Micrel, Incorporated

Advanced Micro Devices Corporation

Fairchild Camera and Instrument Corp.

George W Brown

Thomas S Wong

Bernd Neumann

Phi Thai

Thomas L Reynolds

A noise discriminator circuit and a noise discrimination method in a burst mode receiver is configured to determine the validity of an incoming burst signal by analyzing the timing of the signal edges of incoming signal to look for a time duration conforming to the preamble data bits of a valid burst signal. In one embodiment, the noise discriminator circuit and method analyze the time duration between signal edges of the same pulse of an incoming signal. In another embodiment, the noise discriminator circuit and method analyze the time duration between a first set of pulses of an incoming signal and the time duration between signal edges of a second set of pulses of the incoming signal. When the time durations are within a given time range relating to a predetermined timing separation of a valid burst signal, the incoming signal is validated as a valid burst signal.

Noise discriminator for passive optical network burst mode receiver

Noise discriminator for enhanced noise detection in a passive optical network burst mode receiver

A laser bias control and monitoring circuit receives a monitor diode current on an input node and generate a bias current for a laser diode on an output node where the monitor diode current flows into (positive polarity) or out of (negative polarity) the input node. The laser bias control and monitoring circuit includes a polarity independent current sensing circuit configured to receive the monitor diode current in either positive or negative polarity and to generate a normalized output current having a magnitude proportional to a magnitude of the monitor diode current. In this manner, the laser bias control and monitoring circuit can be used with laser diode and monitor diode combination in either the common anode or the common cathode configuration, or with the monitor diode current being provided from the anode or cathode of the monitor diode. No reprogramming or reconfiguration of the circuit is required.

Polarity independent laser monitor diode current sensing circuit for optical modules

An interface system couples a fixed impedance device to a receiver for transmitting data signals at different data rates at different times. The interface system includes elements that are connected to provide different time constants of responsiveness to data signals of higher and lower data rates without distorting the data signals beyond usability.

AC coupling system for wide band digital data with dynamic AC load

A redundant memory circuit having a memory for storing information in a matrix of interconnected rows and columns, and a row and a column address decoder to access the rows and columns. The memory has a redundant row or rows to replace a defective row or rows in the matrix and a programmable decoder which is programmed with the row address of the defective row to access the redundant row. The row and column address decoders are used to access the defective row and to sequentially access the columns so as to entirely disconnect the defective row from the columns. The programmable decoder is then programmed with the defective row address, bit by bit, in response to the column addresses, to access the redundant row. After this procedure, a verification circuit can be used to verify that the redundant row can be accessed and that the programmable decoder is properly programmed to decode only one address to one row.

Redundant memory circuit and method of programming and verifying the

A sense amplifier and sensing scheme for sensing the normal or blown condition of fuses in a programmable read only memory (PROM) or similar device. A sensing circuit is provided with a threshold level separating high and low input levels indicative of the fuse condition. The sensing circuit has one circuit branch with a first current mirror with a temperature characteristic which provides a threshold level which is slightly divergent with reference to a low level input. Another circuit branch clamps the high input level to the slightly divergent threshold level and uses a second current mirror with a temperature characteristic which provides a high level slightly more divergent than the threshold level. By selecting mirror currents proportionally, high level and threshold level temperature characteristic divergence can be proportionally controlled in selected amounts with respect to the low level. Current sources for the sense amplifier are made to offset voltage fluctuations, making the sense amplifier highly insensitive to voltage fluctuations in addition to temperature variations.

Temperature compensated sense amplifier for PROMs and the like

A circuit and method for providing a desired resistor ratio whereby an output voltage may be derived across one of the members of the ratio pair. A voltage regulator is connected between first and second resistors of the ratio pair to provide voltage compensation partially dependent on third and fourth resistors within the regulator such that the error in each of the resistances of the desired ratio pair is cancelled by matching errors in the third and fourth resistances of the voltage regulator.

Resistor ratio circuit construction

A memory cell is provided which comprises a word line, a current source line, a pair of bit lines, a first transistor having a base terminal, a collector terminal coupled to the word line, a first emitter coupled to a first of the pair of bit lines, a second emitter coupled to the current source line, a second transistor having a base terminal coupled to the collector terminal of the first transistor, a collector terminal coupled to the word line and to the base of the first transistor, a first emitter coupled to a second of the pair of bit lines, and a second emitter coupled to the current source line, and means for directing more current through the second transistor than through the first transistor.

Growing community of inventors

San Jose, CA, United States of America

George W Brown