IP Library Granted Patent US 8,149,026
Granted Patent B2
US 8,149,026 · App. 12/826,317 · Granted Apr 3, 2012

Driver circuit and adjustment method therefor

Assignee: Fujitsu Semiconductor Limited
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Quick Facts
Patent No.
US 8,149,026
App. No.
12/826,317
Granted
Apr 3, 2012
Kind
B2
Abstract

A driver circuit includes an output section; a voltage-dividing section configured to divide a first voltage at a coupling point between the output section and a termination resistor; a comparison section configured to compare a voltage difference with one of the first voltage and a second voltage, the voltage difference being a difference between the second voltage at a coupling point between the termination resistor and a transmission path and a third voltage output from the voltage-dividing section; and an adjustment section configured to adjust a voltage division ratio of the voltage-dividing section on the basis of the comparison result obtained in the comparison section.

Claims (30)

1. A driver circuit comprising:

an output section;

a voltage-dividing section configured to divide a first voltage at a coupling point between the output section and a termination resistor;

a comparison section configured to compare a voltage difference with one of the first voltage and a second voltage, the voltage difference being a difference between the second voltage at a coupling point between the termination resistor and a transmission path and a third voltage output from the voltage-dividing section; and

an adjustment section configured to adjust a voltage division ratio of the voltage-dividing section on the basis of the comparison result obtained in the comparison section.

2. The driver circuit according to claim 1 , wherein

the comparison section compares the polarity of the voltage difference with one of the polarities of the first voltage and the second voltage.

3. The driver circuit according to claim 2 , wherein

the adjustment section adjusts the voltage division ratio so that a difference between the voltage difference and one of the first voltage and the second voltage decreases.

4. The driver circuit according to claim 1 , wherein

the adjustment section reduces a variation width of the voltage division ratio as the number of times the adjustment is performed increases.

5. The driver circuit according to claim 1 , further comprising:

a rectification section configured to rectify the first voltage; and

a termination resistance adjustment section configured to adjust the resistance value of the termination resistor in response to a rectification result obtained in the rectification section.

6. The driver circuit according to claim 5 , wherein

the termination resistance adjustment section reduces a variation width of the resistance value of the termination resistor as the number of times the adjustment is performed increases.

7. An adjustment method for a driver circuit, comprising:

comparing a voltage difference with one of a first voltage and a second voltage, the voltage difference being a difference between a third voltage, obtained by dividing the first voltage at a coupling point between an output section and a termination resistor, and the second voltage obtained at a coupling point between the termination resistor and a transmission path; and

adjusting a voltage division ratio used for generating the third voltage, on the basis of the comparison result.

8. The adjustment method for the driver circuit according to claim 7 wherein

the comparing includes comparing the polarity of the voltage difference with one of the polarities of the first voltage and the second voltage.

9. The adjustment method for the driver circuit according to claim 7 wherein

the voltage division ratio is adjusted so that a difference between the voltage difference and one of the first voltage and the second voltage decreases.

10. The adjustment method for the driver circuit according to claim 7 , wherein

the voltage division ratio is adjusted so that a variation width of the voltage-dividing ratio is reduced as the number of times the adjustment is performed increases.

11. The adjustment method for the driver circuit according to claim 7 , wherein

in the comparing, the first voltage is rectified; and

the resistance value of the termination resistor is adjusted on the basis of the rectification result.

12. The adjustment method for the driver circuit according to claim 11 , wherein

the resistance value of the termination resistor is adjusted so that a variation width of the resistance value of the termination resistor is reduced as the number of times the adjustment is performed increases.

Assignments (8)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 16, 2025
From: MONTEREY RESEARCH LLC
To: SOUTHFORK IP HOLDINGS LLC
Reel/Frame 071299/0161 →
CORRECTIVE ASSIGNMENT TO CORRECT THE 8647899 PREVIOUSLY RECORDED ON REEL 035240 FRAME 0429. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY INTERST. Recorded Nov 3, 2020
From: CYPRESS SEMICONDUCTOR CORPORATION; SPANSION LLC
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 058002/0470 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 14, 2016
From: CYPRESS SEMICONDUCTOR CORPORATION
To: MONTEREY RESEARCH, LLC
Reel/Frame 040911/0238 →
PARTIAL RELEASE OF SECURITY INTEREST IN PATENTS Recorded Aug 11, 2016
From: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
To: CYPRESS SEMICONDUCTOR CORPORATION; SPANSION LLC
Reel/Frame 039708/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 2, 2015
From: SPANSION, LLC
To: CYPRESS SEMICONDUCTOR CORPORATION
Reel/Frame 036051/0001 →
SECURITY INTEREST Recorded Mar 21, 2015
From: CYPRESS SEMICONDUCTOR CORPORATION; SPANSION LLC
To: MORGAN STANLEY SENIOR FUNDING, INC.
Reel/Frame 035240/0429 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 11, 2013
From: FUJITSU SEMICONDUCTOR LIMITED
To: SPANSION LLC
Reel/Frame 031205/0461 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 1, 2010
From: INAGAKI, YASUKUNI; MASHIMO, AKIRA
To: FUJITSU SEMICONDUCTOR LIMITED
Reel/Frame 024625/0355 →
Priority Claims (1)
JP 2009-162024 · Jul 8, 2009 · national
Continuity (1)
Related Publication 20110006812A1 · Jan 13, 2011