Series and parallel hybrid switched capacitor networks for IC power delivery

• US 8,330,436 B2
• Filed: 06/30/2008
• Issued: 12/11/2012
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Oraw, Bradley S., Kamgaing, Telesphor
• Primary Examiner(s): Laxton, Gary L
• Assistant Examiner(s): Jackson, Lakaisha
• Application Number:
  US12/165,492
• Publication Number:
  US 20090322304A1
• Time in Patent Office: 1,625 Days
• Field of Search: 323/268, 323/269, 323/271, 323/272, 323/273, 323/282, 363/59, 363/60, 363/61, 363/62, 363/65, 363/74, 363/78, 363/123, 363/140, 363/147
• US Class Current: 323/268
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

Series switches for power delivery. A regulator operated as a current source is arranged in parallel with a switched capacitor divider. A switched capacitor divider is configured in series with a plurality of linear regulators with each regulating one of a plurality of voltage outputs from the switched capacitor divider. In another embodiment, a series switch bridge has a first pair of switches connected in series with a second pair of switches across a voltage input, each switch within a pair of switches is switched in-phase with the other while the first pair of switches is switched out of phase with the second pair of switches. A balancing capacitor is coupled across one switch in both the first and second pair to be in parallel when either of the pair of switches is closed to reduce a charge imbalance between the switches.

Claims

1. A power delivery network for an integrated circuit, the network comprising:

a hybrid parallel power conversion stage including a converter of a first type configured in parallel with a converter of a second type, the converter of the first type and the converter of the second type coupled to a same input voltage and to a same output circuit to provide a regulated output current to power the integrated circuit, wherein the converter of the first type is a switched capacitor converter and the converter of the second type is configured as a current source; and

a current controller coupled with at least the converter of the second type to increase a portion of the regulated output current provided by the converter of the second type relative to the switched capacitor converter in response to an increase in load current of the output circuit.

2. The power delivery network of claim 1, wherein the switched capacitor converter is a switched capacitor divider and wherein the converter of the second type is a buck regulator configured to operate in a current mode.

3. The power delivery network of claim 2, wherein the integrated circuit is a microprocessor, and the switched capacitor divider includes a plurality of low voltage logic MOSFETs configured in series across the input voltage.

4. The power delivery network of claim 1, wherein the switched capacitor converter is a switched capacitor divider and wherein the converter of the second type is a linear regulator configured to operate as a current source.

5. The power delivery network of claim 1, further comprising a voltage regulator stage configured in series with the hybrid parallel power conversion stage, wherein the voltage regulator stage output is coupled with an input to the hybrid parallel power conversion stage or the voltage regulator stage input is coupled with an output of the hybrid parallel power conversion stage.

6. The power delivery network of claim 5, wherein the voltage regulator stage further comprises at least one of a buck regulator or a linear regulator.

7. The power delivery network of claim 1, wherein the switched capacitor divider further comprises:

a plurality of FETs configured with a drain terminal coupled with a source terminal of an adjacent FET to be in series across a voltage input; and

a plurality of capacitors connected across the voltage input and coupled with the plurality of FETs to divide the input voltage.

8. The power deliver network of claim 7, wherein alternating ones of the plurality of FETs have gate terminals coupled together to form a first and second pair of gate coupled FETs, and wherein the first pair of gate coupled FETs is configured to switch between a low state and a high state within a switching cycle while the second pair of gate coupled FETs is configured to switch to a state opposite the first pair of gate coupled FETs;

and wherein the plurality of capacitors further comprise;

a first capacitor coupled to a drain terminal of each of the first pair of gate coupled FETs; and

a second capacitor coupled to a drain terminal of each of the second pair of gate coupled FETs.

9. The power delivery network of claim 1, wherein the converter of the first type is a switched capacitor converter with a switching frequency that remains constant for all loads with the regulated output current provided by the converter of the second type concurrently supplied with current provided by the switched capacitor converter to reduce load dependence of an output voltage of the hybrid parallel power conversion stage.

10. The power delivery network of claim 9, wherein the current controller sets a reference current in a buck converter with proportional control.

11. The power delivery network of claim 1, wherein the current controller is to increase the portion of the output current provided by the converter of the second type relative to that concurrently provided by the switched capacitor converter proportionally with the increase in load current.

12. The power delivery network of claim 1, wherein the current controller is to concurrently increase current provided by both the converter of the second type and the switched capacitor converter while increasing the portion of the regulated output current provided by the converter of the second type relative to the switched capacitor converter in response to an increase in load current of the output circuit.

13. A power delivery network for an integrated circuit, the network comprising:

a hybrid parallel power conversion stage including a converter of a first type configured in parallel with a converter of a second type, the converter of the first type and the converter of the second type coupled to a same input voltage and to a same output circuit to provide a regulated output current to power the integrated circuit, wherein the converter of the first type is a switched capacitor converter and the converter of the second type is configured as a current source;

an efficiency tracker to determine a feed-forward reference current based on a predetermined control relationship between the output current provided by the switched capacitor converter and by the converter of the second type for an input current to the hybrid parallel power conversion stage; and

a current controller, coupled with the efficiency tracker and at least the converter of the second type, to increase a portion of the output current provided by the converter of the second type relative to that provided by the switched capacitor converter based on at least a change in the feed-forward reference current responsive to an increase in the output circuit load current.

14. The power delivery network of claim 13, wherein the current controller is to supply the output current exclusively with the converter of the second type at loads above a first threshold current and is to supply the output current exclusively with the switched capacitor converter at loads below a second threshold current, which is equal to or less than the first threshold current.

15. The power delivery network of claim 14, wherein the conversion efficiency of the switched capacitor converter is approximately equal to that of the converter of the second type at the threshold current.

16. The power delivery network of claim 13, wherein the switched capacitor converter is a switched capacitor divider and wherein the converter of the second type is a buck regulator configured to operate in a current mode.

17. The power delivery network of claim 13, wherein the switched capacitor converter is a switched capacitor divider and wherein the converter of the second type is a linear regulator configured to operate as a current source.

18. A method of providing a regulated output current to power an integrated circuit, the method comprising:

receiving a same voltage input at each of a switched capacitor converter and a convertor of a second type;

supplying an output current, with at least one of the switched capacitor converter and a convertor of a second type, to a same output circuit driving a load;

determining a feed-forward reference current based on a predetermined control relationship between the output current supplied by the switched capacitor converter and by the converter of the second type for an input current to the hybrid parallel power conversion stage; and

increasing a portion of the output current provided by the converter of the second type relative to that provided by the switched capacitor converter based on at least a change in the feed-forward reference current in response to an increase in the load.

19. The method of claim 18, wherein supplying the output current further comprises:

switching a plurality of FETs having a drain terminal coupled with a source terminal of an adjacent FET to be in series across the voltage input, wherein the switching frequency remains constant for all loads; and

alternately charging and discharging a plurality of capacitors connected across the voltage input and coupled with the plurality of FETs to divide the input voltage down to an output voltage.

20. The method of claim 18, wherein increasing the portion of the output current supplied by the converter of the second type further comprises increasing the portion of the regulated output current proportionally with the increase in load current.

21. The method of claim 20, wherein supplying the output current further comprises supplying the output current exclusively with the converter of the second type at loads above a first threshold current and supplying the output current exclusively with the switched capacitor converter at loads below a second threshold current, which is equal to or less than the first threshold current.