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pulse width modulation What is pulse width modulation (PWM)? Search results

What is pulse width modulation (PWM)?
Pulse Width Modulation (PWM) is a way of digitally encoding analogue signal levels. Through the use of high-resolution counters, the duty cycle of a square wave is modulated to encode a specific analogue signal level. In more general terms, a switch is opened and closed in timed pulses, where the time the switch is closed is determines the power output.
Basically, a PWM variable-power scheme switches the power quickly between fully ON and fully OFF tens or hundreds of kHz in the case of a computer power supply (which has a regulated output). The switching rate is much faster than what would affect the load. The term duty cycle describes the proportion of ON time to the regular interval or period of time. A low duty cycle corresponds to low power because the power is off for most of the time. Duty cycle is expressed in percent, 100% being fully ON.
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2001-04-19 Three and four phase brushless dc motor controllers using pulse-width modulation
This application note describes LSI Computer Systems' five motor circuits (LS7260, LS7261, LS7262, LS7263 and LS7264) that drive brushless DC motor controllers.
2001-10-10 M16C/62: Pulse width modulation
This application note describes the operations of PWM for the M16C/62 microcontroller. A sample assembly program is presented to demonstrate the basic functions of PWM.
2006-12-27 Use pulse-shape filtering for smooth transitions
Filters are an important part of communications systems. They are used to eliminate spectral leakage, reduce channel width, and eliminate interference from adjacent symbols (ISI
2009-02-05 Using SPWM eTPU function
Here are C interface routines to the synchronised pulse-width modulation eTPU function.
2012-12-04 Using simplified inverters for commercial solar PV
A bipolar sine PWM technique is implemented on a single phase H-Bridge inverter in real time using F28335eZDSP.
2011-01-21 Temp sensor IC optimised for LED efficiency
Seiko Instruments reveals the S-5855A series PWM output temperature sensor IC designed for LED lighting systems in PC laptops, tablets or other devices requiring temperature control.
2006-04-25 Supertex unveils PXM fan speed controller IC
Supertex Inc. has unveiled PWM fan speed controller which has a wide input voltage range of 16V to 90V, making its suitable for use in 24V and 48V systems.
2002-06-20 Stability and biasing for PWM amplifiers
This application note describes the stability and biasing of PWM amplifiers.
2007-10-31 ST PWM controllers suit motherboard, POL apps
ST has launched four new PWM controllers that integrate a voltage reference, control logic, gate drivers, monitoring and protection circuits into standard SO-8 or tiny 3-by-3mm DFN packages.
2014-01-24 Solutions for single-device PWM waveform generator
Know the ways to implement a single-device standalone analog PWM waveform generator.
2008-10-20 Six-phase controllers enhance energy efficiency
ON Semi has introduced the first 6-phase Pulse Width Modulation (PWM) controllers.
2007-04-13 SH7641 series: Output of three-phase PWM signals and the corresponding inverse signals
This article describes the technique to output three-phase PWM signals and the corresponding inverse signals. It controls high-level width of pulses in order to manipulate the duty cycles of pulse-waveform signals
2008-12-18 PWM operating at different levels of frequency, power
Learn how to implement a PWM with three op amps from a single quad-op-amp chip.
2013-10-18 PWM margining with power-supply system manager
Know the effect of PWM on the power-supply output-voltage noise, the enabling and disabling of PWM, and the impact of the PWM lowpass filter.
2002-07-01 PWM easing digital control of analog circuits
By controlling analog circuits digitally, system costs and power consumption can be drastically reduced.
2013-02-11 PWM dimming for LEDs
Here's an LED driver that aims to combine the simplicity of analogue dimming with the accuracy of PWM dimming by generating its own PWM signal.
2006-02-06 PWM controllers deliver ±0.5% accuracy
Intersil Corp. has introduced a family of VR11 pulse width modulation controllers with the industry's highest accuracy.
2009-11-30 PWM controller handles 15W-65W output power
The controller's frequency and peak current modulation creates efficiency levels of 85 per cent at full load and high efficiency over the entire load range
2005-10-18 PWM advances active-clamp converter designs
National Semiconductor says its LM5026 pulse-width-modulation controller is the industry's most advanced type for forward converter toplogies using an active-clamp/reset design.
2008-01-14 Need to estimate buck converter efficiency in portable apps?
Here is an in-depth efficiency analysis for buck converters in PWM and PFM modes in portable applications.
2011-07-08 MTU2 asymmetric complementary PWM output
Here's a document by Renasas Electronics that describes a sample program for outputting an asymmetric complementary pulse width modulationwaveform
2003-12-16 MCUs with PPG can function as PWM and DAC
MCUs that include built-in 16bit PPG timers can be configured in PWM mode to generate waveforms with varied pulse width at a constant period, in synchronization with a dedicated external or software trigger
2006-05-10 Maxim's new constant current source delivers 350mA
Maxim Integrated Products has introduced an adjustable constant current source that provides up to 350mA of current to one or more strings of high-brightness LEDs.
2006-03-21 IR introduces 600kHz PWM controller IC
International Rectifier introduced the IR3624, a 600kHz single-phase synchronous buck PWM controller IC designed for high density, 10A non-isolated POL regulators used in networking and communication systems.
2013-10-25 Implement single-device PWM waveform generator
Know the two methods for implementing a stand-alone analogue PWM waveform generator.
2014-04-15 I/O sync techniques for complex embedded designs
Know the challenges of dealing with a heterogeneous mix of I/O types and some strategiesfor dealing with them.
2007-11-23 FET pre-driver touts full PWM range
Freescale has introduced a FET pre-driver that provides a cost-effective solution for apps, which require synchronous and asynchronous three-phase motors to combine high output performance, high reliability and small size for space-constrained designs..
2003-09-15 Fan health monitoring and the MIC502
This application note presents a fan monitoring circuit that can be used in conventional MIC502-based circuits employing pulse-width modulation (PWM) fan speed control.
2014-11-20 Employing programmable SoC for fan control
Here's a tutorial on implementing the electronics for 2-, 3-, and 4-wire fan motor controllers using Cypress Semiconductor's programmable SoC components.
2009-04-09 DSM with HB LED controllers
Here's an overview of delta sigma modulation used in LED dimming applications
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