DC-powered system side control of AC-DC adapter primary side switching circuitry

• US 9,436,255 B2
• Filed: 11/18/2013
• Issued: 09/06/2016
• Est. Priority Date: 11/18/2013
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Verdun, Gary J.
• Primary Examiner(s): Abbaszadeh, Jaweed A
• Assistant Examiner(s): Hicks, Austin
• Application Number:
  US14/082,592
• Publication Number:
  US 20150143150A1
• Time in Patent Office: 1,023 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode

Abstract

Systems and methods are provided for enabling control of adapter primary side switching circuitry of an AC-DC adapter by a DC-powered information handling system that is connected to the AC-DC adapter for receiving DC power from the AC-DC adapter.

Claims

1. A system, comprising:

an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that is configured to receive power from the AC primary side switcher circuitry and to produce a DC power output therefrom;

a DC-powered information handling system coupled by a DC power connection to receive DC power from the DC power output of the AC-DC adapter system, the DC-powered information handling system comprising;

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state,

a battery system including one or more battery cells coupled to provide DC power to the system load, and

at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the second reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the DC secondary side of the AC-DC adapter system further comprises a capacitive element coupled between a transformer and a DC power output of the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter to enable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the first higher powered state, and to pulse operation of the AC primary side switcher circuitry on and off when the DC-powered information handling system is operating in the second reduced powered state in order to repeatedly allow the capacitive element to discharge to power DC secondary side control circuitry of the AC-DC adapter when the AC primary side circuitry is off and to recharge the output capacitive element when the AC primary side circuitry is on so as to continuously power DC secondary side control circuitry of the AC-DC adapter when the DC-powered information handling system is operating in the second reduced powered state.

2. The system of claim 1, where the at least one processing device of the DC-powered information handling system is coupled to transmit command signals to DC secondary side control circuitry of the AC-DC adapter to instruct the DC secondary side control circuitry to control the AC primary side switcher circuitry of the AC-DC adapter to selectably enable and disable operation of the AC primary side switcher circuitry.

3. The system of claim 1, where the at least one processing device of the DC-powered information handling system is coupled to transmit command signals across a power supplier identifier (PSID) data channel separate from the DC power connection to DC secondary side control circuitry of the AC-DC adapter to instruct the DC secondary side control circuitry to control the AC primary side switcher circuitry of the AC-DC adapter to selectably enable and disable operation of the AC primary side switcher circuitry.

4. The system of claim 1, where the system load of the DC-powered information handling system includes at least one second processing device that is configured to execute an operating system;

where the second processing device is configured to be active and to execute the operating system when the system load is operating in the first higher powered state; and

where the second processing device is configured to be inactive and not execute the operating system when the system load is operating in the second non-operational host power state.

5. A system, comprising:

an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that is configured to receive power from the AC primary side switcher circuitry and to produce a DC power output therefrom;

a DC-powered information handling system coupled by a DC power connection to receive DC power from the DC power output of the AC-DC adapter system, the DC-powered information handling system comprising;

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state,

a battery system including one or more battery cells coupled to provide DC power to the system load, and

at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the second reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from the AC-DC adapter system; and

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter to enable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the first higher powered state and to disable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the second reduced powered state;

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection when the DC-powered information handling system is coupled to receive DC power from the AC-DC adapter system; and

where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the DC-powered information handling system is operating in the second reduced powered state and the AC primary side switcher circuitry is disabled.

6. The system of claim 5, where the AC primary side switcher circuitry of the AC/DC adapter system is configured to be coupled to receive and control supply of power to the DC secondary side from an AC mains power supply;

and where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the DC-powered information handling system is operating in the second reduced powered state and the AC primary side switcher circuitry is disabled such that no AC mains current is consumed by the AC-DC adapter during the time DC power is provided across the DC power connection from the battery system to power the DC secondary side control circuitry.

