Power manager and power managing method for battery-powered application

• US 7,710,079 B2
• Filed: 07/19/2005
• Issued: 05/04/2010
• Est. Priority Date: 07/19/2005
• Status: Active Grant

• Current Assignee: Analog Devices International Unlimited Company (Analog Devices, Inc.)
• Original Assignee: Linear Technology Corporation (Analog Devices, Inc.)
• Inventors: Martin, Steven L., Nork, Samuel H., Simmons, David J., Zemke, Roger A., Barcelo, Trevor W.
• Primary Examiner(s): Assouad; Patrick J
• Assistant Examiner(s): Muralidar; Richard V
• Application Number:
  US11/183,960
• Publication Number:
  US 20070029975A1
• Time in Patent Office: 1,750 Days
• Field of Search: 320162-164, 320/141, 320/145, 320/152, 320157-159, 323/271, 363/80
• US Class Current: 320/164
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A power manager is configured to manage power for a battery-powered application. A power source, a load and a battery are interconnected through a circuit path. Power from the power source is provided to the load and battery by a switching regulator. Various implementations are presented.

Claims

1. A power manager for managing power for a battery-powered application, comprising:

a circuit path for interconnecting a power source, a load, and a battery;

a controller, provided between (a) the power source and (b) the load and the battery, configured for controlling power delivery through the circuit path to the load and battery, the load and the battery sharing the power supplied from the controller,

a first circuit configured for coupling a battery to the circuit path to charge the battery;

a second circuit configured for monitoring a voltage in the circuit path to detect whether the voltage exceeds both (1) a battery voltage plus a first reference and (2) a second reference; and

a third circuit configured for monitoring input current in the circuit path to detect whether the input current exceeds a current limit,

wherein the controller is coupled to the second and third circuits, and configured to limit the power delivery in response to a voltage or current detection by the second and third circuits, respectively.

2. The power manger according to claim 1, wherein the controller comprises:

a switching regulator for delivering power to the load and battery according to a switching pulse; and

a switching controller configured for terminating the switching pulse during a regulator switching cycle to establish, a regulator duty cycle based upon a detection by the second or third circuit.

3. The power manager according to claim 2, wherein

the second circuit is configured to determine an average voltage in the circuit path so as to compare the average voltage with both (1) the battery voltage plus the first reference and (2) the second reference, and

the third circuit is configured to determine an average input current in the circuit path so as to compare the average input current with the current limit.

4. The power manager according to claim 1, wherein when the third circuit detects that the input current exceeds the current limit, the controller limits the input current in the circuit path, causing a voltage in the circuit path to drop, and when the voltage in the circuit path drops to near a battery voltage, the first circuit is unable to deliver a programmed charge current to the battery and the load is prioritized to receive the current.

5. The power manager according to claim 4, wherein the first circuit is configured to provide current from the battery to the load when the voltage in the circuit path drops below the battery voltage.

6. The power manager according to claim 5, wherein the first circuit is configured to selectively operate as an ideal diode to provide the current from the battery to the load or operate as a battery charger.

7. The power manager according to claim 5, wherein the first circuit includes an ideal diode to provide the current from the battery to the load.

8. The power manager according to claim 1, wherein the first circuit is a constant-current/constant-voltage battery charger.

9. The power manager according to claim 1, wherein the first reference voltage varies depending on a program current.

10. A power managing method for a battery-powered application, comprising the steps of:

interconnecting a power source and a load through a circuit path to provide power from the power source to the load;

coupling a battery to the circuit path through a circuit configured for charging the battery;

controlling power delivery through the circuit path to the load and battery, the load and the battery sharing power delivered;

monitoring a voltage in the circuit path to detect whether the voltage exceeds both (a) a battery voltage plus a first reference voltage and (b) a second reference voltage; and

monitoring input current in the circuit path to detect whether the input current exceeds a current limit, wherein

the power delivery controlling step includes monitoring the voltage monitoring step and the input current monitoring step, and limiting the power delivery in response to a voltage or current detection by the voltage monitoring and input current monitoring steps, respectively.

11. The power managing method according to claim 10, wherein the circuit is a constant-current/constant-voltage battery charger.