MIC3230/1/2

Constant Current Boost Controller for

Driving High Power LEDs

Bringing the Power to Light is a trademark of Micrel, Inc.

MicroLeadFrame and MLF are registered trademarks of Amkor Technology.

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

November 2009

M9999-113009-B

General Description

The MIC3230/1/2 are constant current boost switching

controllers specifically designed to power one or more

strings of high power LEDs. The MIC3230/1/2 have an

input voltage range from 6V to 45V and are ideal for a

variety of solid state lighting applications.

The MIC3230/1/2 utilizes an external power device which

offers a cost conscious solution for high power LED

applications. The powerful drive circuitry can deliver up to

70W to the LED system. Power consumption has been

minimized through the implementation of a 250mV

feedback voltage reference providing an accuracy of ±3%.

The MIC323x family is dimmable via a pulse width

modulated (PWM) input signal and also features an enable

pin for low power shutdown.

Multiple MIC3230 ICs can be synchronized to a common

operating frequency. The clocks of these synchronized

devices can be used together in order to help reduce noise

and errors in a system.

An external resistor sets the adjustable switching

frequency of the MIC3230/1. The switching frequency can

be between 100kHz and1MHz. Setting the switching

frequency provides the mechanism by which a design can

be optimized for efficiency (performance) and size of the

external components (cost). The MIC323x family of LED

drivers also offer the following protection features: Over

voltage protection (OVP), thermal shutdown and under-

voltage lock-out (UVLO).

The MIC3231 offers a dither feature to assist in the

reduction of EMI. This is particularly useful in sensitive EMI

applications, and provides for a reduction or emissions by

approximately 10dB.

The MIC3232 is a 400kHz fixed frequency device offered

in a small 10-pin MSOP package. The MIC3230/1 are

offered in both the EPAD 16-pin TSSOP package and the

12-pin 3mm × 3mm MLF

Datasheets and support documentation can be found on

Micrel’s web site at: www.micrel.com.

Bringing the Power to Light

Features

• 6V to 45V input supply range

• Capable of driving up to 70W

• Ultra low EMI via dithering on the MIC3231

• Programmable LED drive current

• Feedback voltage = 250mV ±3%

• Programmable switching frequency (MIC3230/1) or

400kHz fixed frequency operation (MIC3232)

• PWM Dimming and separate enable shutdown

• Frequency synchronization with other MIC3230s

• Protection features:

Over Voltage Protection (OVP)

Over temperature protection

Under-voltage Lock-out (UVLO)

• Packages:

IADJ

IS

6

5

1

VIN

EN

PWMD

COMP

10 VDD

DRV

PGND

OVP

9

8

7

2

3

4

IADJ

IS

VIN

EN

PWMD

COMP

1

VDD

DRV

PGND

OVP

2

3

4

5

FS

EPAD

SYNC/NC

6

8

12

11

10

9

7

1

N/C

VIN

EN

PWMD

COMP

IADJ

FS

AGND

16 N/C

VDD

DRV

PGND

OVP

IS

SYNC/NC

N/C

15

14

13

12

11

10

9

2

3

4

5

6

7

8

EPAD

MIC3232

10-pin MSOP

MIC3230/1

12-pin MLF

®

MIC3230/1

16-pin TSSOP

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

Applications

• Street lighting

• Solid state lighting

• General illumination

• Architectural lighting

• Constant current power supplies