Circuit and method for powering up an integrated circuit and an integrated circuit utilizing same

• US 8,253,452 B2
• Filed: 02/21/2006
• Issued: 08/28/2012
• Est. Priority Date: 02/21/2006
• Status: Active Grant

• Current Assignee: Spansion Israel Limited (Infineon Technologies AG)
• Original Assignee: Spansion Israel Limited (Infineon Technologies AG)
• Inventors: Kushnarenko, Alexander
• Primary Examiner(s): TRA, ANH QUAN
• Application Number:
  US11/357,081
• Publication Number:
  US 20070194835A1
• Time in Patent Office: 2,380 Days
• Field of Search: 327/143, 327/198, 327/539
• US Class Current: 327/143
• CPC Class Codes: G05F 3/30 Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities G05F3/26 takes precedence

Abstract

The present invention is a circuit and method for providing a reference voltage and/or one or more circuit/circuit-block enabling signals for an IC. As the voltage level on a power supply line ramps upward towards or above a nominal operating voltage, a first threshold voltage detector circuit segment may be activated and may begin to generate a bandgap reset signal once the voltage level of the power supply reaches a first threshold voltage level. The bandgap reset signal may trigger the power-up and operation of a bandgap reference circuit segment, and according to further embodiments of the present invention, a second threshold voltage detector circuit segment, which second threshold voltage detector circuit segment may be matched with the first voltage detector circuit, may generate a voltage reset signal indicating that the bandgap reference source is powering-up. Once the supply voltage reaches a third threshold reference voltage, the first detector may disable the bandgap reset.

Claims

1. A method of providing a reference voltage to an integrated circuit (“

IC”

) comprising;

i generating a bandgap reset signal and a voltage reset signal once a supply voltage of the IC reaches a first threshold voltage level;

ii disabling the bandgap reset signal once the supply voltage reaches a second threshold voltage level, which second threshold voltage level is sufficient for an associated bandgap reference circuit segment to produce a substantially stable reference voltage; and

iii modulating the voltage-reset signal once the supply voltage reaches a third threshold voltage so as to indicate that the bandgap reference circuit segment is operational.

2. The method according to claim 1, wherein the third threshold voltage is greater than the second threshold voltage by some voltage margin value.

3. The method according to claim 2, wherein the voltage margin value is selected such that once the supply voltage reaches the third threshold value the bandgap reference circuit segment has substantially established a steady state output.

4. The method according to claim 1, wherein the third threshold voltage is substantially equal to the second threshold voltage.

5. The method according to claim 1, wherein as part of generating a voltage reset signal an input node of a logic device is pulled to down to ground.

6. The method according to claim 5, wherein as part of modulating the voltage reset signal, the input node of the logic device is pulled up to the supply voltage level.

7. The method according to claim 1, wherein as part of generating a bandgap reset signal an input node of a logic device is pulled to down to ground.

8. The method according to claim 7, wherein as part of disabling the bandgap reset signal the input node of the logic device is pulled up to the supply voltage.

9. A circuit for providing a reference voltage to an integrated circuit (“

IC”

) comprising;

i a first voltage threshold detection circuit segment adapted to generate a bandgap reset signal once a supply voltage of the IC reaches a first threshold voltage level and to disable the bandgap reset signal once the supply voltage reaches a second threshold voltage level, which second threshold voltage level is sufficient for an associated bandgap reference circuit segment to produce a substantially stable reference voltage, and

ii a second voltage threshold detection circuit segment adapted to generate a voltage reset signal once the supply voltage of the IC reaches the first threshold voltage level and to modulate the voltage reset signal once the supply voltage reaches a third threshold voltage level so to indicate that the bandgap reference is operational.

10. The circuit according to claim 9, wherein said first voltage threshold detection circuit segment comprises two or transistor mirrors and a logic device.

11. The circuit according to claim 9, wherein said second voltage threshold detection circuit segment comprises two or transistor mirrors and a logic device.

12. The circuit according to claim 9, further comprising a bangap reference follower circuit segment.

13. The circuit according to claim 12, wherein said bandgap reference follower includes a voltage offset element adapted to introduce a voltage margin between the first and second threshold voltages.

14. An integrate circuit comprising:

i non-volatile memory circuitry;

ii a first voltage threshold detection circuit segment adapted to generate a bandgap reset signal once a supply voltage of the IC reaches a first threshold voltage level and to disable the bandgap reset signal once the supply voltage reaches a second threshold voltage level, which second threshold voltage level is sufficient for an associated bandgap reference circuit segment to produce a substantially stable reference voltage,

iii a second voltage threshold detection circuit segment adapted to generate a voltage reset signal once the supply voltage of the IC reaches the first threshold voltage level and to modulate the voltage reset signal once the supply voltage reaches a third threshold voltage level so to indicate that the bandgap reference is operational; and

iv wherein said non-volatile memory circuitry utilizes an output signal from the bandgap reference circuit segment.

15. The circuit according to claim 14, wherein said first voltage threshold detection circuit segment comprises two or transistor mirrors and a logic device.

16. The circuit according to claim 14, wherein said second voltage threshold detection circuit segment comprises two or transistor mirrors and a logic device.

17. The circuit according to claim 14, further comprising a bangap reference follower circuit segment.

18. The circuit according to claim 17, wherein said bandgap reference follower includes a voltage offset element adapted to introduce a voltage margin between the first and second threshold voltages.