7. A system, comprising:

an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that is configured to receive power from the AC primary side switcher circuitry and to produce a DC power output therefrom;

a DC-powered information handling system coupled by a DC power connection to receive DC power from the DC power output of the AC-DC adapter system, the DC-powered information handling system comprising;

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the second reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where no communication path exists for communicating adapter operation command signals from the DC-powered information handling system to the AC-DC adapter;

where the DC secondary side control circuitry of the AC-DC adapter is configured to sense power demand from the DC-powered information handling system on the DC power connection, and to disable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the power demand from the DC-powered information handling system drops below a minimum operating power threshold (PMIN) as a result of the system load transitioning from the first higher powered state to the second reduced power state;

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection;

where the at least one first processing device of the DC-powered information handling system is configured to sense voltage on the DC power connection; and

where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the at least one first processing device senses that a voltage on the DC power connection has dropped from a first normal operating voltage that occurs when the primary side switcher circuitry is operating, to below a first minimum voltage threshold that is less than the first normal operating voltage that occurs when the primary side switcher circuitry is disabled, the at least one first processing device of the DC-powered information handling system being configured to so control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter to maintain voltage on the DC power connection above a second minimum voltage threshold that is below the first minimum voltage threshold.

8. The system of claim 7, where the DC secondary side control circuitry of the AC-DC adapter is configured to sense voltage on the DC power connection;

where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to reduce or cease providing DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter such that the voltage on the DC power connection drops below the second minimum voltage threshold when the at least one first processing device senses that the system load of the DC-powered information handling system has entered the first higher powered state or determines that the system load of the DC-powered information handling system is ready to enter the first higher powered state; and

where the DC secondary side control circuitry of the AC-DC adapter is configured to enable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the DC secondary side control circuitry senses that the voltage on the DC power connection has dropped below the second minimum voltage threshold.

9. A DC-powered information handling system, comprising:

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state;

a battery system including one or more battery cells coupled to provide DC power to the system load; and

at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that receives power from the AC primary side switcher circuitry;

where the at least one first processing device of the DC-powered information handling system is configured when coupled to the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the DC secondary side of the AC-DC adapter system further comprises a capacitive element coupled between a transformer and a DC power output of the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter to enable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the first higher powered state, and to pulse operation of the AC primary side switcher circuitry on and off when the DC-powered information handling system is operating in the second reduced powered state in order to repeatedly allow the capacitive element to discharge to power DC secondary side control circuitry of the AC-DC adapter when the AC primary side circuitry is off and to recharge the output capacitive element when the AC primary side circuitry is on so as to continuously power DC secondary side control circuitry of the AC-DC adapter when the DC-powered information handling system is operating in the second reduced powered state.

10. The DC-powered information handling system of claim 9, where the at least one processing device of the DC-powered information handling system is configured to be coupled to transmit command signals to DC secondary side control circuitry of the AC-DC adapter to instruct the DC secondary side control circuitry to control the AC primary side switcher circuitry of the AC-DC adapter to selectably enable and disable operation of the AC primary side switcher circuitry.

11. The DC-powered information handling system of claim 9, where the system load of the DC-powered information handling system includes at least one second processing device that is configured to execute an operating system;

where the second processing device is configured to be active and to execute the operating system when the system load is operating in the first higher powered state; and

where the second processing device is configured to be inactive and not execute the operating system when the system load is operating in the second reduced power state.

12. A DC-powered information handling system, comprising:

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state;

a battery system including one or more battery cells coupled to provide DC power to the system load; and

at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that receives power from the AC primary side switcher circuitry;

where the at least one first processing device of the DC-powered information handling system is configured when coupled to the DC-powered information handling system to command circuitry of an AC-DC adapter so as to enable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the first higher powered state and to disable or pulse operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the second reduced powered state; and

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection when the DC-powered information handling system is coupled to receive DC power from the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to sense voltage on the DC power connection; and

where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the at least one first processing device senses that a voltage on the DC power connection has dropped from a first normal operating voltage that occurs when the primary side switcher circuitry is operating, to below a minimum voltage threshold that occurs when the primary side switcher circuitry is disabled.

