Apparatus and method for recovery of wasted power from differential drivers

• US 20080278224A1
• Filed: 06/19/2007
• Published: 11/13/2008
• Est. Priority Date: 05/07/2007
• Status: Active Grant

• Current Assignee: Analogix Semiconductor, Inc. (Beijing Shanhai Capital Management Co., Ltd.)
• Original Assignee: Analogix Semiconductor, Inc. (Beijing Shanhai Capital Management Co., Ltd.)
• Inventors: Chi, Hongwu
• Granted Patent: US 8,035,359 B2
• Time in Patent Office: Days
• US Class Current: 327/541
• CPC Class Codes: H03F 2203/45008 the addition of two signals being made by a resistor addition circuit for producing the common mode signal
• CPC Class Codes: H03F 2203/45466 the CSC being controlled, e.g. by a signal derived from a non specified place in the dif amp circuit
• CPC Class Codes: H03F 2203/45506 the CSC comprising only one switch
• CPC Class Codes: H03F 2203/45654 the LC comprising one or more extra diodes not belonging to mirrors
• CPC Class Codes: H03F 2203/45696 the LC comprising more than two resistors
• CPC Class Codes: H03F 3/45183 Long tailed pairs H03F3/4521, H03F3/45237 take precedence
• CPC Class Codes: H03K 19/0019 by energy recovery or adiabatic operation
• CPC Class Codes: H04L 25/0264 Arrangements for coupling to transmission lines duplexing arrangements H04L5/14; line equalisers, line build-out devices H04L25/03878
• 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

Abstract

An apparatus and method for supplying power to circuits of an integrated circuit (IC) from the wasted power in low-swing high-speed differential line drivers used in the IC, is disclosed. In a high speed line driver the load resistors of the driver are connected to a power supply, either the local power supply or the receiver power supply. DC power for the driver is supplied through these resistors. A large portion of this power, supplied from the power supply is wasted in the DC set-up circuit of the differential line driver. It is proposed to use this wasted power to power selected circuits of an IC. The use of this wasted power from the drivers for powering the circuits reduces the overall power dissipation of the system.

Claims

1. A power recovery circuit for recovering the wasted power supplied to a differential driver pair in a system through resistor loads connected to a system supply, comprising:

a biasing control circuit having a current sensing and control element coupled to sources of the differential driver pair to bias the sources of the differential driver pair;

a start up circuit coupled to the resistor loads of the differential driver pair, the start up circuit enabled to provide an initial starting bias voltage and current to the biasing control circuit when the driver power supply is enabled; and

,

a voltage regulator coupled to an output of the biasing control circuit to regulate the output supply voltage to electronic circuits;

the power recovery circuit configured for recovering wasted power from the power supplied to the differential driver pair, in the form of current and voltage available at the connected source of the differential driver pair to provide regulated power to electronic circuits.

2. The power recovery circuit of claim 1, wherein said power recovery circuit is implemented in one of:

an integrated circuit (IC), a system on chip (SOC), a chip on board (COB).

3. The power recovery circuit of claim 2, wherein said electronic circuits are at least a portion of the circuits of one of an:

IC, SOC, COB.

4. The power recovery circuit of claim 1, further comprising:

a voltage booster enabled to step up an input voltage of said voltage regulator.

5. The power recovery circuit of claim 1, wherein the voltage booster is coupled between the biasing control circuit and the voltage regulator to provide a stepped up voltage to the voltage regulator.

6. The power recovery circuit of claim 1, wherein the driver load resistors are terminated to a remote power supply.

7. The power recovery circuit of claim 6, wherein said remote power supply is part of a remote receiver.

8. The power recovery circuit of claim 1, wherein the driver load resistors are terminated on one of said:

IC, SOC, COB.

9. The power recovery circuit of claim 1, wherein the current sensing and control element is a voltage controlled current source.

10. The power recovery circuit of claim 7, wherein said voltage controlled current sources are selected from a group of elements consisting of:

MOSFET devices, BJT devices.

11. The power recovery circuit of claim 1, wherein said start up circuit bleeds a small amount of power from the power supply to start said biasing control circuit.

12. The power recovery circuit of claim 1, wherein the said start up circuit is disabled from the biasing control circuit once the bias conditions are reached.

13. A method for powering a part of an electronic circuit from at least a portion of wasted power recovered from differential drivers, the method comprising:

recovering the wasted power;

regulating the recovered power; and

,

supplying the regulated power as voltage and current output to power at least part of the electronic circuit.

14. The method of claim 13, wherein the electronic circuit is a portion of one of:

an integrated circuit (IC), a system on chip (SOC), a chip on board (COB).

15. The method of claim 14, wherein the use of the recovered power reduces the power consumption of said one of:

IC, SOC, COB.

16. The method of claim 13, wherein said recovering the wasted power comprises:

recovering the power supplied through resistor loads connected to a supply voltage.

17. The method of claim 13, wherein said regulating of the recovered power further comprises:

boosting the voltage to a usable voltage by means of a voltage booster.

18. The method of claim 13, wherein the use of the recovered power reduces the total power dissipation of the system.

19. A power recovery and supply method for recovering and using wasted power from DC coupled output drivers of a TMDS comprising:

recovering the wasted power of the DC coupled output drivers using a power recovery circuit;

regulating the recovered power using a voltage regulator; and

,

supplying the regulated power as voltage and current outputs to power at least a portion of the circuits of the system.

20. The method of claim 19, wherein the method is implemented in one of:

an integrated circuit (IC), a system on chip (SOC), a chip on board (COB).

21. The method of claim 19, wherein the DC coupled output drivers are part of a TMDS that is a HDMI transmitter system.

22. The method of claim 19, wherein the DC coupled output drivers are part of a TMDS that is a DVI transmitter system.