Abstract: In a typical DC-DC converter, an error amplifier is used to sense and amplify the difference between the feedback voltage and the reference voltage. In the event of current overloading (limit condition), example embodiments of the disclosed systems and methods of over-load protection with voltage fold-back fold back the reference voltage proportional to the current limit. The regulator may continue to regulate in this fold-back voltage reference condition without shutting down the converter, saturating the inductor, or causing a catastrophic failure at the power FETs. The disclosed systems and methods of over-load protection with voltage fold-back resolve consecutive switching cycle current build up in high input voltage DC/DC convertor applications due to the latency of current limit circuitry.

Abstract: In a typical DC-DC converter, an error amplifier is used to sense and amplify the difference between the feedback voltage and the reference voltage. In the event of current overloading (limit condition), example embodiments of the disclosed systems and methods of over-load protection with voltage fold-back fold back the reference voltage proportional to the current limit. The regulator may continue to regulate in this fold-back voltage reference condition without shutting down the converter, saturating the inductor, or causing a catastrophic failure at the power FETs. The disclosed systems and methods of over-load protection with voltage fold-back resolve consecutive switching cycle current build up in high input voltage DC/DC convertor applications due to the latency of current limit circuitry.

Abstract: A switched capacitor measurement circuit is provided for measuring the capacitance of an input capacitor with a parallel parasitic resistor. The circuit comprises a switching arrangement, a reference capacitor, a steered current sink and an operational amplifier with an output, a non-inverting input connected to a reference voltage source and an inverting input connected to a first terminal of the input capacitor. The current sink is steered to compensate for a charge current due to the parasitic resistor. Still further, the circuit comprises a digital adder and an analog-to-digital converter with an analog input connected to the output of the operational amplifier and a digital output connected to a first input of the digital adder.

Abstract: A switched capacitor measurement circuit is provided for measuring the capacitance of an input capacitor with a parallel parasitic resistor. The circuit comprises a switching arrangement, a reference capacitor, a steered current sink and an operational amplifier with an output, a non-inverting input connected to a reference voltage source and an inverting input connected to a first terminal of the input capacitor. The current sink is steered to compensate for a charge current due to the parasitic resistor. Still further, the circuit comprises a digital adder and an analog-to-digital converter with an analog input connected to the output of the operational amplifier and a digital output connected to a first input of the digital adder.

Abstract: A fiber optic cleaning device having a hollow or tubular body containing a frangible ampoule cleaning fluid. Upon rupturing the ampoule, the cleaning fluid is released to a porous applicator couple to one end of the hollow body. The porous applicator is then applied to a fiber optic contact area for removing contaminants, such as dust.

Abstract: The present invention describes a process for bonding a semiconductor die to a selected substrate, including the formation of a die positioning structure on the substrate to receive and secure the semiconductor die. The substrate is selected from a number of materials, the properties of which render it penetrable by electron beam radiation. The die positioning structure is a second material which is electron beam curable, and which is deposited and cured at high speed on the substrate in a novel fashion in accordance with the present invention in a highly efficient reproducible and economical manner.

Abstract: The present invention relates to a device to assist in filling a hole in a sheet or plate of any material, with a filler compatible with the material, the device comprising a flexible plate adapted to be inserted through the hole in the sheet or plate; a detachable attachment member adapted to extend generally perpendicularly from a surface of the flexible plate and including a connection to locate at least one locking member thereto; the locking member being detachably attachable to the attachment member so as to apply a tensile load on the attachment member thereby causing the flexible plate to bear on and be held adjacent to the hole.