13. A method of operating a DC-powered information handling system and an AC-DC adapter coupled to the DC-powered information handling system by a DC power connection, the method comprising:

providing the AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side;

receiving power in the DC secondary side from the AC primary side switcher circuitry and producing a DC power output from the DC secondary side;

providing the DC-powered information handling system having a system load, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the DC-powered information handling system being coupled by the DC power connection to receive DC power from the DC power output across the DC power connection;

operating the system load being in a first higher powered state and a second reduced power state;

operating the at least one first processing device of the DC-powered information handling system when the system load is operating in the second reduced power state;

using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state; and

where the DC secondary side of the AC-DC adapter system further comprises a capacitive element coupled between a transformer and a DC power output of the AC-DC adapter system; and

where the method further comprises using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter to enable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the first higher powered state, and to pulse operation of the AC primary side switcher circuitry on and off when the DC-powered information handling system is operating in the second reduced powered state in order to repeatedly allow the capacitive element to discharge to power DC secondary side control circuitry of the AC-DC adapter when the AC primary side circuitry is off and to recharge the output capacitive element when the AC primary side circuitry is on so as to continuously power DC secondary side control circuitry of the AC-DC adapter when the DC-powered information handling system is operating in the second reduced powered state.

14. The method of claim 13, further comprising using the at least one processing device of the DC-powered information handling system to transmit command signals to DC secondary side control circuitry of the AC-DC adapter to instruct the DC secondary side control circuitry to control the AC primary side switcher circuitry of the AC-DC adapter to selectably enable and disable operation of the AC primary side switcher circuitry.

15. The method of claim 13, further comprising using the at least one processing device of the DC-powered information handling system to transmit command signals across a power supplier identifier (PSID) data channel separate from the DC power connection to DC secondary side control circuitry of the AC-DC adapter to instruct the DC secondary side control circuitry to control the AC primary side switcher circuitry of the AC-DC adapter to selectably enable and disable operation of the AC primary side switcher circuitry.

16. The method of claim 13, where the system load of the DC-powered information handling system includes at least one second processing device configured to execute an operating system;

and where the method further comprises activating the second processing device to execute the operating system when the system load is operating in the first higher powered state; and

deactivating the second processing device not executing the operating system on the second processing device when the system load is operating in the second reduced power state.

17. A method of operating a DC-powered information handling system and an AC-DC adapter coupled to the DC-powered information handling system by a DC power connection, the method comprising:

providing the AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side;

receiving power in the DC secondary side from the AC primary side switcher circuitry and producing a DC power output from the DC secondary side;

providing the DC-powered information handling system having a system load, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the DC-powered information handling system being coupled by the DC power connection to receive DC power from the DC power output across the DC power connection;

operating the system load in a first higher powered state and a second reduced power state;

operating the at least one first processing device of the DC-powered information handling system when the system load is operating in the second reduced power state; and

using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter to enable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the first higher powered state and to disable operation of the AC primary side switcher circuitry when the DC-powered information handling system is operating in the second reduced powered state;

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection when the DC-powered information handling system is coupled to receive DC power from the AC-DC adapter system; and

where the method further comprises using the at least one first processing device of the DC-powered information handling system to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the DC-powered information handling system is operating in the second reduced powered state and the AC primary side switcher circuitry is disabled.

18. A method of operating a DC-powered information handling system and an AC-DC adapter coupled to the DC-powered information handling system by a DC power connection, the method comprising:

providing the AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side;

receiving power in the DC secondary side from the AC primary side switcher circuitry and producing a DC power output from the DC secondary side;

providing the DC-powered information handling system having a system load, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the DC-powered information handling system being coupled by the DC power connection to receive DC power from the DC power output across the DC power connection;

operating the system load in a first higher powered state and a second reduced power state;

operating the at least one first processing device of the DC-powered information handling system when the system load is operating in the second reduced power state;

using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where no communication path exists for communicating adapter operation command signals from the DC-powered information handling system to the AC-DC adapter;

