POWER CONVERTER WITH REDUCED POWER CONSUMPTION WHEN TOGGLING BETWEEN SLEEP AND NORMAL MODES DURING DEVICE CHARGING

• US 20110128153A1
• Filed: 12/01/2009
• Published: 06/02/2011
• Est. Priority Date: 12/01/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sims, Nicholas A., Terlizzi, Jeffrey J.
• Granted Patent: US 8,830,073 B2
• Time in Patent Office: Days
• US Class Current: 340/636.1
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/325 Power saving in peripheral device

Abstract

Electronic devices may have batteries that power internal circuitry. A power converter may connect to an input-output port in an electronic device to deliver power to the electronic device. Battery charging circuitry in the electronic device may be used to charge the battery in an electronic device while power is delivered from the power converter. The power converter may have load detection circuitry. When an output load is present, the power converter operates in an active mode and delivers power to the electronic device. When the output load is not present, the power converter enters a low-power standby mode. The electronic device has switching circuitry that periodically either electrically couples or electrically isolates the input-output port from internal circuitry. When the input-output port is isolated, the power converter senses that no output load is present and enters the standby state to conserve power.

Claims

1. A method of operating an electronic device that receives power from a power converter that operates in a sleep mode and an active mode, comprising:

while the power converter is connected to the electronic device, periodically using circuitry in the electronic device to switch the power converter between the sleep mode and the active mode.

2. The method defined in claim 1 wherein periodically using the circuitry comprises sending digital data to the power converter using communications circuitry in the electronic device.

3. The method defined in claim 1 wherein the electronic device has an input-output port with electrical contacts and wherein periodically using the circuitry in the electronic device to switch the power converter between the sleep mode and the active mode comprises transmitting control signals to the power converter through at least a first of the electrical contacts, the method further comprising:

receiving power from the power converter through at least a second of the electrical contacts that is different than the first of the electrical contacts when the power converter is in the active mode.

4. The method defined in claim 1 wherein periodically using the circuitry comprises periodically opening and closing switching circuitry associated with an input-output port in the electronic device to present the power converter with an output load that alternates between being present and being absent.

5. An electronic device to which an alternating current (AC) to direct current (DC) power converter is selectively coupled, comprising:

a battery;

a connector to which output lines in the power converter are electrically connected; and

circuitry that is configured to;

receive power from the battery while electrically isolating the connector from the battery while the power converter is connected to the connector; and

receive power from the power converter through the output lines while electrically coupling the connector to the battery.

6. The electronic device defined in claim 5 wherein the circuitry comprises a voltage detector configured to monitor voltage on the battery to determine whether the battery has sufficient charge before electrically isolating the connector from the battery.

7. The electronic device defined in claim 5 further comprising a display in the circuitry that displays battery status information indicative of how much voltage is being produced by the battery.

8. A method of operating an electronic device that has a battery so that a power converter that is attached to the electronic device can periodically enter a low-power sleep state, comprising:

while powering the electronic device from the battery, electrically isolating the attached power converter from the electronic device using switching circuitry in the electronic device so that the attached power converter senses an absence of output loading and enters the low-power sleep state; and

when voltage on the battery falls below a given amount, electrically connecting the attached power converter to the electronic device using the switching circuitry so that the attached power converter senses that an output load is present and wakes from the low power sleep state to supply power to the electronic device.

9. The method defined in claim 8 wherein the electronic device has a voltage detector, the method further comprising monitoring the voltage on the battery to determine when the voltage on the battery falls below the given amount.

10. The method defined in claim 9 wherein the switching circuitry comprises at least one switch in a protection circuit coupled to an input-output port connector in the electronic device and wherein electrically isolating the attached power converter comprises opening the switch to electrically isolate circuitry within the electronic device from the input-output port connector.

11. The method defined in claim 9 further comprising:

monitoring the voltage on the battery to determine when the voltage on the battery has risen above a threshold voltage, wherein the threshold voltage is larger than the given amount.

12. The method defined in claim 8 further comprising:

while the voltage on the battery fluctuates between different values above the given amount, displaying a fixed battery charge level indicator on a display in the electronic device indicating that the battery is full.

13. An electronic device, comprising:

an input;

a battery producing a battery voltage;

circuitry coupled to the battery;

a switch circuit coupled to the input that is operable in an open state that electrically isolates the input from the circuitry and a closed state that electrically connects the input to the circuitry; and

a voltage detector in the circuitry that senses the battery voltage, wherein the circuitry is configured to;

open the switch circuit to electrically isolate the input whenever the voltage detector senses that the battery voltage exceeds a first threshold voltage; and

close the switch circuit to electrically connect the input to the circuitry whenever the voltage detector senses that the battery voltage has fallen below a second threshold, wherein the second threshold voltage is lower than the first threshold voltage.

14. The electronic device defined in claim 13 further comprising protection circuitry coupled to the input, wherein the switch circuit forms at least part of the protection circuitry.

15. The electronic device defined in claim 14 further comprising a charging circuit that receives power from the input when the switch circuit is closed and that charges the battery.

16. The electronic device defined in claim 13 further comprising a charging circuit that receives power from the input when the switch circuit is closed and that charges the battery.

17. The electronic device defined in claim 13 further comprising a display that displays a fixed battery charge status indicator while the battery voltage fluctuates within a range above the second threshold.

18. The electronic device defined in claim 13 further comprising:

an input connector at the input, wherein the input connector has a plurality of contacts, wherein the input connector is configured to receive power from a power converter that is connected to at least some of the contacts; and

communications circuitry in the circuitry that transmits digital data signals to the power converter though the contacts.

19. A method for operating a system that includes an electronic device with a connector and that includes a power converter that is sometimes connected to the connector and that is sometimes disconnected from the connector, the method comprising:

whenever the power converter is disconnected from the connector, using load detection circuitry in the power converter to detect an absence of an output load in the power converter and, in response to detection of the absence of the output load, placing the power converter in a sleep mode; and

whenever the power converter is connected to the electronic device periodically electrically isolating circuitry in the electronic device from the connector to which the power converter is connected while powering the circuitry with a battery.

20. The method defined in claim 19, wherein periodically electrically isolating the circuitry in the electronic device from the connector comprises:

periodically opening a switch to isolate the circuitry from the connector when the battery has a voltage above a given threshold voltage.