Ultra low power wake-up circuit

• US 20070130479A1
• Filed: 12/01/2005
• Published: 06/07/2007
• Est. Priority Date: 12/01/2005
• Status: Active Grant

• Current Assignee: Cardinal Health Ireland Unlimited Company (Cardinal Health, Inc.)
• Original Assignee: Sherwood Services AG
• Inventors: Hernandez, Hector, Bisch, Michael, Price, Jeffrey, Forrest, Jeffrey
• Granted Patent: US 7,536,568 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G01K 2215/00 Details concerning sensor power supply
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/32 Means for saving power

Abstract

An apparatus for selectively enabling power including a power supply, and a device having a controller and an input activated by a user. The controller is selectively powered by the power supply. While the device is in a sleep state, a sensing circuit senses activation of the input by the user and enables the power supply to provide power to the controller in response to the sensed activation of the input by the user. A latch circuit causes the power supply to continue to provide power to the controller. The controller is responsive to the sensed activation of the input by the user for enabling the latch circuit and for disabling the latch circuit, thereby reentering the device into a sleep state.

Claims

1. An apparatus for selectively enabling power comprising:

a power supply

a device having a controller and an input activated by a user, said controller selectively powered by the power supply;

a sensing circuit for sensing activation of the input by the user and for enabling the power supply to provide power to the controller in response to the sensed activation of the input by the user;

a latch circuit for causing the power supply to continue to provide power to the controller; and

said controller responsive to the sensed activation of the input by the user for enabling the latch circuit and for disabling the latch circuit.

2. The apparatus of claim 1 further comprising:

a load switch responsive to a power supply enable signal for supplying power to the controller;

wherein the sensing circuit initially provides the power supply enable signal to the load switch in response to the sensed activation of the input by the user; and

wherein the latch circuit provides the power supply enable signal to the load switch while the latch circuit is enabled by the controller and discontinues providing the power supply enable signal when disabled by the controller.

3. The apparatus of claim 2 wherein the load switch is an array of load switches.

4. The apparatus of claim 2 wherein the power supply continuously provides power to the input activated by a user, the sensing circuit, and the latch circuit independent of the load switch.

5. The apparatus of claim 1 wherein the input activated by a user is a switch associated with a probe for providing input to the controller.

6. The apparatus of claim 1 wherein the input activated by a user is a switch associated with a cover for the device.

7. The apparatus of claim 1 wherein the device is a clinical thermometer, pulse meter, blood pressure monitor, predictive thermometer, or blood sugar monitor.

8. A method of selectively enabling a power supply of a device having a controller selectively powered by the power supply comprising:

sensing the activation of an input by a user of said device;

enabling the power supply to provide power to the controller in response to the sensed activation of the input by the user;

latching the enabled power supply to provide power to the controller during operation of the device; and

disabling the power supply to discontinue providing power to the controller.

9. The method of claim 8 wherein sensing the activation of an input by a user of said device comprises sensing the position of a switch of the device.

10. The method of claim 9 wherein enabling the power supply to provide power to the controller in response to the sensed activation of the input by the user comprises initially enabling the power supply.

11. The method of claim 10 wherein latching the enabled power supply to provide power to the controller during operation of the device comprises providing an enabling signal during operation of the controller.

12. The method of claim 11 wherein disabling the power supply to discontinue providing power to the controller after operation of the device has ended comprises discontinuing providing the enabling signal.

13. An apparatus for selectively enabling power comprising:

a power supply;

a device having a controller and an input activated by a user, said controller selectively powered by the power supply;

a sensing circuit for sensing activation of the input by the user and for enabling the power supply to provide power to the controller in response to the sensed activation of the input by the user; and

said controller responsive to the sensed activation of the input by the user for causing the sensing circuit to continue enabling the power supply to provide power to the controller during operation of the device and for causing the sensing circuit to disable the power supply from providing power to the controller.

14. The apparatus of claim 13 wherein the sensing circuit comprises a sensing microprocessor.

15. The apparatus of claim 13 further comprising:

a load switch responsive to a power supply enable signal for providing power to the controller; and

wherein the sensing circuit provides the power supply enable signal to the load switch in response to the sensed input by the user and/or in response to input from the controller.

16. The apparatus of claim 15 wherein the load switch is an array of load switches.

17. The apparatus of claim 15 wherein the power supply continuously provides power to the sensing circuit and the input activated by a user independent of the load switch.

18. The apparatus of claim 13 wherein the input activated by a user is a switch associated with a probe for providing input to the controller.

19. The apparatus of claim 13 wherein the input activated by a user is a switch associated with a cover for the device.

20. The apparatus of claim 13 wherein the device is a clinical thermometer, pulse meter, blood pressure monitor, predictive thermometer, or blood sugar monitor.