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection when the DC-powered information handling system is coupled to receive DC power from the AC-DC adapter system, the method further comprising;

using the DC secondary side control circuitry of the AC-DC adapter to sense power demand from the DC-powered information handling system on the DC power connection, and to disable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the power demand from the DC-powered information handling system drops below a minimum operating power threshold (PMN) as a result of the system load transitioning from the first higher powered state to the second reduced power state;

using the at least one first processing device of the DC-powered information handling system to sense voltage on the DC power connection, and control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the at least one first processing device senses that a voltage on the DC power connection has dropped from a first normal operating voltage that occurs when the primary side switcher circuitry is operating, to below a first minimum voltage threshold that is less than the first normal operating voltage that occurs when the primary side switcher circuitry is disabled so as to maintain voltage on the DC power connection above a second minimum voltage threshold that is below the first minimum voltage threshold.

19. The method of claim 18, where the DC secondary side control circuitry of the AC-DC adapter is configured to sense voltage on the DC power connection;

and where the method further comprises;

using the at least one first processing device of the DC-powered information handling system to control the power switching circuitry to reduce or cease providing DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter such that the voltage on the DC power connection drops below the second minimum voltage threshold when the at least one first processing device determines that the system load of the DC-powered information handling system has entered the first higher powered state or determines that the system load of the DC-powered information handling system is ready to enter the first higher powered state; and

using the DC secondary side control circuitry of the AC-DC adapter to enable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the DC secondary side control circuitry senses that the voltage on the DC power connection has dropped below the second minimum voltage threshold.

20. A system, comprising:

an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that is configured to receive power from the AC primary side switcher circuitry and to produce a DC power output therefrom;

a DC-powered information handling system coupled by a DC power connection to receive DC power from the DC power output of the AC-DC adapter system, the DC-powered information handling system comprising;

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the second reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where no communication path exists for communicating adapter operation command signals from the DC-powered information handling system to the AC-DC adapter; and

where the DC secondary side control circuitry of the AC-DC adapter is configured to;

sense power demand from the DC-powered information handling system on the DC power connection, and to disable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the power demand from the DC-powered information handling system drops below a minimum operating power threshold (PMN) as a result of the system load transitioning from the first higher powered state to the second reduced power state; and

sense voltage on the DC power connection, and to enable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the DC secondary side control circuitry senses that the voltage on the DC power connection has dropped below the second minimum voltage threshold.

21. A system, comprising:

an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that is configured to receive power from the AC primary side switcher circuitry and to produce a DC power output therefrom;

a DC-powered information handling system coupled by a DC power connection to receive DC power from the DC power output of the AC-DC adapter system, the DC-powered information handling system comprising;

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the second reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection;

where the at least one first processing device of the DC-powered information handling system is configured to;

sense voltage on the DC power connection; and

where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the at least one first processing device senses that a voltage on the DC power connection has dropped from a first normal operating voltage that occurs when the primary side switcher circuitry is operating, to below a first minimum voltage threshold that is less than the first normal operating voltage that occurs when the primary side switcher circuitry is disabled, the at least one first processing device of the DC-powered information handling system being configured to so control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter to maintain voltage on the DC power connection above a second minimum voltage threshold that is below the first minimum voltage threshold; and

control the power switching circuitry to reduce or cease providing DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter such that the voltage on the DC power connection drops below the second minimum voltage threshold when the at least one first processing device senses that the system load of the DC-powered information handling system has entered the first higher powered state or determines that the system load of the DC-powered information handling system is ready to enter the first higher powered state.

22. A system, comprising:

an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that is configured to receive power from the AC primary side switcher circuitry and to produce a DC power output therefrom;

a DC-powered information handling system coupled by a DC power connection to receive DC power from the DC power output of the AC-DC adapter system, the DC-powered information handling system comprising;

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the second reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from the AC-DC adapter system;

where the at least one first processing device of the DC-powered information handling system is configured to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the at least one first processing device of the DC-powered information handling system is configured to monitor the real time charge of the battery system and;

cause operation of the AC primary side switcher circuitry be disabled for as long as the DC-powered information handling system is operating in the second reduced powered state if the monitored battery system charge is above a minimum battery capacity threshold; and

cause operation of the AC primary side switcher circuitry be pulsed for as long as the DC-powered information handling system is operating in the second reduced powered state if the monitored battery system charge is not above the minimum battery capacity threshold.

