Inphi Corporation

Broadcom Corporation

Sitrus Technology Corporation

Karim Vincent Abdelhalim

Michael Q Le

Halil Cirit

Jorge Pernillo

Hui Pan

Yuan Yao

Haidang Lin

Junhua Tan

Lawrence Tse

Karthik S Gopalakrishnan

Ichiro Fujimori

Mostafa Mohammad Hany Ali Hammad

Mostafa Hammad

An H-bridge integrated laser driver optimizes power dissipation, impedance matching, low-swing and high-swing reliability for electro-absorption modulated laser (EML) and directly modulated laser diode (DML) applications. The laser driver includes a retimer for converting low-speed parallel data to a high-speed serial bit stream and to an inverted representation of the high-speed parallel bit stream, an M-bit PMOS DAC configured to receive a first buffered bit stream, an N-bit NMOS DAC configured to receive a second buffered bit stream substantially synchronized with the first buffered bit stream. A protective device is coupled between the M-bit DAC and the N-bit DAC. A first DC level-shifting predriver array is coupled between the retimer and the M-bit DAC to receive the high-speed parallel bit stream and the inverted high-speed parallel bit stream, and a second DC level-shifting predriver array is coupled between the retimer and the N-bit DAC to receive the high-speed parallel bit stream and the inverted high-speed parallel bit stream. An impedance matching module is coupled to an output of the protective device. The laser driver may be integrated on a CMOS communication chip.

H-bridge integrated laser driver

A DC-shifting predriver has an input port configured for coupling to a serial data stream, an inverting output amplifier having an feedback node and an output port configured for coupling to a transistor at the input to a high-speed DAC or TX driver, and a capacitor AC-coupled between the input port and the feedback node. A weak feedback inverter having structure similar to, but less drive strength than the inverting output amplifier is coupled between the output port and the feedback node to act as a positive feedback latch. The predriver provides a DC shift up to 3V with high reliability and minimal intersymbol interference for data rates from 10 GS/s to 28 GS/s or higher. The predriver may provide multiple input ports implemented as a predriver array in an M-bit system, and the output amplifier may consist of N stages.

High-speed DC shifting predrivers with low ISI

The present invention relates to telecommunication techniques and integrated circuit (IC) devices. In a specific embodiment, the present invention provides a laser deriver apparatus that includes a main DAC section and a mini DAC section. The main DAC section processes input signal received from a pre-driver array and generates an intermediate output signal. The mini DAC section provides a compensation signal to reduce distortion of the intermediate output signal. The intermediate output signal is coupled to output terminals through a cascode section and/or a T-coil section. There are other embodiments as well.

CMOS externally modulated laser driver

The present invention relates to data communication techniques and integrated circuit devices. More specifically, embodiments of the present invention provide an input buffer module that utilizes one or more equalization elements. The input buffer module includes an array of inverters arranged in a series. An equalization element is configured in series relative to a segment of the array of inverters. The resistance value of the equalization element is predetermined based on a delay associated with the segment of the array of inverters. There are other embodiments as well.

Equalization for transmitter input buffer array

Non-ideal downstream loading of a differential driver in a single ended circuit driving a communications laser&#x2014;e.g., Electro absorption Modulated Laser (EML)&#x2014;may be compensated by deploying a second matching network at the non-functional (terminated) driver output node. Certain embodiments may further compensate for distortion arising from circuit non-ideality, by introducing a laser replica downstream of the second matching network to mimic electrical properties of the laser. Embodiments may sufficiently compensate for downstream circuit non-ideality to allow replacing the bulky choke inductor of a bias tee, with a resistor. Substituting a resistor for a more complex inductor structure can simplify design and fabrication of the single-ended driver circuit, and also reduce footprint by eliminating area formerly occupied by the choke inductor. Embodiments may be particularly suited to bridge integration with other system components undergoing design migration toward double-ended modulator circuit architectures featuring a differential driver.

Configurable laser modulator driver and output matching network

Systems, apparatuses, and methods are provided for analog-to-digital converters (ADCs), such as successive-approximation-register (SAR) ADCs and pipelined ADCs that utilize distributed virtual-ground switching (DVS). DVS circuits and systems receive reference signal inputs that are provided to input signal buffers at the input side of the buffers via reference switches. The input signal buffers and corresponding switches are distributed into scaled replicas that each receive an analog input signal via input signal switches during a first operational phase and are connected to top plates of corresponding distributed capacitors. The bottom plates of the capacitors are sampled to provide analog input signal representations. Based on the value of the signal representations, a state machine controls each of the switches to apply reference signals to the input buffers, during a second operation phase, and to iteratively generate additional signal representations and provide a digital signal that corresponds to the analog input signal.

Distributed virtual-ground switching for SAR and pipelined ADC

An output stage of a differential line driver generates a differential output signal. A common-mode component of the differential output signal is decoupled from the differential output signal using a common-mode voltage sense. The common-mode component of the differential output signal is provided to a capacitor that is coupled between the output stage and the common-mode voltage sense.

Class AB differential line drivers

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.

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Newport Coast, CA, United States of America

Karim Vincent Abdelhalim