Power management supply interface circuitry, systems and methods

• US 5,721,933 A
• Filed: 09/13/1996
• Issued: 02/24/1998
• Est. Priority Date: 12/22/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Walsh, James J., Kau, Weiyuen
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): Seto, Jeffrey K.
• Application Number:
  US08/712,659
• Time in Patent Office: 529 Days
• Field of Search: 395/750, 364/707, 307/31, 307/64, 307/66
• US Class Current: 713/300
• CPC Class Codes: G06F 1/1632 External expansion units, e.g. docking stations
• 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

Abstract

An electronic system (6) has a power management logic circuit (920). A first power supply connector (1902) is electrically coupled to the power management logic circuit (920) and a second power supply connector (1904) is also electrically coupled to the power management logic circuit (920). The power management logic circuit (920) has a first logic section (920A) connected to the first power supply connector (1902), and the first logic section (920A) has a suspend output (SUSPEND#). A second logic section (920B) is connected to the second power supply connector (1904) for operation independent of the first logic section (920A) when power is available at the second power supply connector (1904, RTCPWR) and suspended at the first power supply connector (1902, VCC).

Claims

1. An electronic system comprising:

a power management logic circuit;

a first power supply connector electrically coupled to said power management logic circuit and a second power supply connector electrically coupled to said power management logic circuit;

wherein said power management logic circuit comprises a first logic section connected to said first power supply connector, said first logic section having a suspend output, and a second logic section connected to said second power supply connector for operation independent of said first logic section when power is available at said second power supply connector and suspended at said first power supply connector.

2. An electronic system as claimed in claim 1 wherein said power management logic circuit has a power input and a control input, and said system further comprises a supply rail, a resistor connected between said power input and said control input, and a capacitor connected between said control input and said supply rail, said power management logic circuit further having a logic circuit adapted to turn off a main-on control signal in response to a voltage on said control input indicative of a failure of power.

3. An electronic system as claimed in claim 1 further comprising a first power supply connected to said first power supply connector and having a shutdown input connected to said suspend output of said power management circuit.

4. An electronic system as claimed in claim 3 further comprising an external connector and a resume circuit responsive to insertion of the external connector into an external system to produce a resume signal for said power management logic circuit.

5. An electronic system as claimed in claim 1 further comprising a temporary power cell connected to said second power supply connector.

6. An electronic system as claimed in claim 1 wherein said power management logic circuit has a suspend-resume input and comprises a logic section responsive to a state of said logic circuit to force said suspend-resume input to a predetermined level.

7. An electronic system comprising:

a power management logic circuit having a power input;

a first power supply connector electrically coupled to said power management logic circuit and a second power supply connector electrically coupled to said power management logic circuit; and

a power-channeling circuit, having at least two inputs and at least one output, said first and second power supply connectors coupled to said inputs and said power input coupled to said output.

8. An electronic system as claimed in claim 7 wherein said power-channeling circuit comprises a pair of diodes connected together and to said power input, said pair of diodes also connected separately to said first and second power supply connectors respectively.

9. An electronic system as claimed in claim 7 wherein said power management logic circuit has logic for system on/off responsive to a first control input, and said system further comprising an on/off switch coupled to said first control input.

10. An electronic system as claimed in claim 9 wherein said power management logic circuit has logic for suspension and resumption of operation responsive to a second control input, and said system further comprising a suspend/resume switch coupled to said second control input.

11. An electronic system as claimed in claim 7 wherein said power management logic circuit has a control input, and said system further comprising a suspend/resume switch coupled to said control input.

12. An electronic system comprising:

a power management logic circuit;

a first power supply connector electrically coupled to said power management logic circuit and a second power supply connector electrically coupled to said power management logic circuit;

wherein said first power supply connector has a battery-dead terminal and said power management logic circuit has a clock circuit and a logic circuit connected to said clock circuit and further having a control input coupled to said battery-dead terminal, said logic circuit responsive to a voltage at said battery-dead terminal indicative of a battery-dead condition to turn the system off upon the completion of at least one clock cycle of said clock circuit.

13. An electronic circuit as claimed in claim 12 further comprising a switch and wherein said first power supply connector also has a supply rail, and said system further comprises a transistor connected between said switch and said supply rail, said transistor controlled by a voltage at said battery-dead terminal to disconnect said switch from said supply rail when the voltage at said battery-dead terminal is indicative of a battery-dead condition.

14. An electronic system as claimed in claim 12 wherein said power management logic circuit comprises a first integrated circuit on a first chip and a second integrated circuit having the control input and said second integrated circuit provided on another chip coupled to the first integrated circuit.

15. An electronic system as claimed in claim 14 wherein said first integrated circuit is coupled to turn the system off upon the completion of at least one clock cycle of said clock circuit.

16. An integrated circuit for power management and having terminals and comprising:

a first logic section connected to a first voltage supply terminal, said first logic section having a suspend output; and

a second logic section connected to a second voltage supply terminal for operation independent of said first logic section when power is available at said second voltage supply terminal and suspended at said first voltage supply terminal.