Analog Devices,inc.

Analog Devices Global

Sean T Morley

Brian Keith Russell

Provided herein are amplifiers, such as buffers, with increased headroom. An amplifier stage includes a follower transistor and current source configured to receive a power supply voltage comprising an alternating current component and a direct current component. The alternating current component of the power supply voltage has substantially the same frequency and magnitude as the input signal received by the follower transistor. In radio frequency (RF) and intermediate frequency (IF) buffer applications, for example, the increased headroom can allow for linear buffering of an input signals with increased amplitude so that the output power one decibel (OP1dB) compression point can be increased.

Buffer with increased headroom

Driver circuitry is described. The circuitry is specifically adapted for use in transmission line environments and provides an offset and swing voltage at an output thereof. The voltages provided at the output are both provided by a current source provided within the driver circuit and coupled to a differential pair current switch.

Low power driver circuitry

A method and circuit for measuring the optical modulation amplitude in the operating region of a laser diode is described. The method utilises two measurements of OMA, each measurement being related to the slope in a specific portion of the operating region of the power/current characteristic curve of the laser diode. By combining the two measurement values, the invention provides a 1 measurement for OMA in the operating region of the laser diode that allows for the presence of a non-linear response in the region.

Method and circuit for measuring the optical modulation amplitude (OMA) in the operating region of a laser diode

A circuit comprises a current source providing an input current, first and second transistors having common control terminals and forming a current mirror connected between first and second power supply potentials, with the first transistor having an input coupled to the current source, the current mirror generating a mirror current at an output of the second transistor, and an amplifier connected in a negative feedback loop around the first transistor, wherein the amplifier input is referenced to the first power supply potential, and the amplifier output is referenced to the second power supply potential. A method for improving power supply rejection ratio of a current mirror is also described.

Current mirror having improved power supply rejection

A data transmission system wherein a datastream of digital words is processed in two parallel pipelined datapaths with the logical operations being performed at a clock rate which is a fraction of some other clock rate identified as a main clock rate. The outputs of the datapath logic are directed respectively to T-latch storage registers the outputs of which are directed at the fractional clock rate to corresponding inputs of a multiplexer serving to combine the two datastreams into a single datastream at the main clock rate. The multiplexer is clocked in synchronism with the T-latch clocks in timed sequence to prevent the development of a transparent path between either T-latch input and the multiplexer output.

Reduced transistor-count data storage and multiplexing system

Signal-sampling apparatus wherein information signals are directed to a register under the control of first clock pulses and are latched into the register under the control of second clock pulses. A calibrator monitors the timing of the first and second clock pulses to determine if they are so close together that data signals subsequently output from the register will be distorted so as to cause errors in downstream devices. If such condition is found, the calibrator inverts the phase of the second clock pulses to assure proper time spacing to avoid data corruption.

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Limerick, Ireland

Sean T Morley