein the source voltage is bypassed to the output; and

when the battery management system is in the bypass mode, the first rectification switch and the second rectification switch are activated and the first charge switch and the second charge switch are deactivated.

14. The battery management system of claim 13 , wherein the battery management system operates in the bypass mode when a battery voltage of the battery is above a minimum threshold voltage.

15. The battery management system of claim 13 , wherein:

the plurality of boost converter phases comprises a third boost converter phase comprising a third inductor, a third charge switch, and a third rectification switch; and

when the battery management system is in the bypass mode, the third rectification switch is activated and the third charge switch is deactivated.

16. A method, in a battery management system configured to electrically couple to a battery, the battery management system comprising a boost converter comprising a plurality of switches arranged to selectively provide a boosted output voltage at an output of the boost converter from a source voltage of the battery, wherein the boost converter comprises a plurality of boost converter phases comprising a first boost converter phase comprising a first inductor, a first charge switch, and a first rectification switch and a second boost converter phase comprising a second inductor, a second charge switch, and a second rectification switch, the method comprising:

operating the battery management system in a plurality of modes comprising a bypass mode wherein the source voltage is bypassed to the output; and

when the battery management system is in the bypass mode, activating the first rectification switch and the second rectification switch and deactivating the first charge switch and the second charge switch.

17. The method of claim 16 , further comprising operating the battery management system in the bypass mode when a battery voltage of the battery is above a minimum threshold voltage.

18. The method of claim 16 , wherein:

the plurality of boost converter phases comprises a third boost converter phase comprising a third inductor, a third charge switch, and a third rectification switch; and

the method further comprises, when the battery management system is in the bypass mode, activating the third rectification switch and deactivating the third charge switch.