Granted Patent B2

US 8,692,520 · App. 13/233,949 · Granted Apr 8, 2014

Abstract

Claims (25)

1. A system for optimizing the current limiting behavior of a charger connected to a portable device, the system comprising:

a configuration module configured to set a maximum current limit and a register-based current limit values; and

a port power switch configured to limit the portable device current, in the event that the portable device current exceeds the maximum current limit value, the port power switch being configured to:

modify the portable device current to a predetermined constant current value upon a determination that the maximum current limit is less than the register-based current limit value; and

reset the portable device current to zero upon a determination that the maximum current limit is greater than the register-based current limit value.

2. The system of claim 1 , wherein the configurable module sets register-based current limit value for a plurality of charging profiles.

3. The system of claim 1 , wherein the configurable module sets maximum current limit value for a plurality of charging profiles.

4. The system of claim 2 , wherein the predetermined constant current value is set common to all the charging profiles.

5. The system of claim 1 , wherein the port power switch operates in a constant current mode when the portable device current is set to the predetermined constant current value.

6. The system of claim 1 , wherein the port power switch reduces its output voltage to less than the input voltage when the portable device current is set to the predetermined constant current value.

7. The system of claim 1 , wherein the predetermined constant current value is set greater than or equal to the maximum current limit value and set lower than or equal to the register-based current limit value.

8. The system of claim 1 , wherein the port power switch trips when the portable device current is reduced to zero.

9. The system of claim 1 , wherein register-based current limit value is stored in a digital register.

10. A method for optimizing the current limiting behavior of a battery charger, having a port power switch, which supports a plurality of charging profiles, the method comprising:

setting up a maximum current limit and register-based current limit values for the plurality of charging profiles;

applying a charging profile from the plurality of charging profiles to a portable device connected to the charger;

upon a determination that the portable device current exceeds the maximum current limit value, performing:

modifying the portable device current to a predetermined constant current value when the maximum current limit value is set below the register-based current limit value; or

modifying the portable device current to zero when the maximum current limit value is set greater than the register-based current limit value.

11. The method of claim 10 , wherein the predetermined constant current value is set common to all the charging profiles.

12. The method of claim 10 , wherein the applying step includes operating the port power switch in a constant voltage mode.

13. The method of claim 10 , wherein modifying the portable device current to the predetermined constant current value step includes operating the port power switch in a constant current mode.

14. The method of claim 10 , wherein modifying the portable device current to zero step includes tripping the port power switch.

15. The method of claim 10 , wherein modifying the portable device current to the predetermined constant current value step includes reducing the output voltage of the charger to less than the input voltage.

16. The method of claim 10 , wherein the predetermined constant current value is set greater than or equal to the maximum current limit value and set less than or equal to the register-based current limit value.

Assignments (10)