Optoelectronic transmitter with improved control circuit and laser fault ...

[54] OPTOELECTRONIC TRANSMITTER WITH IMPROVED CONTROL CIRCUIT AND LASER FAULT LATCHING

[75] Inventors: Patrick B. Gilliland; Evgueniy Anguelov, both of Chicago, 111.

[73] Assignee: Stratos Lightwave, Inc., Chicago, 111.

[21] Appl. No.: 08/904,130 [22] Filed: Aug. 9, 1997

[51] Int. CI.7 H04B 10/00; H04B 10/04

[52] U.S. CI 359/110; 359/152; 359/153;

359/163; 359/187

[58] Field of Search 359/152, 163,

359/187, 154, 145; 385/14; 257/81, 83,

84

[56] References Cited

U.S. PATENT DOCUMENTS

4,208,621 6/1980 Hipkins et al 318/138

5,402,433 3/1995 Stiscia 372/31

5,479,288 12/1995 Ishizuka et al 359/163

5,535,034 7/1996 Taniguchi 359/152

5,561,727 10/1996 Akita et al 385/88

5,714,746 2/1998 Dvorkis et al 235/472

5,999,294 12/1999 Petsko 359/145

Primary Examiner—Leslie Pascal
Assistant Examiner—Dalzid Singh

Attorney, Agent, or Firm—David L. Newman; Steven M.
Evans

[57] ABSTRACT

An optoelectronic transmitter is provided including a semiconductor laser as the active optical transmitting element. The transmitter includes first and second printed circuit boards, with the first printed circuit board having mounted thereon electronic components and circuitry for driving the optoelectronic transmitter. A transmitting optical subassembly (TOSA) is mounted to the second printed circuit board. The second printed circuit board has an array of solder pads disposed on the back surface thereof, and the first printed circuit board has a corresponding array of solder pads disposed along an outer edge of the board. Spacing of the solder pads is such that when the first printed circuit board is placed in perpendicular abutment against the outer edge of the first printed circuit board, the solder pads formed on the first printed circuit board are aligned adjacent to the solder pads disposed on the back of the second printed circuit board. Solder joints are then formed in the angular space between the solder pads disposed on the first and second printed circuit boards, bonding the boards together while simultaneously providing electrical connections between the various components mounted on the individual printed circuit boards. An improved control circuit for driving the semiconductor laser transmitter facilitates this arrangement. The improved control circuit provides both automatic power control and laser slope compensation in order to normalize the output characteristics of individual transceivers. An alternate embodiment further includes a laser fault latching circuit for disabling the laser transmitter, and providing laser fault indication.

34 Claims, 6 Drawing Sheets