23. A DC-powered information handling system, comprising:

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state;

a battery system including one or more battery cells coupled to provide DC power to the system load; and

at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that receives power from the AC primary side switcher circuitry;

where the at least one first processing device of the DC-powered information handling system is configured when coupled to the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection;

where the at least one first processing device of the DC-powered information handling system is configured to;

sense voltage on the DC power connection; and

where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the at least one first processing device senses that a voltage on the DC power connection has dropped from a first normal operating voltage that occurs when the primary side switcher circuitry is operating, to below a first minimum voltage threshold that is less than the first normal operating voltage that occurs when the primary side switcher circuitry is disabled, the at least one first processing device of the DC-powered information handling system being configured to so control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter to maintain voltage on the DC power connection above a second minimum voltage threshold that is below the first minimum voltage threshold; and

control the power switching circuitry to reduce or cease providing DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter such that the voltage on the DC power connection drops below the second minimum voltage threshold when the at least one first processing device senses that the system load of the DC-powered information handling system has entered the first higher powered state or determines that the system load of the DC-powered information handling system is ready to enter the first higher powered state.

24. A DC-powered information handling system, comprising:

a DC-powered system load, the system load being configured to operate in a first higher powered state and a second reduced power state;

a battery system including one or more battery cells coupled to provide DC power to the system load; and

at least one first processing device separate from the system load, the at least one first processing device being configured to operate when the system load is operating in the reduced power state;

where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from an AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side that receives power from the AC primary side switcher circuitry;

where the at least one first processing device of the DC-powered information handling system is configured when coupled to the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the at least one first processing device of the DC-powered information handling system is configured to monitor the real time charge of the battery system and;

cause operation of the AC primary side switcher circuitry be disabled for as long as the DC-powered information handling system is operating in the second reduced powered state if the monitored battery system charge is above a minimum battery capacity threshold; and

cause operation of the AC primary side switcher circuitry be pulsed for as long as the DC-powered information handling system is operating in the second reduced powered state if the monitored battery system charge is not above the minimum battery capacity threshold.

25. A method of operating a DC-powered information handling system and an AC-DC adapter coupled to the DC-powered information handling system by a DC power connection, the method comprising:

providing the AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side;

receiving power in the DC secondary side from the AC primary side switcher circuitry and producing a DC power output from the DC secondary side;

providing the DC-powered information handling system having a system load, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the DC-powered information handling system being coupled by the DC power connection to receive DC power from the DC power output across the DC power connection;

operating the system load being in a first higher powered state and a second reduced power state;

operating the at least one first processing device of the DC-powered information handling system when the system load is operating in the second reduced power state;

using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the AC primary side switcher circuitry of the AC/DC adapter system is configured to be coupled to receive and control supply of power to the DC secondary side from an AC mains power supply; and

where the method further comprises using the at least one first processing device of the DC-powered information handling system to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the DC-powered information handling system is operating in the second reduced powered state and the AC primary side switcher circuitry is disabled such that no AC mains current is consumed by the AC-DC adapter during the time DC power is provided across the DC power connection from the battery system to power the DC secondary side control circuitry.

26. A method of operating a DC-powered information handling system and an AC-DC adapter coupled to the DC-powered information handling system by a DC power connection, the method comprising:

providing the AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side;

receiving power in the DC secondary side from the AC primary side switcher circuitry and producing a DC power output from the DC secondary side;

providing the DC-powered information handling system having a system load, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the DC-powered information handling system being coupled by the DC power connection to receive DC power from the DC power output across the DC power connection;

operating the system load being in a first higher powered state and a second reduced power state;

operating the at least one first processing device of the DC-powered information handling system when the system load is operating in the second reduced power state;

using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where no communication path exists for communicating adapter operation command signals from the DC-powered information handling system to the AC-DC adapter; and

where the method further comprises using the DC secondary side control circuitry of the AC-DC adapter to;

sense power demand from the DC-powered information handling system on the DC power connection, and to disable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the power demand from the DC-powered information handling system drops below a minimum operating power threshold (PMN) as a result of the system load transitioning from the first higher powered state to the second reduced power state; and

sense voltage on the DC power connection, and to enable the AC primary side switcher circuitry without receiving an adapter operation command signal from the DC-power information handling system when the DC secondary side control circuitry senses that the voltage on the DC power connection has dropped below the second minimum voltage threshold.

