Current recycling circuit and a method of current recycling

• US 6,552,581 B1
• Filed: 08/25/2000
• Issued: 04/22/2003
• Est. Priority Date: 08/25/2000
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Gabara, Thaddeus John
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): ENGLUND, TERRY LEE
• Application Number:
  US09/648,162
• Time in Patent Office: 970 Days
• Field of Search: 327/215, 327/108, 327/185, 327/544, 327/595, 327/519, 330/251, 307/36, 307/37, 307/54, 307/61, 307/63, 307/71, 307/77
• US Class Current: 327/108
• CPC Class Codes: H03K 19/0019 by energy recovery or adiabatic operation

Abstract

A process and circuitry for drawing current from a power source to produce a first operation, such as a Boolean operation, and reusing the current to generate a further operation. In other words, the current from the first operation may be used to perform a second or subsequent operation. This process is referred generally herein as current recycling.

Claims

1. A circuit comprising:

a first current steering stage;

at least a second current steering stage;

the first current steering stage, comprising a low voltage differential swing circuit, using a first current to drive a first output in respect to a first input; and

the second current steering stage, using a second current from the first current steering stage, configured to drive a second output in respect to a second input.

2. The circuit of claim 1 wherein the second current steering stage comprises a further low voltage differential swing circuit.

3. The circuit of claim 1 wherein the first current steering stage operates at a first common mode voltage and the second current steering stage operates at a second common mode voltage different than the first common mode voltage.

4. The circuit of claim 3 wherein the first common mode voltage is greater than the second common mode voltage.

5. The circuit of claim 1 wherein the second current steering stage comprises at least two current steering stages each receiving a portion of the second current.

6. A circuit comprising:

a first circuit, including a first current steering stage comprising a low voltage differential swing circuit, adapted to receive a first supply current; and

a second circuit adapted to receive a second supply current only from the first circuit;

the first circuit adapted to produce a first output in response to a first input and the second circuit adapted to produce a second output in response to a second input.

7. The circuit of claim 6 wherein the second circuit is adapted to receive a portion of the first supply current.

8. The circuit of claim 7 wherein the first circuit is a first line driver.

9. The circuit of claim 8 wherein the second circuit is a second line driver.

10. The circuit of claim 8 wherein the second circuit is other than a line driver.

11. The circuit of claim 6 wherein the second circuit is a line driver.

12. The circuit of claim 6 wherein the second circuit comprises at least two separate circuits each receiving a portion of the second supply current.

13. A process for operating circuitry comprising

(a) providing a current to a first circuit including a first current steering stage comprising a low voltage differential swing circuit;

(b) using, by the first circuit, the current for providing a first output in respect to a first input;

(c) providing the current to a second circuit different from the first circuit; and

(d) using, by the second circuit, the current for providing a second output in respect to a second input.

14. The process of claim 13 wherein step (b) is performed prior to step (d).

15. The process of claim 14 wherein the first circuit is a line driver.

16. The process of claim 15 wherein the second circuit is a further line driver.

17. The process of claim 15 wherein the second circuit performs a Boolean operation.

18. The process of claim 13 wherein the second circuit is a line driver.

19. The process of claim 13 wherein the second circuit comprises at least two separate circuits where step (d) further comprises:

using, by the at least two separate circuits, a portion of the current.