Abstract: A semiconductor-based optical transceiver. The optical transceiver includes a post-amplifier that may communicate with an optoelectronic transducer, an electro-optic transducer driver that may communicate with an electro-optic transducer, and a control module that controls the operation of the post-amplifier and electro-optic transducer driver. The control module, the post-amplifier, and the electro-optic transducer driver are integrated in a single integrated circuit (IC) that does not require a printed circuit board for interconnecting these components of the optical transceiver.

Abstract: Embodiments of the present invention are directed to a modular optical device with a component insert for sending and/or receiving optical signals. A first fabricated package includes a light source for generating optical signals and/or a light detector for detecting received optical signals. A second fabricated package includes an opening for accepting circuitry. A lead frame mechanically connects the first fabricated package to the second fabricated package and electrically connects the light source and/or the light detector in the first fabricated package to contacts exposed in the opening of the second fabricated package. A component insert is mechanically coupled to the second fabricated package and electrically coupled to the exposed contacts for electrical interoperation with the light source and/or the light detector to transfer optical signals. The modular optical device can be coupled to a substrate configured to be received within a standard host system slot.

Abstract: A feedback system includes an emitter-follower as a gain stage in the forward path. The emitter-follower has a very wide band width and does not, by itself, effectively narrow the bandwidth of an information channel in which it is used. Emitter-followers are frequently used as buffers in many gain systems so using an emitter-follower which is already present effectively reduces die area for the feedback system. In an embodiment, the feedback system includes a differentiator with a programmable zero in the feedback path. The zero in the feedback path creates a pole in the forward path and the programmed location of the zero influences the pole and controls the bandwidth of the forward path. The emitter-follower also buffers the differentiator so that it does not effect the operation of any prior gain stages in which the feedback system is used.

Abstract: A magnetic storage apparatus includes first and second control devices to effectively reduce a disturbance which occurs in a read channel of the apparatus upon transition from a write mode to a read mode. The first control device is in a first gain stage coupled to a read sensor. The second control device is a back-end circuit and, in addition to reducing the duration of the write-to-read disturbance, is effective to significantly reduce offset of the apparatus. A user interface in the form of a serial interface allows user programmability of both of the first and second control devices. The serial interface and the read channel with the first and second control devices are embodied in a pre-amplifier integrated circuit. The programmability affords flexibility to the IC manufacturer as well as to the manufacturer of the magnetic storage device in optimizing the read channel to account for model-to-model and unit-to-unit variations in the write-to-read disturbance.

Abstract: A preamplifier integrated circuit for a magnetic storage device includes read channel and a write channel. The read channel includes a filter in a forward signal path which has a low corner frequency (LCF) which varies in a time dependent manner related to the duration of a write-to-read disturbance induced by a transition from a write mode to a read mode. The LCF of the filter moves from a relatively high initial frequency to a lower steady state frequency to effectively reduce the settling time of the write-to-read disturbance without causing read errors which may arise from overfiltering in the steady state. Favorably, the filter in the forward signal path is formed by a unity gain differential emitter-follower in the forward path and a low pass filter (LPF) in a feedback path around the differential emitter-follower, the pole of the LPF being moved to achieved the movement of the LCF in the forward path.