Pulse-width Converter Research Articles

Discrete simulation of pulse-width converters

The method of modeling pulse-width modulated converters in continuous conducting mode is considered. The result of modeling is a discrete state-space model of converter, with a discretization period equal to switching one. Using of the proposed model can formalize the tasks of object analysis and control system design by using the methods of the up-to-date control theory

A digital coincidence measurement system using FPGA techniques

Abstract A field programmable gate array (FPGA) based digital coincidence system has been developed to use with NaI scintillators for field applications. The analog output signal from the photomultiplier anode is directly transferred into digital signals by pulse height for pulse width conversion. The digital signal contains the energy and timing information of the radiation events. The pulse width is then measured by a vernier type of time-to-digital converter (TDC). The timing information of radiation events is recorded and analyzed by a coincidence unit. Both the TDC unit and the coincidence unit are implemented using a commercial available FPGA board. The measured data is then sent to a personal computer for spectrum display. Efficiency as well as energy calibration has been performed. The system showed a timing resolution about 13 ns and an energy resolution of 12% for 0.511 MeV annihilation gammas; it also successfully demonstrated the background rejection ability through coincidence measurement.

Bit-rate Flexible Picosecond Pulse Width Conversion with All-optical Mono-stable Multivibrator Laser Diode

An optical mono-stable multivibrator laser diode (MM-LD) is realized by using a multi-electrode distributed feedback laser diode. All-optical pulse-width conversion of ultra-short pulses to non-return-to-zero (NRZ) is achieved using an MM-LD. The MM-LD is adopted for a wide range of bit-rates between 2-10 Gbit/s by tuning the DC bias. Data format transformation from 10-Gbit/s return-to-zero optical signals to NRZ optical-signals is achieved with error free operation. Converted optical signals, which have a narrower spectral bandwidth and lower peak power than when input, are transmitted using a 1.3-μm zero dispersion fiber (1.3Aλ0-SMF).

Photonic memory switch: monolithic integration of a voltage-controlled bistable laser diode and an optical gate

An electrically controlled photonic memory switch which monolithically integrates a voltage-controlled bistable laser diode and an optical gate on an InP substrate is fabricated. Time-division optical signal processing such as pulsewidth conversion and a pulse delay control is successfully demonstrated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Linear voltage to frequency and voltage to pulse width converters using unijunction transistors†

Abstract Applications of semiconductors to power systems, for example to thyristor inverter frequency control, require voltage to frequency conversion in a pulse mode, particularly at low frequencies. Voltage to pulse width conversion might be necessary for sampling pulses. Voltage to frequency and voltage to pulse width converters with almost linear characteristics utilizing unijunction transistors have been designed and investigated. Arrangements for both of these conversions are incorporated in the same circuit to give an independent control as well as is possible.

Linear voltage-amplitude to pulse-width conversion utilizing a controlled unijunction monostable multivibrator

A circuit that achieves linear wide-range voltage-amplitude to pulse-width conversion is presented. The circuit combines a unijunction transistor operating in an inverted mode, a field- effect transistor, and an integrated circuit flip-flop to obtain highly linear conversion. Other advantages are low-ments, excellent interface characteristics, asynchronous operation, simplicity, and a wide range of pulse-width variation. The circuit operation is discussed, and major design equations are derived. In the experimental circuit that is included, linearity of conversion is within 0.5 percent of full scale pulse width. The pulse width is controllable over the range of 85 to 6 ms for a control voltage variation of 0 to 1.6 volts.

Modulated pulse audio power amplifiers for integrated circuits

Silicon monolithic circuits are best suited for applications with low power dissipation. Conventional approaches to audio power amplifiers have a rather limited efficiency, and are therefore not necessarily the best choice for integrated circuits. Pulse-width modulation, however, promises an efficiency of up to 100 percent and has several other advantages. Three approaches to amplitude to pulse-width conversion are discussed and compared: comparison of the audio signal with a triangle waveform, switching stages with hysteresis and RC feedback, and modified multivibrators. Possible configurations of output stages are listed. The use of complementary transistors results in higher efficiency and lower distortion.

A low-level linear rundown circuit for pulse-height to pulse-width conversion

The two-transistor linear rundown circuit analyzed here is desirable because of its size and economy. The circuit uses one transistor for the constant-current generator and another for an emitter-follower. Waveforms obtained from both experimental and theoretical analysis correlated well enough to plot them as a single waveform. With the addition of a differentiating circuit, this rundown circuit is well suited for the problem of low-level pulse-height to pulse-width conversion.