Systems and methods for initializing a voltage bus and medical devices incorporating same

• US 8,614,596 B2
• Filed: 02/28/2011
• Issued: 12/24/2013
• Est. Priority Date: 02/28/2011
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Trock, Adam, Spurlin, Jon, Ortega, Michael, Kazarians, Seth
• Primary Examiner(s): Tran, Nguyen
• Assistant Examiner(s): DEMISSE, AFEWORK S
• Application Number:
  US13/036,984
• Publication Number:
  US 20120218023A1
• Time in Patent Office: 1,030 Days
• Field of Search: 327/198, 327/142, 327/143, 320127-136, 320/166, 320/167
• US Class Current: 327/198
• CPC Class Codes: H03K 17/22 Modifications for ensuring a predetermined initial state when the supply voltage has been applied bi-stable generators H03K3/12
• CPC Class Codes: H03K 17/28 Modifications for introducing a time delay before switching modifications to provide a choice of time-intervals for executing more than one switching action H03K17/296

Abstract

Systems, apparatus, and methods are provided for initializing a voltage bus. An exemplary system includes an input interface, a voltage bus, discharge circuitry coupled to the voltage bus, connection circuitry coupled between the voltage bus and the input interface, and a control module coupled to the connection circuitry and the discharge circuitry. The control module activates the discharge circuitry prior to activating the connection circuitry.

Claims

1. A system, comprising:

an input interface including a first node and a second node;

a voltage bus including a first voltage rail and a second voltage rail coupled to the second node, the voltage bus having a bus voltage between the first voltage rail and the second voltage rail;

discharge circuitry coupled electrically parallel between the first voltage rail and the second voltage rail;

connection circuitry coupled between the first voltage rail and the first node; and

a control module coupled to the connection circuitry and the discharge circuitry to;

identify a connection condition; and

in response to the connection condition;

activate the discharge circuitry in response to identifying the bus voltage is less than an upper threshold voltage prior to activating the connection circuitry; and

after activating the discharge circuitry, activate the connection circuitry after the bus voltage is discharged below a lower threshold voltage.

2. The system of claim 1, wherein the connection condition is indicative of a desire to activate the connection circuitry.

3. The system of claim 1, wherein a first time period after activating the discharge circuitry, the control module:

deactivates the discharge circuitry; and

activates the connection circuitry.

4. The system of claim 3, wherein the discharge circuitry discharges the bus voltage to a voltage less than the lower threshold voltage within the first time period prior to being deactivated.

5. The system of claim 1, wherein the control module deactivates the discharge circuitry after activating the discharge circuitry and prior to activating the connection circuitry.

6. The system of claim 1, wherein after activating the discharge circuitry, the control module:

deactivates the discharge circuitry in response to detecting the bus voltage is less than the lower threshold voltage; and

activates the connection circuitry after deactivating the discharge circuitry.

7. The system of claim 1, wherein:

the discharge circuitry is coupled electrically parallel between the first voltage rail and the second voltage rail; and

the connection circuitry includes a first switching element coupled between the first node and the first voltage rail.

8. The system of claim 7, wherein the control module:

identifies the connection condition by detecting a voltage at the first node of the input interface that is greater than a threshold voltage indicative of a power supply being coupled to the input interface; and

in response to detecting the voltage at the first node is greater than the threshold voltage;

activates the discharge circuitry for a first time period in response to identifying the bus voltage is less than the upper threshold voltage; and

after the first time period;

deactivates the discharge circuitry; and

activates the first switching element.

9. The system of claim 8, wherein:

the discharge circuitry includes;

a second switching element; and

a resistive element, the resistive element and the second switching element being configured electrically in series between the first voltage rail and the second voltage rail; and

the control module;

activates the discharge circuitry by activating the second switching element for the first time period in response to detecting the voltage at the first node is greater than the threshold voltage, the resistive element being configured electrically parallel between the first voltage rail and the second voltage rail when the second switching element is activated; and

deactivates the discharge circuitry by deactivating the second switching element after the first time period.

10. The system of claim 9, wherein the resistive element discharges the voltage bus to a voltage less than the lower threshold voltage within the first time period.

11. The system of claim 1, wherein the control module detects the connection condition when a voltage at the input interface is indicative of a power supply being coupled to the input interface.

12. The system of claim 1, wherein the lower threshold voltage corresponds to a lower power-on reset threshold voltage for an electronic component coupled to the voltage bus and the upper threshold voltage corresponds to an upper power-on reset threshold voltage for the electronic component.

