Abstract: Light emitting elements with preselected or adjustable impedance characteristics are provided. Embodiments using a preselected impedance characteristic obtain significant performance benefits compared to the prior art. Embodiments having an adjustable impedance may alter the impedance associated with the light emitting component such that it has a substantially constant resistive or reactive impedance that improves certain performance attributes. This solution virtually eliminates the need for external compensation components and relieves the burden of impedance matching and circuit specialization from the driver circuit.

Abstract: Circuits and methods for automatically controlling lightwave emitters are provided. A control system is provided that includes a variable gain circuit for automatically adjusting the gain of a control signal with respect to a feedback signal, a modulation signal, and a reference signal. This allows the optical output of the lightwave emitter to remain substantially constant despite changes in transfer ratio due to aging or temperature variations. Furthermore, in some embodiments, a user may select the overall gain of the system to optimize response time, bandwidth, or steady-state accuracy.

Abstract: Circuitry and methods for improved amplifiers with large bandwidth and constant gain are provided. The combination of a synthetic inductive drain load and a bridged-T matching network provide amplifiers that can drive a substantial capacitive load with the above mentioned improvements over prior amplifiers. Additionally, circuits presented allow for improved rise time and insensitivity to temperature variations.

Abstract: Circuitry and methods for obtaining accurate measurements of current supplied by an integrated circuit are provided. Current calculations are performed using information from a precision termination resistor and from the ratio relationship of two on-chip resistors. The invention provides a way to obtain accurate current measurements without the use of component trimming.

Abstract: Synthetic circuit elements and amplifier applications for synthetic circuit elements are provided. The synthetic circuit elements disclosed herein may be configured to compensate for some or all of the parasitic capacitance normally associated with circuit elements disposed on a substrate providing a selectable impedance characteristic. Amplifier circuit constructed using such synthetic circuit elements exhibit improved performance characteristics such as improved recovery time, frequency response, and time domain response.

Abstract: Light emitting elements with preselected or adjustable impedance characteristics are provided. Embodiments using a preselected impedance characteristic obtain significant performance benefits compared to the prior art. Embodiments having an adjustable impedance may alter the impedance associated with the light emitting component such that it has a substantially constant resistive or reactive impedance that improves certain performance attributes. This solution virtually eliminates the need for external compensation components and relieves the burden of impedance matching and circuit specialization from the driver circuit.

Abstract: Circuitry and methods for improved amplifiers with large bandwidth and constant gain-are provided. The combination of a synthetic inductive drain load and a bridged-T matching network provide amplifiers that can drive a substantial capacitive load with the above mentioned improvements over prior amplifiers. Additionally, circuits presented allow for improved rise time and insensitivity to temperature variations.

Abstract: Driver circuitry with a tuned output impedance is provided. Tuning is provided by an isolation circuit and matching network coupled to an output of the driver circuit. The isolation circuit isolates the capacitance associated portions of the driver circuit thereby reducing overall output capacitance. The matching network substantially compensates for reactive impedances associated with other portions of the driver circuit. These tuning circuits allow the driver circuit overcome intrinsic reactance and exhibit a substantially resistive output impedance characteristic.

Abstract: A test probe includes a probe tip electrically connected to a probe amplifier. The probe tip includes an input conductor, a shield conductor, and a middle conductor between the input conductor and the shield. The capacitance between the middle conductor and the input conductor are employed in a frequency compensation circuit. In one embodiment the three conductors form a triaxial probe tip. The middle conductor is a thin film formed along an equipotential surface defined between the input conductor and the shield with the middle conductor not present.

Abstract: The precision programmable attenuator of the present invention makes use of a pair of non-interactive parallel connected divider circuits to provide a flat frequency response over a wide bandwidth. A first of these divider circuits is a low frequency divider circuit which provides a predetermined attenuation of low frequency signals. The second high frequency divider attenuates the high frequency signals and does not interact with the low frequency attenuator. Therefore, each of these dividers can be separately tuned independent of the other. The implementation of the low frequency divider is a resistive divider network which provides a DC coupling of the input signal to the output. The high frequency divider is comprised of an adjustable capacitor divider network which is automatically electronically tuned to obtain the desired high frequency gain response.