What is pulse width modulation (PWM)?
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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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| 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. |
| 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. |
| 2010-11-30 | LED controller improves efficiency with PF correction TI rolls out the TPS92210, a single-stage, TRIAC-dimmable LED lighting pulse width modulation (PWM) controller solution that offers single-stage power factor correction for improved efficiency. |
| 2010-09-29 | Compact PWM clock covers 3.81Hz to 1MHz frequency Linear debuts the LTC6992 silicon oscillator, the latest member of the TimerBlox family that offers simple and accurate pulse width modulation (PWM) capability for output frequencies from 3.81Hz to 1MHz. |
| 2009-12-15 | Drivers bring compactness, dimming for LEDs The LED drivers offer analogue and pulse width modulation (PWM) dimming with a typical efficiency of 95 per cent. |
| 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. |
| 2009-04-09 | DSM with HB LED controllers Here's an overview of delta sigma modulation used in LED dimming applications. |
| 2009-02-05 | Using SPWM eTPU function Here are C interface routines to the synchronised pulse-width modulation eTPU function. |
| 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. |
| 2008-10-20 | Six-phase controllers enhance energy efficiency ON Semi has introduced the first 6-phase Pulse Width Modulation (PWM) controllers. |
| 2008-09-19 | Converting PCM to PWM audio with digital amplifiers Learn how digital amplifiers can convert pulse code modulation (PCM) into pulse width modulation (PWM). |
| 2008-05-01 | Make your machines talk Voice alerts for machines may be designed using a low-cost MCU with a pulse-width modulation (PWM) functionality that uses timers and interfaces to a memory. |
| 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. |
| 2007-12-12 | Boost converter eases design in POL apps TI has introduced a tiny, high-voltage boost converter that supports boost, SEPIC and flyback topologies, which are used to regulate single or dual Li-ion battery inputs. |
| 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.. |
| 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. |
| 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. |
| 2006-12-27 | Use pulse-shape filtering for smooth transitions Use pulse-shape filtering for smooth transitions |
| 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. |
| 2006-05-03 | Controller IC targets POL regulators IR has introduced a 600kHz single-phase synchronous buck pulse-width modulation controller IC designed for high density, 10A non-isolated point-of-load regulators. |
| 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. |
| 2006-03-23 | Actel designs IP core for nonvalatile FPGAs Actel Corp. has introduced CorePWM, a flexible PWM intellectual property IP building block for D/A conversion, designed for the company's nonvolatile FPGAs. |
| 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. |
| 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. |
| 2002-07-01 | PWM easing digital control of analog circuits By controlling analog circuits digitally, system costs and power consumption can be drastically reduced. |
| 2005-10-12 | DC/DC switching controller addresses active power apps ON Semiconductor announced that it has successfully developed a working silicon for its new dual-edge pulse width modulation (PWM) controller and delivery of engineering samples to leading VR11 power supply licensees. |
| 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. |
| 2001-04-19 | Three and four phase brushless dc motor controllers using pulse-width modulation Three and four phase brushless dc motor controllers using pulse-width modulation |
| 2001-05-09 | Creating a sine modulated PWM signal using the TMS320F240 EVM This application note describes how to generate an asymmetrical PWM signal with a varying duty cycle using the TMS320F240 assembly code. |
| 2001-10-10 | M16C/62: Pulse width modulation M16C/62: Pulse width modulation |
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