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PWM 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.
total search1130 articles
2009-09-22 White LED driver circuits for offline applications using standard PWM controllers
This application note discusses techniques for powering LEDs directly from the AC mains, not only to develop the requisite voltage and current, but also to deliver power from the AC mains with near unity power factor while using off-the-shelf constant frequency PWM controllers.
2008-11-11 Voltage regulator uses digital PWM controller
Ericsson Power Modules tout its BMR450 uses a highly integrated digital PWM controller.
2011-08-31 Utilise eTPU2, eQADC for PWM control on MCU
Know how to use the "enhanced Timing Processor" (eTPU2) PWM driver from the eTPU2 general function set to demonstrate an open-loop LED dimmer control system.
2005-06-03 Using the ISL6420 PWM controller evaluation board
This app note discusses the ISL6420 in a complete control and protection scheme for a high-performance dc/dc buck converter
2001-10-03 Using ST7 PWM signal to generate analog output (Sinusoid)
This application note presents how to use the ST72511R4's PWM and BRM (binary rate multiplier) generator for the generation of a 50Hz sinusoid tunable in average and amplitude.
2001-05-11 Using PWM output as a digital-to-analog converter on a TMS320C240 DSP
This application note presents a method for utilizing the on-chip PWM generators on Texas Instruments' TMS320C240 DSP for D/A conversion.
2004-12-16 Using cost-effective PWM controller for small power-offline apps
The article presents the development of a new PWM power-supply controller IC for universal input and low-power applications.
2009-07-21 Understand thermal derating aspects of PWM ICs
Learn how to construct and calibrate a thermal-derating box for evaluating the thermal performance of PWM controllers.
2001-05-09 TMS320C24x PWM full compare in symmetric mode
This application note presents applications of the TMS320C24x PWM DSP Full Compare, including up to six PWM, three PWM and three complemented PWM generation in symmetric mode.
2008-04-15 TI debts PWM-input amplifier power stage
TI has introduced the industry's first PWM-input 20W stereo Class-D power stage with closed-loop feedback.
2010-06-01 Supplement the MAX6948 WLED driver with external PWM control
This application note explains how to add external PWM intensity control to supplement a device's internal PWM. The MAX6948 WLED driver serves as the example device. Configuration settings and performance data are shown.
2009-09-23 Superjunction MOSFETs suit PFC, PWM stages
Infineon unveils devices for extremely low capacitive losses and very low area specific RDS(on) values.
2003-06-13 Step-up dc-dc converter (PWM): Monolithic IC MM1349
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.
2004-12-15 Speed error in PWM fan control systems
Speed error in PWM fan control systems
2004-12-15 Speed error in PWM fan control systems
This app note describes speed error in PWM fan control systems
2001-05-15 Space-vector PWM with TMS320C24x/F24x using hardware and software determined switching patterns
This application note gives an in-depth discussion of the theory and implementation of the space vector PWM technique using Texas Instruments' TMS320C24x/F24x DSP series.
2014-01-24 Solutions for single-device PWM waveform generator
Know the ways to implement a single-device standalone analog PWM waveform generator.
2010-08-13 Single-IC PWM modulator has 2% linearity
Some LED driver circuits achieve dimming by applying a variable duty cycle (PWM) to the LED. PWM drive exploits LED behaviour.
2009-12-02 Single output mobile-friendly PWM controller
The ISL6224 single PWM controller delivers high efficiency and tight regulation from a voltage regulating synchronous buck DC/DC converter.
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.
2007-04-13 SH7641 MCU: Output of three-phase complementary PWM signals
This article describes a sample task for output of three-phase complementary PWM waveforms along with corresponding inverse waveforms. It also includes non-overlapping sections.
2009-11-27 SG6742: Highly integrated green-mode PWM controller
This application note describes a detailed design strategy for a high-efficiency, compact flyback converter.
2006-05-08 PWM-embedded LED drivers suit video wall apps
Macroblock has announced PWM-embedded LED drivers increase refresh rate and provide 16-bit colour depths for better image and colour processing of video display panels.
2010-08-09 PWM-controlled 4-20mA transmitter is galvanically isolated
This loop-powered, 4-20mA precision transmitter includes a precision PWM signal coupler with galvanic isolation from the PWM signal source.
2009-09-29 PWM regulators trim total component cost
Intersil has released compact multi-phase PWM regulators that comply with the Intel Mobile Voltage Positioning specification.
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.
2007-10-16 PWM offers unique partition of SMPS functions
Microchip has announced 2MHz, high-speed PWM that contains a 1A integrated MOSFET driver, comparator for overvoltage protection, and both battery-current and voltage-sense amps in one small package.
2006-09-19 PWM motor driver targets office automation, industrial markets
Allegro MicroSystems Inc. has announced a DMOS full-bridge micro stepping PWM motor driver to complement their existing serial controlled micro stepping driver family.
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