IP Library Granted Patent US 8,866,552
Granted Patent B2
US 8,866,552 · App. 13/721,786 · Granted Oct 21, 2014

Current-mode line driver

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 8,866,552
App. No.
13/721,786
Granted
Oct 21, 2014
Kind
B2
Abstract

Disclosed are various embodiments of a current-mode line driver that may facilitate transmitting signals to a load. The current-mode line driver may comprise a common-mode current sense element that provides a signal corresponding to the common-mode output current of the line driver. A transconductance element receives the signal from the common-mode current sense element and provides a compensating current that is based at least in part on the signal. The compensating current may reduce the common-mode output current of the line driver.

Claims (47)

1. A line driver comprising:

a common-mode current sense element connected to an output for the line driver, the common-mode current sense element configured to provide a signal corresponding to a common-mode output current for the line driver;

a transconductance element configured to receive the signal from the common-mode current sense element and to provide a compensating current based at least in part on the signal; and

a capacitance coupled to a transconductance element output and a ground for the line driver.

2. The line driver of claim 1 , wherein the common-mode current sense element comprises a first resistor coupled in series to a second resistor.

3. The line driver of claim 1 , wherein the transconductance element comprises a transconductance amplifier.

4. The line driver of claim 1 , further comprising:

a voltage buffer comprising a voltage buffer input and a voltage buffer output, the voltage buffer output being connected to a transconductance element output.

5. A line driver comprising:

a common-mode current sense element connected to an output for the line driver, the common-mode current sense element configured to provide a signal corresponding to a common-mode output current for the line driver;

a transconductance element configured to receive the signal from the common-mode current sense element and to provide a compensating current based at least in part on the signal;

a resistance coupled to a transconductance element output, the resistance comprising a resistance tap;

a first voltage buffer configured to receive a first input signal for the line driver, the first voltage buffer comprising a first voltage buffer output that is connected to the resistance tap; and

a second voltage buffer configured to receive a second input signal for the line driver, the second voltage buffer comprising a second voltage buffer output connected to the resistance tap.

6. The line driver of claim 5 , further comprising:

a first current mirror slave comprising a first current mirror slave input and a first current mirror slave output, the first current mirror slave input being connected to the first voltage buffer, the first current mirror slave output being connected to the common-mode current sense element; and

a second current mirror slave comprising a second current mirror slave input and a second current mirror slave output, the second current mirror slave input being connected to the second voltage buffer, the second current mirror slave output being connected to the common-mode current sense element.

7. A line driver comprising:

a common-mode current sense element connected to an output for the line driver, the common-mode current sense element configured to provide a signal corresponding to a common-mode output current for the line driver;

a transconductance element configured to receive the signal from the common-mode current sense element and to provide a compensating current based at least in part on the signal; and

a plurality of capacitances connected to an output of the transconductance element and with a plurality of inputs for a plurality of current mirror slaves.

8. A method, comprising:

obtaining a differential-mode input voltage for a line driver;

providing a differential-mode output current for the line driver based at least in part on the differential-mode input voltage;

providing a compensating current corresponding to a common-mode output current to a tap associated with resistance; and

reducing the common-mode output current based on the compensating current.

9. The method of claim 8 , further comprising providing a voltage corresponding to the common-mode output current to a transconductance element; and

wherein providing the compensating current further comprises providing the compensating current using the transconductance element and based at least in part on the voltage.

10. The method of claim 9 , further comprising utilizing a common-mode Miller effect using a plurality of capacitances coupled to the transconductance element that provides the compensating current.

11. The method of claim 8 , further comprising:

providing an output signal of a voltage buffer to a resistance; and

reducing a common-mode component of the output signal of the voltage buffer based on the compensating current.

12. The method of claim 8 , further comprising providing a signal corresponding to the common-mode output current using a common-mode current sense element.

13. An apparatus comprising circuitry configured to:

provide a signal corresponding to a common-mode output current for a line driver;

provide a compensating current to a tap associated with resistance based at least in part on the signal; and

reduce the common-mode output current based on the compensating current.

14. The apparatus of claim 13 , wherein the circuitry is further configured to:

provide an output signal of a voltage buffer to the resistance; and

reduce a common-mode component of the output signal of the voltage buffer based on the compensating current.

15. The apparatus of claim 13 , wherein the circuitry is further configured to:

buffer a first differential input signal for the line driver; and

buffer a second differential input signal for the line driver.

16. The apparatus of claim 13 , wherein the circuitry is further configured to provide a voltage corresponding to the common-mode output current to a transconductance element; and

wherein providing the compensating current further comprises providing the compensating current using the transconductance element and based at least in part on the voltage.

17. The apparatus of claim 16 , wherein the circuitry is further configured to utilize a common-mode Miller effect using a plurality of capacitances coupled to the transconductance element that provides the compensating current.

18. The apparatus of claim 13 , wherein the circuitry is further configured to provide a signal corresponding to the common-mode output current using a common-mode current sense element.

Assignments (7)
CORRECTIVE ASSIGNMENT TO CORRECT THE PATENT NUMBER 9,385,856 TO 9,385,756 PREVIOUSLY RECORDED AT REEL: 47349 FRAME: 001. ASSIGNOR(S) HEREBY CONFIRMS THE MERGER. Recorded Mar 22, 2019
From: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
To: AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED
Reel/Frame 051144/0648 →
CORRECTIVE ASSIGNMENT TO CORRECT THE EFFECTIVE DATE PREVIOUSLY RECORDED ON REEL 047229 FRAME 0408. ASSIGNOR(S) HEREBY CONFIRMS THE THE EFFECTIVE DATE IS 09/05/2018. Recorded Oct 29, 2018
From: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
To: AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED
Reel/Frame 047349/0001 →
MERGER Recorded Oct 4, 2018
From: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
To: AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED
Reel/Frame 047229/0408 →
TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENTS Recorded Feb 3, 2017
From: BANK OF AMERICA, N.A., AS COLLATERAL AGENT
To: BROADCOM CORPORATION
Reel/Frame 041712/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 1, 2017
From: BROADCOM CORPORATION
To: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
Reel/Frame 041706/0001 →
PATENT SECURITY AGREEMENT Recorded Feb 11, 2016
From: BROADCOM CORPORATION
To: BANK OF AMERICA, N.A., AS COLLATERAL AGENT
Reel/Frame 037806/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 28, 2013
From: PAN, HUI; YAO, YUAN; HAMMAD, MOSTAFA; ABDELHALIM, KARIM VINCENT; TAN, JUNHUA; FUJIMORI, ICHIRO
To: BROADCOM CORPORATION
Reel/Frame 029704/0989 →