Power management supply interface circuitry, systems and methods

• US 5,781,780 A
• Filed: 07/17/1996
• Issued: 07/14/1998
• 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): Sheikh, Ayaz R.
• Assistant Examiner(s): Etienne, Ario
• Application Number:
  US08/682,460
• Time in Patent Office: 727 Days
• Field of Search: 395/750, 395/750.01-750.08
• 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).

Other devices, systems and methods are also disclosed.

Claims

1. A personal computer comprising:

an input device;

a memory;

a display;

a first integrated circuit having a microprocessor coupled to an input device, said memory, and said display;

a second integrated circuit coupled to said microprocessor having a power management logic circuit;

a first power supply connecter 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, having a suspend/resume switch input and a on switch input, and wherein a transistor is controlled by a voltage at a battery-dead terminal and is connected between both switches and a ground supply rail such that both switches are disconnected from said ground supply rail upon receipt of a battery-dead indication.

2. A personal computer as claimed in claim 1 wherein said second logic section of 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. A personal computer 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. A personal computer 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. A personal computer as claimed in claim 1 further comprising a temporary power cell connected to said second power supply connector.

6. A personal computer 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. A personal computer as claimed in claim 1 wherein said input device includes a keyboard.

8. A personal computer as claimed in claim 1 wherein said display includes a CRT.

9. A personal computer as claimed in claim 1 wherein said personal computer has the form of a notebook computer.