2017年9月全国英语等级考试二级阅读理解训练题(

High-Brightness LED Driver Controller with High-Side Current Sense

The MIC3203 is a hysteretic, step-down, constant-current, High-Brightness LED (HB LED) driver. It provides an ideal solution for interior/exterior lighting, architectural and ambient lighting, LED bulbs, and other general illumination applications.

The MIC3203 is well suited for lighting applications requiring a wide-input voltage range.

The hysteretic control gives good supply rejection and fast response during load transients and PWM dimming. The high-side current sensing and on-chip current-sense amplifier delivers LED current with ±5% accuracy. An external high-side currentsense resistor is used to set the output current.

The MIC3203 offers a dedicated PWM input (DIM) which enables a wide range of pulsed dimming. A high-frequency switching operation up to 1.5MHz allows the use of smaller external components minimizing space and cost. The MIC3203 offers frequency dither feature for EMI control.

The MIC3203 operates over a junction temperature from 40℃ to +125℃ and is available in an 8-pin SOIC package.

MIC3203 主要特性:

4.5V to 42V input voltage range

High efficiency (>90%)

±5% LED current accuracy

MIC3203: Dither enabled for low EMI

MIC3203-1: Dither disabled

High-side current sense

Dedicated dimming control input

Hysteretic control (no compensation!)

Up to 1.5MHz switching frequency

Adjustable constant LED current

Over-temperature protection

40℃ to +125℃ junction temperature range

MIC3203 应用:

Architectural, industrial, and ambient lighting

LED bulbs

Indicators and emergency lighting

Street lighting

Channel letters

12V lighting systems (MR-16 bulbs, under-cabinet lighting, garden/pathway lighting)


图1.MIC3203/MIC3203-1方框图