13. The system of claim 12, wherein in response to identifying the connection condition, the control module activates the connection circuitry while maintaining the discharge circuitry in a deactivated state in response to identifying the bus voltage is greater than the upper threshold voltage.

14. A method for initializing a voltage bus having a bus voltage, the method comprising:

identifying a connection condition indicative of a desire to provide a power supply voltage from a power supply to the voltage bus; and

in response to identifying the connection condition;

discharging the voltage bus in response to identifying the bus voltage is less than an upper threshold voltage; and

after discharging the voltage bus until the bus voltage is less than a lower threshold voltage, activating connection circuitry coupled between the power supply and the voltage bus to provide the power supply voltage to the voltage bus.

15. The method of claim 14, wherein discharging the voltage bus comprises activating discharge circuitry coupled to the voltage bus in response to identifying the connection condition.

16. The method of claim 15, further comprising:

identifying a disconnection condition after activating the connection circuitry; and

in response to identifying the disconnection condition;

deactivating the connection circuitry; and

maintaining the discharge circuitry in a deactivated state.

17. The method of claim 14, wherein activating the connection circuitry comprises activating the connection circuitry after the bus voltage is less than the lower threshold voltage.

18. The method of claim 17, wherein discharging the voltage bus comprises:

activating discharge circuitry coupled to the voltage bus in response to identifying the connection condition; and

deactivating the discharge circuitry after the bus voltage is less than the lower threshold voltage.

19. The method of claim 18, wherein activating the connection circuitry comprises activating the connection circuitry after deactivating the discharge circuitry.

20. The method of claim 15, further comprising maintaining the discharge circuitry in a deactivated state prior to identifying the connection condition.

21. A method for initializing a voltage bus of a portable medical device, the voltage bus having a bus voltage, the method comprising:

identifying a connection condition; and

in response to identifying the connection condition;

when the bus voltage is greater than a first threshold voltage, activating connection circuitry coupled between a power supply and the voltage bus; and

when the bus voltage is less than the first threshold voltage;

discharging the voltage bus until the bus voltage is less than a second threshold voltage; and

activating the connection circuitry after the bus voltage is less than the second threshold voltage.

22. The method of claim 21, wherein discharging the voltage bus comprises activating discharge circuitry coupled to the voltage bus in response to identifying the connection condition.

23. The method of claim 22, wherein activating the connection circuitry when the bus voltage is greater than the first threshold voltage further comprises maintaining the discharge circuitry deactivated.

24. The method of claim 21, wherein identifying the connection condition comprises detecting insertion of the power supply into the portable medical device.

25. The method of claim 24, the connection circuitry being coupled between the voltage bus and an input interface to be coupled to the power supply, wherein detecting insertion of the power supply comprises detecting a voltage at the input interface that is greater than a third threshold voltage.

26. The method of claim 21, wherein identifying the connection condition comprises receiving signals indicative of a desire to turn on the portable medical device.

27. A portable medical device, comprising:

an interface to be coupled to a power supply;

an electronics system including;

a voltage bus having a bus voltage;

connection circuitry coupled between the voltage bus and the interface;

discharge circuitry coupled to the voltage bus; and

a control module coupled to the connection circuitry and the discharge circuitry, wherein the control module;

identifies a connection condition indicative of a desire to provide a power supply voltage from the power supply to the voltage bus; and

in response to identifying the connection condition;

activates the discharge circuitry for a first time period in response to identifying the bus voltage is less than an upper threshold voltage to discharge the bus voltage to less than a lower threshold voltage; and

thereafter activates the connection circuitry to provide the power supply voltage to the voltage bus.

28. The portable medical device of claim 27, further comprising an electronic component coupled to the voltage bus, wherein:

the lower threshold voltage comprises a lower power-on reset threshold voltage for the electronic component; and

the discharge circuitry discharges the bus voltage to the voltage less than the lower power-on reset threshold voltage for the electronic component within the first time period after being activated.

29. The portable medical device of claim 28, the upper threshold voltage comprising an upper power-on reset threshold voltage for the electronic component, wherein in response to identifying the connection condition when the bus voltage is greater than the upper power-on reset threshold voltage for the electronic component prior to activating the discharge circuitry, the control module activates the connection circuitry while maintaining the discharge circuitry deactivated.

30. The portable medical device of claim 27, wherein the control module is coupled to the interface, and the control module identifies the connection condition in response to detecting the power supply coupled to the interface.

31. The portable medical device of claim 27, wherein the control module is coupled to the interface, and the control module:

identifies the connection condition when a voltage at the interface is greater than a threshold voltage; and

activates the connection circuitry if the voltage at the interface is greater than the threshold voltage after the first time period.