Integrated MEMS power-save switch

• US 20040183148A1
• Filed: 03/20/2003
• Published: 09/23/2004
• Est. Priority Date: 03/20/2003
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Blasko, Andrew Stephen III
• Granted Patent: US 6,833,597 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: H01H 2001/0042 Bistable switches, i.e. having two stable positions requiring only actuating energy for switching between them, e.g. with snap membrane or by permanent magnet
• CPC Class Codes: H01H 2300/022 Application wake up; switches or contacts specially provided for the wake up or standby shift of a circuit
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An integrated circuit (IC) chip provided with a ‘power-save’ switch, including MEMS (Micro-Electro-Mechanical Systems) switches in each power and ground ring, to be used to open the circuit and eliminate power drain. The MEMS switches preferably include a cantilevered beam deflected by an electrostatic charge. When the equipment of which the IC forms a part is put on standby, it enters a low-power mode in which the ‘power-save’ switch in each IC is actuated by a small control circuit that remains powered up. The MEMS switches are preferably latched into position at least when in the open position, for example by using an permanent magnet, so that no power is consumed by the open switches. The invention is applicable to chips used in wireless mobile terminals, where power consumption is critical, and in any application where it is necessary to enter a standby mode between uses.

Claims

1. A silicon substrate, comprising:

a plurality of integrated electronic components; and

a MEMS mechanical switch integrated in said silicon substrate together with said plurality of integrated electronic components, said mechanical switch being wired to open a power loop in at least one of said plurality of integrated electronic components to enter a low power mode.

2. The silicon substrate according to claim 1, further comprising:

a control circuit to automatically physically open said mechanical switch when said at least one of said plurality of integrated electronic components enters said low power mode, and to automatically physically close said mechanical switch when said at least one of said plurality of integrated electronic components enters a full power operating mode.

3. An integrated circuit provided with a power saving device, said integrated circuit comprising:

an operating circuit; and

a plurality of terminal connectors configured to be connected to said operating circuit;

said power saving device configured to connect said operating circuit to at least one of said terminal connectors when said integrated circuit is in an operating mode;

said power saving device configured to disconnect said operating circuit from said at least one of said terminal connectors when said integrated circuit is in a standby mode; and

said power saving device comprising at least one micromechanical switch interposed between said at least one of said terminal connectors and said operating circuit.

4. The integrated circuit according to claim 3, further comprising:

a control circuit responsive to a standby signal, said control circuit being configured to open said at least one micromechanical switch when said standby signal is present.

5. The integrated circuit according to claim 3, wherein:

said at least one micromechanical switch is configured to be actuated electrostatically.

6. The integrated circuit according to claim 3, wherein said microelectromechanical switch comprises:

a cantilevered beam; and

a conductive pad for contact with an end of said cantilevered beam.

7. The integrated circuit according to claim 6, wherein said at least one microelectromechanical switch further comprises:

a first contact;

a second contact opposing said first contact; and

latching means to hold said microelectromechanical switch in at least a position where said first contact does not electrically connect with said second contact.

8. The integrated circuit according to claim 7, wherein said latching means comprises:

a permanent magnet.

9. A power saving device comprising:

at least one microelectromechanical switch interposed between at least one terminal connector and an operating circuit;

wherein said power saving device is configured to connect said at least one terminal connector to said operating circuit in an operating mode of said power saving device; and

said power saving device is configured to disconnect said operating circuit from said at least one terminal connector in a low power mode of said power saving device.

10. The power saving device according to claim 9, further comprising:

a control circuit responsive to a standby signal, said control circuit being configured to open said at least one microelectromechanical switch when said standby signal is present.

11. The power saving device according to claim 9, wherein:

said at least one microelectromechanical switch is actuated using electrostatic energy.

12. The power saving device according to claim 9, wherein said microelectromechanical switch comprises a cantilevered beam.

13. The power saving device according to claim 9, wherein said at least one micromechanical switch further comprises:

a first contact;

a second contact opposing said first contact; and

latching means to hold said microelectromechanical switch in at least a position where said first contact does not connect with said second contact.

14. The power saving device according to claim 13, wherein said latching means comprises:

a permanent magnet.