描述 Description

The MIC2846A is a high efficiency White LED (WLED) driver featuring two low quiescent current LDOs. It is designed to drive up to six LEDs and greatly extend battery life for portable display backlighting and keypad backlighting in mobile devices. The MIC2846A architecture provides the highest possible efficiency by eliminating switching losses present in traditional charge pumps or inductive boost circuits. With a typical dropout of 40mV at 20mA, the MIC2846A allows the LEDs to be driven directly from the battery eliminating switching noise and losses present with the use of boost circuitry.The MIC2846A features Dynamic Averaged Matching? (DAM?) which is specifically designed to get the optimum matching despite process variations. This ensures a typical matching of ±1.5% between all six LED channels. The LED brightness is preset by an external resistor and can be dimmed using a single-wire digital control. The digital interface takes commands from digital programming pulses to change the brightness in a logarithmic scale similar to the eye's perception of brightness. The single-wire digital brightness control is divided into two modes of operation; full brightness mode or battery saving mode for a total of 49 brightness steps.The MIC2846A also features two independently enabled low quiescent current LDOs. Each LDO offers ±3% accuracy over temperature, low dropout voltage (150mV @ 150mA), and low ground current under all load conditions (typically 35μA). Both LDOs can be turned off to draw virtually no current.The MIC2846A operates over?a junction temperature range of -40°C to +125°C.

特性 Features

? High efficiency (no voltage boost losses)
? Dynamic Average Matching? (DAM?)
? Single wire digital control
? Input voltage range: 3.0V to 5.5V
? Dropout of 40mV at 20mA
? Matching better than ±1.5% (typical)
? Current accuracy better than ±1.5% (typical)
? Maintains proper regulation regardless of how many channels are utilized

簡介

MIC2846A屬于集成電路（IC）的LED驅(qū)動器。由制造生產(chǎn)的MIC2846ALED 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(biāo)稱固定電壓的電源為負(fù)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?？蓪ζ骷ぷ鼽c進行外部控制，可在照明應(yīng)用中用于實現(xiàn)調(diào)光功能。