Voltage regulator systems configured to control input voltage

1. A voltage regulator system comprising:

a regulator having an input terminal and an output terminal, wherein the regulator is configured to receive an input voltage from an adapter at the input terminal and provide an output voltage at the output terminal, wherein the regulator comprises at least one switched capacitor regulator configured to operate in at least a first conversion mode corresponding to a first conversion factor; and

a controller configured to control an operation of the regulator, wherein the controller is configured to determine when a conversion ratio of the regulator is greater than the first conversion factor by a threshold amount, and, in response, to send a request to the adapter to decrease the input voltage.

2. The voltage regulator system of claim 1 , wherein the at least one switched capacitor regulator comprises a reconfigurable switched capacitor regulator that is capable of operating in a plurality of conversion modes, wherein each of the plurality of conversion modes is associated with a unique conversion factor.

3. The voltage regulator system of claim 2 , wherein each of the plurality of conversion modes is associated with a unique integer conversion factor.

4. The voltage regulator system of claim 2 , wherein one of the plurality of conversion modes is associated with a non-integer conversion factor.

5. The voltage regulator system of claim 1 , wherein the at least one switched capacitor regulator is a part of a hybrid regulator that is capable of operating in a plurality of conversion modes, wherein each of the plurality of conversion modes is associated with a unique conversion factor.

6. The voltage regulator system of claim 5 , wherein the hybrid regulator further comprises a switched-inductor regulator.

7. The voltage regulator system of claim 1 , wherein the output terminal of the regulator is coupled to a battery to provide the output voltage to the battery.

8. The voltage regulator system of claim 7 , wherein the controller is configured to receive an instruction to increase a charging speed of the battery.

9. The voltage regulator system of claim 8 , wherein the instruction to increase the charging speed of the battery comprises an instruction to increase an output current of the regulator.

10. The voltage regulator system of claim 8 , wherein, in response to receiving the instruction to increase the charging speed, the controller is further configured to reconfigure the regulator to operate in a second conversion mode associated with a second conversion factor, wherein the second conversion factor is greater than the first conversion factor.

11. The voltage regulator system of claim 10 , wherein the controller is further configured to request the adapter to increase the input voltage received at the input terminal of the regulator.

12. The voltage regulator system of claim 11 , wherein the controller is configured to request the adapter to increase the input voltage received at the input terminal of the regulator until the conversion ratio is greater than the second conversion factor of the conversion mode.

13. The voltage regulator system of claim 1 , wherein the voltage regulator system is a part of a mobile device.

14. The voltage regulator system of claim 4 , wherein the voltage regulator system is implemented as a single integrated chip.

15. The voltage regulator system of claim 1 , wherein the controller is configured to send the request to the adapter over a wired interface.

16. The voltage regulator system of claim 15 , wherein the wired interface comprises a Universal Serial Bus (USB) Type C interface.

17. The voltage regulator system of claim 1 , wherein the controller is configured to send the request to the adapter by modulating the input voltage received at the input terminal.