Synchronous power gauge
According to one exemplary embodiment, a synchronous power gauge is coupled to a processor for determining total charge consumed from a power source in an electronic device. The synchronous power gauge includes a controller for receiving a synch signal that indicates whether the electronic device is in an operating power mode or a low power mode. The synchronous power gauge further includes an analog to digital converter controlled by the controller and is configured to process a signal associated with current drawn from the power source when the electronic device is in the operating power mode. An accumulator coupled to the analog to digital converter maintains and updates a sum of digital outputs provided by the analog to digital converter when the electronic device is in the operating power mode. The processor uses the sum of digital outputs to determine the total charge consumed from the power source.
1. A synchronous power gauge coupled to a processor for determining total charge consumed from a power source in an electronic device, said synchronous power gauge comprising:
a controller receiving a synch signal, said synch signal indicating whether said electronic device is in an operating power mode or a low power mode;
a sigma-delta analog to digital converter controlled by said controller and configured to process a signal associated with current drawn from said power source when said electronic device is in said operating power mode;
an accumulator coupled to a digital output of said analog to digital converter, said accumulator maintaining and updating a sum of digital outputs provided by said analog to digital converter when said electronic device is in said operating mode;
said processor determining said total charge consumed from said power source.
2. The synchronous power gauge of claim 1 further comprising an ON-counter and an OFF-counter to aid said processor in determining power consumed from said power source during both said operating power mode and said low power mode.
3. The synchronous power gauge of claim 1 wherein said synch signal is in a first state when said electronic device is in said operating power mode and in a second state when said electronic device is in said low power mode.
4. The synchronous power gauge of claim 1 wherein said processor uses said total charge consumed from said power source to charge remaining in said power source.
5. The synchronous power gauge of claim 1 wherein said electronic device is selected from the group comprising a cellular telephone, a camera, a personal digital assistant, a lap top computer, a portable DVD, and an MP3 player.
6. The synchronous power gauge of claim 1 wherein said current drawn from said power source when said electronic device is in said operating power mode is up to approximately 1500 times greater than when said electronic device is in said low power mode.
7. The synchronous power gauge of claim 1 wherein said signal processed by said analog to digital converter is a voltage across a sense resistor.
8. The synchronous power gauge of claim 1 wherein said power source is a battery.
9. The synchronous power gauge of claim 2 wherein said ON-counter and said OFF-counter are read by said processor before either said ON-counter or said OFF-counter overflows.
10. A synchronous power gauge comprising:
a controller receiving a synch signal, said synch signal indicating whether an electronic device is in an operating power mode or a low power mode;
a sigma-delta analog to digital converter controlled by said controller and configured to receive a signal associated with current drawn from a power source when said electronic device is in said operating power mode;
an accumulator coupled to a digital output of said analog to digital converter, said accumulator maintaining and updating a sum of digital outputs provided by said analog to digital converter when said electronic device is in said operating power mode.
11. The synchronous power gauge of claim 10 wherein said synchronous power gauge is coupled to a processor, said processor receiving said sum of digital outputs to determine total charge consumed from said power source.
12. The synchronous power gauge of claim 10 wherein said synch signal is in a first state when said electronic device is in said operating power mode and in a second state when said electronic device is in said low power mode.
13. The synchronous power gauge of claim 10 wherein said electronic device is selected from the group comprising a cellular telephone, a camera, a personal digital assistant, a lap top computer, a portable DVD, and an MP3 player.
14. The synchronous power gauge of claim 10 wherein said signal processed by said analog to digital converter is a voltage across a sense resistor.
15. The synchronous power gauge of claim 10 wherein said power source is a battery.
16. The synchronous power gauge of claim 11 further comprising an ON-counter and an OFF-counter to aid said processor in determining power consumed from said power source during both said operating power mode and said low power mode.
17. The synchronous power gauge of claim 11 wherein said processor uses said total charge consumed from said power source to charge remaining in said power source.
18. The synchronous power gauge of claim 16 wherein said ON-counter and said OFF-counter are read by said processor before either said ON-counter or said OFF-counter overflows.