General Description

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 current sense 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°C to +125°C and is available in an 8-pin SOIC package.

A dither disabled version MIC3203-1 is also available in the same package as the MIC3203.

Features

• 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°C to +125°C junction temperature range

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)