描述 Description

The LX27901 is an extremely versatile high-performance controller for driving LEDs from the HVDC (output) rail of a standard PFC front-end. The controller allows the user to utilize three different converter drive schemes, LLC (resonant), conventional PWM control, and Microsemi’s proprietary synchronous scheme, all selectable by the multi-function ENABLE pin. In non-resonant mode, the controller provides two 180° phase-shifted pulse-width modulated drive signals for implementing various two-switch DC-DC converter topologies, such a half-bridge and asymmetrical forward converter. It can also be used for one-switch topologies. Direct PWM input dimming operation can be realized by inputting a suitable dimming pulse train to the DIM pin. The LX27901 supports analog LED current control utilizing the BRTA pin for setting the analog LED current. In addition, a proprietary dimming algorithm ACU_BRITE? is incorporated. The controller integrates the pulsed LED current and compares it with a reference for very accurate brightness control irrespective of duty cycle. The LX27901 is designed to operate with Microsemi’s proprietary lossless (magnetic) current balancing schemes. See more at? ?LX27901 Application Note for LED Backlight.document.write( String.fromCharCode(60)+'style type=\"text/css\">div#slider_slide_1____202___-1 { display: block !important; }'+String.fromCharCode(60)+'/style>' );document.write( ''+String.fromCharCode(60)+'style type=\"text/css\">div.slider_content_inactive { display: none; }.slider_title { display: none !important; }'+String.fromCharCode(60)+'/style>' );LX27901 NewsLX27901 Newsdocument.getElementById('slider_container_1____202___').setAttribute( 'class', document.getElementById('slider_container_1____202___').className.replace(/\\bslider_noscript\\b/,'') );Microsemi Backlighting Solutions Adopted by VIZIOMicrosemi Delivers New LED Driver for LCD Televisions

特性 Features

·LLC, PWM and proprietary synchronous modes to drive the LED strings
·LED strings can be dimmed by PWM or analog methods
·Proprietary algorithm to provide accurate brightness control at high efficiency over wide dimming duty cycle range
·Accurate parallel LED strings current matching using Microsemi’s patented non-dissipative current-balancing technology
·Robust protection from open or shorted LED conditions
·Dedicated fault indication
·0.8A Source & Sink Drive Capability
·On Chip 5.25V Regulator
·Direct connection to input voltage rail up to 27V
·Synchronous regulation function to minimize power conversion stage
  ROHS, PB Free

簡介

LX27901ID屬于集成電路（IC）的LED驅(qū)動器。由制造生產(chǎn)的LX27901IDLED 驅(qū)動器器件屬于 LED 驅(qū)動器電源管理集成電路 (PMIC) 系列，可通過標稱固定電壓的電源為負載（通常為發(fā)光二極管）提供電流，并且電流可控。它與用于電壓調(diào)節(jié)的類似產(chǎn)品的主要區(qū)別在于，這類器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通常可對器件工作點進行外部控制，可在照明應(yīng)用中用于實現(xiàn)調(diào)光功能。