A pulse generator is either an

electronic circuit An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electrical ...

''or'' a piece of

electronic test equipment Electronic test equipment is used to create signals and capture responses from electronic devices under test (DUTs). In this way, the proper operation of the DUT can be proven or faults in the device can be traced. Use of electronic test equipmen ...

used to generate rectangular

pulse In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the nec ...

s. Pulse generators are used primarily for working with digital circuits; related

function generator In electrical engineering, a function generator is usually a piece of electronic test equipment or software used to generate different types of electrical waveforms over a wide range of frequencies. Some of the most common waveforms produced ...

s are used primarily for

analog circuit Analogue electronics ( en-US, analog electronics) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels. The term "analogue" describes the proportional relati ...

Bench pulse generators

Simple bench pulse generators usually allow control of the pulse repetition rate (

frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

), pulse width, delay with respect to an internal or external trigger and the high- and low-voltage levels of the pulses. More sophisticated pulse generators may allow control over the

rise time In electronics, when describing a voltage or current step function, rise time is the time taken by a signal to change from a specified low value to a specified high value. These values may be expressed as ratiosSee for example , and . or, equivale ...

and

fall time In electronics, fall time (pulse decay time) t_f is the time taken for the amplitude of a pulse to decrease (fall) from a specified value (usually 90% of the peak value exclusive of overshoot or undershoot) to another specified value (usually 10 ...

of the pulses. Pulse generators are available for generating output pulses having widths (duration) ranging from minutes to under 1 picosecond. Pulse generators are generally

voltage source A voltage source is a two-terminal device which can maintain a fixed voltage. An ideal voltage source can maintain the fixed voltage independent of the load resistance or the output current. However, a real-world voltage source cannot supply unli ...

s, with true current pulse generators being available only from a few suppliers. Pulse generators may use digital techniques, analog techniques, or a combination of both techniques to form the output pulses. For example, the pulse repetition rate and duration may be digitally controlled but the pulse amplitude and rise and fall times may be determined by analog circuitry in the output stage of the pulse generator. With correct adjustment, pulse generators can also produce a 50%

duty cycle A duty cycle or power cycle is the fraction of one period in which a signal or system is active. Duty cycle is commonly expressed as a percentage or a ratio. A period is the time it takes for a signal to complete an on-and-off cycle. As a formu ...

square wave A square wave is a non-sinusoidal periodic waveform in which the amplitude alternates at a steady frequency between fixed minimum and maximum values, with the same duration at minimum and maximum. In an ideal square wave, the transitions b ...

. Pulse generators are generally single-channel, providing one frequency, delay, width and output.

Optical pulse generators

Light pulse generators are the optical equivalent to electrical pulse generators with rep rate, delay, width and amplitude control. The output in this case is light, typically from a LED or laser diode.

Multiple-channels

A new family of pulse generators can produce multiple channels of independent widths and delays and independent outputs and polarities. Often called digital delay/pulse generators, the newest designs even offer differing repetition rates with each channel. These

digital delay generator A digital delay generator (also known as digital-to-time converter) is a piece of electronic test equipment that provides precise delays for triggering, syncing, delaying, and gating events. These generators are used in many experiments, controls ...

s are useful in synchronizing, delaying, gating and triggering multiple devices, usually with respect to one event. One is also able to multiplex the timing of several channels onto one channel in order to trigger or even gate the same device multiple times. A new class of pulse generator offers both multiple input trigger connections and multiple output connections. Multiple input triggers allow experimenters to synchronize both trigger events and data acquisition events using the same timing controller. In general, generators for pulses with widths over a few microseconds employ digital counters for timing these pulses, while widths between approximately 1 nanosecond and several microseconds are typically generated by analog techniques such as RC (resistor-capacitor) networks or switched delay lines.

Microwave pulsers

Pulse generators capable of generating pulses with widths under approximately 100 picoseconds are often termed as "microwave pulsers" and typically generate these ultra-short pulses using Step recovery diode (SRD) or Nonlinear Transmission Line (NLTL) methods (for exampl

. Step Recovery Diode pulse generators are inexpensive, but typically require several volts of input drive level and have a moderately high level of random jitter (usually undesirable variation in the time at which successive pulses occur). NLTL-based pulse generators generally have lower jitter, but are more complex to manufacture and do not suit integration in low-cost monolithic ICs. A new class of microwave pulse generation architecture, the RACE (

Rapid Automatic Cascode Exchange Rapids are sections of a river where the river bed has a relatively steep stream gradient, gradient, causing an increase in water velocity and turbulence. Rapids are hydrology, hydrological features between a ''run'' (a smoothly flowing part of ...

) pulse generation circui

is implemented using low-cost monolithic IC technology and can produce pulses as short as 1 picosecond and repetition rates exceeding 30 billion pulses per second. These pulsers are typically used in military communications applications and low-power microwave transceiver ICs. Such pulsers, if driven by a continuous frequency clock, will act as microwave comb generators, having output frequency components at integer multiples of the pulse repetition rate, and extending to well over 100 gigahertz (for exampl

.

Applications

Pulses can be injected into a device that is under test and used as a stimulus, clock signal, or analyzed as they progress through the device, confirming the proper operation of the device or pinpointing a fault in the device. Pulse generators are also used to drive devices such as switches, lasers and optical components, modulators, intensifiers, and resistive loads. The output of a pulse generator may also be used as the modulation signal for a

signal generator A signal generator is one of a class of electronic devices that generates electrical signals with set properties of amplitude, frequency, and wave shape. These generated signals are used as a stimulus for electronic measurements, typically used i ...

. Non-electronic applications include those in material science, medical, physics, and chemistry.

Examples

* Ballistics testing uses high voltage pulse generato

* "Signal cable selection for Veritas Observatory" with <200 ps risetime pulse generato

* Single channel pulse generators were in existence in the 1950

* "Characterization of Permalloy films on high-bandwidth striplines" Journal of Magnetism and Magnetic Materials Volumes 272-276, Supplement 1, May 2004, Pages E1341-E1342 * "Protoporphyrin IX Occurs Naturally in Colorectal Cancers and Their Metastases

* Testing Silicon Strip Detector with IR Light Pulse Generato

{{commons category, Pulse generators * Toward Intrinsic Ferroelectric Switching in Multiferroic BiFeO

Electronic circuits Electronic test equipment