Rise time

About: Rise time is a research topic. Over the lifetime, 4748 publications have been published within this topic receiving 47512 citations.

Method and apparatus for control of current rise time during multiple fuel injection events

Abstract: The present invention relates to a method and apparatus for control of current rise time during multiple fuel injection events. The invention utilizes a single boost voltage supply circuit, in which the boost capacitor is designed to store slightly more than twice the total energy required to pull-in a single fuel injector solenoid during the prescribed time. A reference waveform simulating the desired current rise time is compared to the actual boost voltage produced by the circuit. The boost voltage is modulated (switched on and off) in order to maintain the boost voltage within a predetermined window around the reference waveform. This modulation will compensate for any droop in boost voltage at the time of actuation, and will also compensate for two solenoids being actuated at the exact same time. It is only necessary that a nninimum amount of energy be stored in the boost capacitor at the completion of an actuation event, and the level of this minimum amount of energy can easily be determined by analysis or experimentation. Additionally, it is very easy to modify the shape and duration of the reference waveform, thus allowing for a very flexible solenoid drive circuit whose pull-in time and boost energy consumption can be easily changed to meet the requirements of an application without modifying the LRC time constants of the system.

High gain-bandwidth differential distributed InP D-HBT driver amplifiers with large (11.3 V/sub pp/) output swing at 40 Gb/s

Abstract: High-performance and compact 40-Gb/s driver amplifiers were realized in 1.2-/spl mu/m emitter double-heterojunction InGaAs-InP HBT (D-HBT) technology with a maximum cut-off frequency (f/sub T/) of 150 GHz and a maximum oscillation frequency (f/sub max/) of 200 GHz. Two-stage differential drivers feature a lumped input and fully distributed output stage and deliver a maximum differential output swing of 11.3 V peak-to-peak (V/sub pp/) at 40 Gb/s with less then 350 fs of added rms jitter and rise and fall times of about 7 ps while consuming a total power of 3 W. When biased at a lower output swing of 6.3 V/sub pp/, excellent 40-Gb/s eyes with a 7-ps fall time, 6-ps rise time, and no observable jitter deterioration compared with the input source are obtained at a reduced power consumption of 1.7 W. On-wafer measured differential S-parameters show a differential gain of 25 dB, 50 GHz bandwidth, and input and output reflection below -20 dB from 2 to 45 GHz. The amplifiers' small die size (1.0/spl times/1.7 mm), relatively low power consumption, large output swing, and ability to have dc coupled inputs and outputs enable compact 40-Gb/s optical transmitters with good eye opening for both conventional transmission formats such as nonreturn-to-zero and return-to-zero and alternative formats such as duobinary and differential phase shift keying.

Pulse switching for high energy lasers

Abstract: A saturable inductor switch for compressing the width and sharpening the rise time of high voltage pulses from a relatively slow rise time, high voltage generator to an electric discharge gas laser (EDGL). The switch also provides a capability for efficient energy transfer from a high impedance primary source to an intermediate low impedance laser discharge network. More specifically, a saturable inductor switch is positioned with respect to a capacitive storage device, such as a coaxial cable, so that when a charge build-up in the storage device reaches a predetermined level, saturation of the switch inductor releases or switches energy stored in the capacitive storage device to the EDGL. Also disclosed are cascaded saturable inductor switches for providing output pulses having rise times of less than ten nanoseconds as required for efficient excitation of EDGL's, the pulse rise time being determined by the thickness of a high permeability material forming the saturable inductor switch. In addition, a technique for magnetically biasing the saturable inductor switch is disclosed so that only pulses from a pulse generator having one polarity are passed and pulses having the other polarity are blocked, thereby improving the lifetime of electrical components that are sensitive to voltage reversals.

Optimized Charge Pump With Clock Booster for Reduced Rise Time or Silicon Area

Abstract: In this brief an improved Dickson charge pump (DCP) topology exploiting a clock boosting is presented. An accurate while simple theoretical model for the dynamic behavior of the charge pump is carried out. Analytical comparison with the traditional DCP reveals that the proposed solution can achieve a rise time or area reduction between 10% and 60% at the cost of a slight circuit complexity. Finally, simulation results using a 65-nm CMOS technology show the accuracy of the analytical model as well as the advantages of the proposed solution.