MIC3201

High Brightness LED Driver with

High-Side Current Sense

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

January 2010

M9999-011210-B

General Description

The MIC3201 is a hysteretic step-down, constant-current,

High-Brightness LED (HB LED) driver capable of driving

up to four, 1A LEDs. It provides an ideal solution for

interior/exterior lighting, architectural and ambient lighting,

LED bulbs, and other general illumination applications.

The MIC3201 operates with an input voltage range from

6V to 20V. 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 current sense resistor is

used to set the output current.

The MIC3201 offers a dedicated PWM input (DIM) which

enables a wide range of pulsed dimming. A high switching

frequency operation up to 1MHz allows the use of smaller

external components minimizing space and cost.

The MIC3201 operates from -40°C to 85°C and is

available in an 8-pin epad SOIC package.

Datasheets and support documentation can be found on

Micrel’s web site at: www.micrel.com.

Features

• 6.0V to 20V input voltage range

• High efficiency (>90%)

• ± 5% LED current accuracy

• High-side current sense

• Dedicated dimming control input

• Hysteretic control (no compensation!)

• 1A internal power switch

• Up to 1MHz switching frequency

• Adjustable constant LED current

• 5V on board regulator

• Over temperature protection

• –40°C to +125°C junction temperature range

• Available in an 8-Pin ePad SOIC package

Applications

• 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)

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Typical Application

MIC3201 Step-down LED Driver Circuit