Burr-brown Research Corporation

Burr-brown Corporation

Neil P Albaugh

Robert M Stitt, Ii

Gordon R Kane

In a circuit including a differential amplifier, a switching device is coupled to the input terminals of the differential amplifier for periodically applying signals thereto. A second switching device is coupled to the output terminals of the differential amplifier and is synchronized with the switching device coupled to the input terminal. By providing an output signal that is constructed from signals amplified in an inverted and non-inverted mode of the differential amplifier, sources of noise and drift-related errors can be minimized.

Apparatus and method for noise reduction in a linear amplifier

Means and method is disclosed for achieving a low profile optical coupling to a module comprising an optoelectronic device together with other circuitry. Maintaining the optoelectronic device parallel to the substrate on which it and the associated circuitry are mounted enables the use of standard, well known manufacturing assembly techniques while providing electrical connection to the electric ports of said optoelectronic device. Subsequent to the electrical interconnection operation, the optoelectronic device is moved, together with its connections, to a position substantially orthogonal with the mounting substrate. Optical fiber, light coupling is utilized. The low profile of the overall module package is achieved by introducing the optical fiber in a direction generally parallel with the substrate and perpendicular to the light active surface of the optic port of the optoelectronic device. The structure and method are applicable to both hybrid integrated circuit assembly technology as well as to conventional metallic lead frames for plastic encapsulation.

Low profile optical coupling for an optoelectronic module

Means and method for achieving a low profile optical coupling to a planar mounted optoelectronic device. Maintaining the optoelectronic device planar to the substrate on which it and associated circuitry are mounted enables the use of standard, well known manufacturing assembly techniques while providing electrical connection to the electric ports of said optoelectronic device. Optical fiber, light coupling is utilized. The low profile of the overall package is achieved by introducing the optical fiber on a plane which is generally parallel to the light-active surface of the optic port of said optoelectronic device. Actual optical coupling is achieved by introducing a smooth radius bend in the optical fiber so as to bring the fiber and the light-active surface of the optoelectronic device into generally orthogonal relationship. A glass-to-metal seal is provided where the optic fiber enters the package so as to provide a hermetic seal. Further mechanical and environmental support is provided by encapsulating the assembly, within its package, in an encapsulating medium having an index of refraction essentially matching that of the core of the optical fiber and the optic port of said optoelectronic device so as to reduce the possibility of reflective losses at the juncture of the fiber and said light active surface of said optic port. Efficiency and light handling ability of an optical light fiber are increased by providing a mirror-like interface along its entire length and utilizing both the central core and its cladding as light transmission media.

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Tucson, AZ, United States of America

Neil P Albaugh