Method for efficient supply of power to a microcontroller

• US 7,386,740 B2
• Filed: 05/09/2005
• Issued: 06/10/2008
• Est. Priority Date: 10/30/2000
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Kutz, Harold, Snyder, Warren
• Primary Examiner(s): Patel, Nitin C.
• Application Number:
  US11/125,554
• Publication Number:
  US 20050198541A1
• Time in Patent Office: 1,128 Days
• Field of Search: 713/300, 713/310, 713/340, 327/530, 327/534, 327/536, 327/537
• US Class Current: 713/300
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A method and a system for supplying power to a microcontroller with a single cell. One embodiment of the present invention discloses incorporation of a power supply pump circuit with the microcontroller and their dynamic interaction. The microcontroller sends its power requirements to the power supply pump circuit and in response, the power supply pump circuit controls the operating voltage with optimal efficiency. The dynamic update of power supply pump circuit results in an efficient use of the power supply pump circuit and thus results in a reduction of the number of dry cell batteries to only a single cell. Incorporation of the microcontroller and power supply pump circuit onto a single chip reduces the pin number requirements as well as the space required on the printed circuit board.

Claims

1. A power supply pump circuit for supplying power to an integrated circuit comprising:

a battery circuit comprising an inductor;

a passive precharge circuit coupled to said battery circuit for causing said battery circuit to generate an initial operating voltage for said integrated circuit; and

a voltage sensor circuit for boosting said power from said initial operating voltage to a minimum operating voltage of said integrated circuit.

2. The power supply pump circuit of claim 1 further comprising:

a drive enable circuit coupled to receive commands from said voltage sensor circuit;

a gate drive boost circuit coupled to receive commands from said drive enable circuit to control said power supply voltage in accordance with said commands from said voltage sensor circuit; and

a transistor controlled by said gate drive boost circuit, said transistor coupled to said battery circuit such that a duty cycle of said transistor controls said power supply voltage.

3. The power supply pump circuit of claim 2 further comprising a ring oscillator circuit for generating a clock signal and coupled to send said clock signal to said drive enable circuit, said gate drive boost circuit and said voltage sensor circuit.

4. The power supply pump circuit of claim 2 wherein said voltage sensor circuit comprises a power on reset circuit storing a state that said integrated circuit is in at all times, wherein said power on reset circuit notifies said voltage sensor circuit to ramp said initial operating voltage to a minimum operating voltage of said integrated circuit when said state being an initializing state.

5. The power supply pump circuit of claim 2 wherein said drive enable circuit is coupled to said voltage sensor circuit for receiving power requirements from said integrated circuit and from said voltage sensor circuit and maintaining said power requirements of said integrated circuit.

6. The power supply pump circuit of claim 2 wherein said battery circuit includes only one dry cell battery.

7. The power supply pump circuit of claim 3, wherein said initial operating voltage is 1 Volt.

8. A power supply pump circuit for supplying power to a microcontroller comprising:

a battery circuit comprising an inductor and coupled to a voltage sensor;

a passive precharge circuit initially coupled to said battery circuit, said battery circuit supplying power to said passive precharge circuit causing an initial operating voltage; and

a Power On Reset circuit (POR), said POR circuit being a state dependent circuit memorizing a state of operation of said microcontroller, said POR circuit notifying said voltage sensor of said state of operation of said microcontroller, said voltage sensor coupled to a drive enable circuit and a gate drive boost circuit.

9. A power supply pump circuit of claim 8 wherein said microcontroller dynamically interacts with said power supply circuit when said initial operating voltage of said power supply pump circuit reaches a minimum operating voltage of said microcontroller.

10. A power supply pump circuit of claim 8 wherein said POR circuit communicates said state of operation of said microcontroller with said voltage sensor, said state being an initializing state or a wake up state, wherein said voltage sensor commands said drive enable to increase an initial operating voltage to a minimum operating voltage of said microcontroller.

11. A power supply pump circuit of claim 8 wherein said passive precharge circuit causes a reactive component to charge up to a level sufficient for said power supply pump circuit initial operation.

12. A power supply pump circuit of claim 8 wherein said microcontroller configures said voltage sensor circuit with desired parameters of said microcontroller when said minimum operating voltage is achieved.

13. A power supply pump circuit of claim 10 wherein said voltage sensor commands drive enable circuit a voltage level at least equal to a minimum operating voltage of said microcontroller if said state of said microcontroller received from said POR circuit is said initializing state.

14. A power supply pump circuit of claim 8 wherein said passive precharge circuit de-couples from said battery circuit when said initial operating voltage is achieved.

15. A power supply pump circuit of claim 8, wherein said microcontroller is in a sleep mode when said microcontroller is outside of an operating mode, power requirements of said microcontroller in said sleep mode is less than one nano amp.

16. A power supply pump circuit for supplying power to a microcontroller comprising:

a passive precharge circuit, a voltage sensor circuit, a drive enable circuit, a gate drive boost circuit and a transistor;

a battery circuit coupled to said passive precharge circuit;

said power supply pump circuit and said microcontroller residing in a single chip; and

said power supply pump circuit and said microcontroller electrically coupled to off-chip circuitry through a single pin.

17. A power supply pump circuit of claim 16 wherein said battery circuit is an off chip circuit.

18. A power supply pump circuit of claim 16 wherein said passive precharge circuit and said drive enable circuit allow said microcontroller to enter a low power sleep mode requiring one nano amp or less.

19. A power supply pump circuit of claim 16 wherein said passive precharge circuit is selectively decoupled from said power supply pump circuit.

20. A power supply pump circuit of claim 16 wherein said circuit interfaces with a plurality of input and output pins.