Digital transmission circuit and method providing selectable power consumption via multiple weighted driver slices

• US 7,636,556 B2
• Filed: 01/16/2008
• Issued: 12/22/2009
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Carballo, Juan-Antonio, Nowka, Kevin John, Vo, Ivan, Yoo, Seung-moon
• Primary Examiner(s): Le; Nhan T
• Application Number:
  US12/015,458
• Publication Number:
  US 20080125062A1
• Time in Patent Office: 706 Days
• Field of Search: 455/68, 455/69, 455/127.1, 455/127.2, 455/127.5, 455/550.1, 455/552.1, 375/295
• US Class Current: 455/127.5
• CPC Class Codes: H04L 25/0272 Arrangements for coupling to multiple lines, e.g. for differential transmission
• CPC Class Codes: H04L 25/028 Arrangements specific to the transmitter end
• CPC Class Codes: H04L 25/0292 Arrangements specific to the receiver end

Abstract

A digital transmission circuit and method providing selectable power consumption via multiple weighted driver slices improves the flexibility of an interface while reducing power consumption when possible. A cascaded series of driver stages is provided by a set of parallel slices and a control logic that activates one or more of the slices, which combine to produce a cascaded active driver circuit. The power consumption/drive level selectability of the slice combination provides a driver that can be fine-tuned to particular applications to provide the required performance at a minimum power consumption level.

Claims

1. A method of controlling power consumption in a digital interface transmitter, comprising:

receiving an indication of that power consumption of said digital interface transmitter may be reduced; and

disabling one or more differently-weighted parallel driver slices in response to said indication to reduce said power consumption, wherein the driver slices have a common output node that connects the digital interface transmitter via at least one interface signal line conductor to a remote receiver for conducting a digital signal to the remote receiver.

2. The method of claim 1, wherein said disabling programs individual drive currents of each slice at each stage of said slice as a weight of different values to provide a range of selectable drive levels exceeding N:

1, where N is the number of said driver slices.

3. The method of claim 2, wherein said disabling programs said individual drive currents at each slice at each stage as a weight of powers of two, whereby a binary selection of transmitter current is provided.

4. The method of claim 2, wherein said disabling programs said individual drive currents at each slice at each stage by a weight of arbitrary factors, whereby a selection of transmitter current is provided in accordance with a discrete set of transmitter power requirements.

5. The method of claim 1, further comprising:

measuring a quality of an interface signal conducted by the at least one interface signal line conductor;

determining whether or not said quality is above a threshold level; and

in response to determining that said quality is above a threshold level, generating said indication.

6. The method of claim 5, wherein said measuring and determining are performed at the remote receiver, and wherein said method further comprises communicating a state of said indication to another receiver local to the digital interface transmitter, whereby said state of said indication is used to perform said disabling at said local side of said interface.

7. A method of controlling power consumption in a digital interface transmitter, comprising:

measuring a quality of an interface signal conducted by one or more interface signal line conductors connected to at least one output of the digital interface transmitter;

determining whether or not said quality is above a threshold level; and

in response to determining that said quality is above a threshold level, disabling one or more differently-weighted parallel driver slices of the digital interface receiver to reduce said power consumption, wherein said disabling programs individual drive currents of each slice at each stage of said slice as a weight of different values to provide a range of selectable drive levels exceeding N;

1, where N is the number of said driver slices, and wherein the driver slices have a common output node that connects the digital interface transmitter via at least one interface signal line conductor to a remote receiver for conducting a digital signal to the remote receiver.

8. The method of claim 7, wherein said measuring and determining are performed at the remote receiver, and wherein said method further comprises communicating a state of said indication to another receiver local to the digital interface transmitter, at a local side of said interface signal lines whereby said state of said indication is used to perform said disabling at said local side of said interface.

9. The method of claim 7, wherein said disabling programs said individual drive currents at each slice at each stage as a weight of powers of two, whereby a binary selection of transmitter current is provided.

10. The method of claim 7, wherein said disabling programs individual drive currents at each slice at each stage by a weight of arbitrary factors, whereby a selection of transmitter current is provided in accordance with a discrete set of transmitter power requirements.

11. A method of controlling power consumption in a digital interface transmitter, comprising:

measuring a quality of an interface signal conducted by at least one interface signal line conductor connected to at least one output of the digital interface transmitter, wherein the measuring is performed at a remote receiver connected to an opposite end the at least one interface signal line conductor;

determining whether or not said quality is above a threshold level; and

in response to determining that said quality is above a threshold level, disabling one or more differently-weighted parallel driver slices of the digital interface receiver to reduce said power consumption, wherein said disabling programs individual drive currents at each slice at each stage by a weight of arbitrary factors, whereby a selection of transmitter current is provided in accordance with a discrete set of transmitter power requirements and wherein said individual drive currents of each slice at each stage provide a range of selectable drive levels exceeding N;

1, where N is the number of said driver slices, and wherein the driver slices have a common output node that connects the digital interface transmitter via the at least one interface signal line conductor to a remote receiver for conducting a digital signal to the remote receiver.