27. A method of operating a DC-powered information handling system and an AC-DC adapter coupled to the DC-powered information handling system by a DC power connection, the method comprising:

providing the AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side;

receiving power in the DC secondary side from the AC primary side switcher circuitry and producing a DC power output from the DC secondary side;

providing the DC-powered information handling system having a system load, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the DC-powered information handling system being coupled by the DC power connection to receive DC power from the DC power output across the DC power connection;

operating the system load being in a first higher powered state and a second reduced power state;

operating the at least one first processing device of the DC-powered information handling system when the system load is operating in the second reduced power state;

using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

where the DC-powered information handling system further comprises power switching circuitry coupled to control flow of DC current between the one or more battery cells of the battery system and the DC power connection;

where the method further comprises using the at least one first processing device of the DC-powered information handling system to;

sense voltage on the DC power connection; and

where the at least one first processing device of the DC-powered information handling system is configured to control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter when the at least one first processing device senses that a voltage on the DC power connection has dropped from a first normal operating voltage that occurs when the primary side switcher circuitry is operating, to below a first minimum voltage threshold that is less than the first normal operating voltage that occurs when the primary side switcher circuitry is disabled, the at least one first processing device of the DC-powered information handling system being configured to so control the power switching circuitry to provide DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter to maintain voltage on the DC power connection above a second minimum voltage threshold that is below the first minimum voltage threshold; and

control the power switching circuitry to reduce or cease providing DC power across the DC power connection from the battery system to power DC secondary side control circuitry of the AC-DC adapter such that the voltage on the DC power connection drops below the second minimum voltage threshold when the at least one first processing device senses that the system load of the DC-powered information handling system has entered the first higher powered state or determines that the system load of the DC-powered information handling system is ready to enter the first higher powered state.

28. A method of operating a DC-powered information handling system and an AC-DC adapter coupled to the DC-powered information handling system by a DC power connection, the method comprising:

providing the AC-DC adapter system having AC primary side switcher circuitry and a DC secondary side;

receiving power in the DC secondary side from the AC primary side switcher circuitry and producing a DC power output from the DC secondary side;

providing the DC-powered information handling system having a system load, a battery system including one or more battery cells coupled to provide DC power to the system load, and at least one first processing device separate from the system load, the DC-powered information handling system being coupled by the DC power connection to receive DC power from the DC power output across the DC power connection;

operating the system load being in a first higher powered state and a second reduced power state;

operating the at least one first processing device of the DC-powered information handling system when the system load is operating in the second reduced power state;

using the at least one first processing device of the DC-powered information handling system to command circuitry of the AC-DC adapter system so as to cause operation of the AC primary side switcher circuitry to remain in an enabled on condition for as long as the DC-powered information handling system is operating in the first higher powered state so as to maintain the adapter DC output voltage at a continuous non-zero operating voltage, and to disable or pulse operation of the AC primary side switcher circuitry for as long as the DC-powered information handling system is operating in the second reduced powered state;

further comprising using the at least one first processing device of the DC-powered information handling system to;

monitor the real time charge of the battery system;

cause operation of the AC primary side switcher circuitry be disabled for as long as the DC-powered information handling system is operating in the second reduced powered state if the monitored battery system charge is above a minimum battery capacity threshold; and

cause operation of the AC primary side switcher circuitry to be pulsed for as long as the DC-powered information handling system is operating in the second reduced powered state if the monitored battery system charge is not above the minimum battery capacity threshold.