On-die switching power converter with stepped switch drivers and method

• US 6,559,492 B1
• Filed: 11/07/2001
• Issued: 05/06/2003
• Est. Priority Date: 11/07/2001
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Hazucha, Peter, Alvandpour, Atila
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): HO, TU TU V
• Application Number:
  US10/010,705
• Publication Number:
  US 20030085418A1
• Time in Patent Office: 545 Days
• Field of Search: 257/299, 257/691, 363/16, 363/123, 363/131
• US Class Current: 257/299
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

A DC-to-DC switching power converter includes switching elements having capacitive gate control inputs, an energy storage element and driver circuitry. Improved efficiency is achieved using adiabatic buffers to drive MOSFET switching elements with stepped switching signals. Substantially equal rise and fall times are achieved. In one embodiment, the switching power converter is fabricated on a semiconductor die to generate an output voltage to one or more functional unit blocks on the die.

Claims

1. A switching power converter comprising:

a driver portion to generate stepped switching signals, each stepped switching signal including at least one interim step between an initial state and a final state of a step; and

a switching portion to generate an output voltage in response to the stepped switching signals.

2. A switching power converter comprising:

a driver portion to generate stepped switching signals; and

a switching portion to generate an output voltage in response to the stepped switching signals, wherein the driver portion has at least one step driver stage comprised of step driver switching elements sequentially activated by control signals to generate one of the stepped switching signals.

3. The power converter as claimed in claim 2 wherein one of the step driver switching elements includes first and second switching transistors coupled back-to-back, the first switching transistor activated to generate a portion of an upward transition of the one stepped switching signal, the second switching transistor activated to generate a portion of a downward transition of the one stepped switching signal.

4. The power converter as claimed in claim 3 wherein the first switching transistor is an N-channel MOSFET and the second transistor is a P-channel MOSFET.

5. The power converter as claimed in claim 3 wherein the first switching transistor is also activated to generate the portion of the downward transition of the one stepped switching signal.

6. The power converter as claimed in claim 5 wherein the first and second switching transistors are both N-channel MOSFETs.

7. The power converter of claim 2 wherein the driver portion also has a predriver stage to generate the control signals for each of the step driver switching elements.

8. The power converter as claimed in claim 7 wherein in response to the control signals, the step driver switching elements sequentially couple input stepped voltages to generate the stepped switching signal.

9. A switching power converter comprising:

a driver portion to generate stepped switching signals, each stepped switching signal including at least one interim step between an initial state and a final state of a step; and

a switching portion to generate an output voltage in response to the stepped switching signals, wherein the switching portion is comprised of a plurality of switching elements and the driver portion is comprised of a plurality of step driver stages, wherein each switching element receives one of the stepped switching signals from a corresponding step driver stage.

10. The power converter as claimed in claim 9 wherein the switching elements of the switching portion include MOSFET switches.

11. The power converter as claimed in claim 9 wherein the switching portion further includes a capacitive energy storage element, the switching elements providing energy to and removing energy from the capacitive energy storage element in response to the stepped switching signals.

12. The power converter as claimed in claim 9 wherein the switching portion further includes an inductive energy storage element, the switching elements providing energy to and removing energy from the inductive energy storage element in response to the stepped switching signals.

13. A switching power converter comprising:

a driver portion to generate stepped switching signals; and

a switching portion to generate an output voltage in response to the stepped switching signals,

wherein the switching portion is comprised of a plurality of switching elements and the driver portion is comprised of a plurality of step driver stages, wherein each switching element receives one of the stepped switching signals from a corresponding step driver stage, and

wherein at least one of the step driver stages includes MOSFET switches to sequentially couple stepped voltages to generate one of the stepped switching signals for one of the switching elements of the switching portion.

14. A semiconductor die comprising:

an on-die power converter; and

at least one functional unit block to receive power from the on-die power converter,

wherein the on-die power converter includes a driver portion to generate stepped switching signals, each stepped switching signal including at least one interim step between an initial state and a final state of a step, and a switching portion to generate an output voltage for the at least one functional unit block in response to the stepped switching signals.

15. A semiconductor die comprising:

an on-die power converter; and

at least one functional unit block to receive power from the on-die power converter,

wherein the on-die power converter includes a driver portion to generate stepped switching signals, and a switching portion to generate an output voltage for the at least one functional unit block in response to the stepped switching signals,

wherein the driver portion has at least one step driver stage comprised of step driver switching elements sequentially activated by control signals to generate one of the stepped switching signals.

16. The semiconductor die as claimed in claim 15 wherein one of the step driver switching elements of the step driver stage includes first and second switching transistors coupled back-to-back, the first switching transistor activated to generate a portion of an upward transition of the one stepped switching signal, the second switching transistor activated to generate a portion of a downward transition of the one stepped switching signal.

17. The semiconductor die as claimed in claim 16 wherein the first switching transistor is also activated to generate the portion of the downward transition of the one stepped switching signal, and wherein the first and second switching transistors are both N-channel MOSFETs.

18. The semiconductor die as claimed in claim 16 further comprising at least a second functional unit block to receive power from another source.

19. The semiconductor die as claimed in claim 18 wherein the power converter reduces the voltage to the at least one functional unit block during a power conservation mode while the second functional unit block continues to receive power from the another source.

20. A buffer to generate a stepped switching signal comprising:

a first switching element to couple a lowest voltage of the stepped switching signal to an output;

second and third switching elements coupled back-to-back; and

a fourth switching element to couple a highest voltage of the stepped switching signal to the output,

wherein the second switching element turns on during a downward transition of the stepped switching signal to couple an interim voltage to the output, and the third switching element turns on during an upward transition of the stepped switching signal to couple the interim voltage to the output.

21. The buffer of claim 20 wherein the fourth switching element is a P-channel MOSFET, and the first, second and third switching elements are N-channel MOSFETs, and wherein the third switching element also turns on during the downward transition of the stepped switching signal to decrease a fall time of the downward transition to substantially equalize the fall and rise times of the stepped switching signal.

22. The buffer of claim 20 wherein the first and third switching elements are N-channel MOSFETs and the second and fourth switching elements are P-channel MOSFETs.

23. The buffer of claim 20 wherein the second, third and fourth switching elements are P-channel MOSFETs, and the first switching element is an N-channel MOSFET, and wherein the second switching element also turns on during the upward transition of the stepped switching signal to decrease a rise time of the upward transition to substantially equalize the rise and fall times of the stepped switching signal.