MIC2841AYMT TR Micrel Inc, MIC2841AYMT TR Datasheet

MIC2841AYMT TR

Manufacturer Part Number

MIC2841AYMT TR

Description

IC LED DRIVR WHITE BCKLGT 10TMLF

Manufacturer

Micrel Inc

Type

Backlight, White LEDr

Datasheet

1.MIC2841AYMT_TR.pdf (13 pages)

Specifications of MIC2841AYMT TR

Constant Current

Yes

Topology

Linear (LDO), PWM

Number Of Outputs

Internal Driver

Yes

Type - Primary

Backlight, Flash/Torch

Type - Secondary

White LED

Frequency

500kHz

Voltage - Supply

3 V ~ 5.5 V

Mounting Type

Surface Mount

Package / Case

10-TMLF®

Operating Temperature

-40°C ~ 125°C

Current - Output / Channel

20mA

Internal Switch(s)

Yes

Lead Free Status / RoHS Status

Lead free / RoHS Compliant

Voltage - Output

Efficiency

Other names

576-3471-2

Current page: 1 of 13
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General Description

The MIC2841A is a high efficiency White LED (WLED)

driver designed to drive up to four WLEDs, greatly

extending battery life for portable display backlighting,

keypad backlighting and camera flash in mobile devices.

The MIC2841A provides the highest possible efficiency as

this architecture has no switching losses present in

traditional charge pumps or inductive boost circuits. The

MIC2841A provides four linear driver channels which

maintain constant current for up to four WLEDs. It features

a typical dropout of 40mV at 20mA. This allows the

WLEDs to be driven directly from the battery eliminating

switching noise/losses present with the use of boost

circuitry.

The MIC2841A features Dynamic Average Matching™

(DAM™) which is specifically designed to provide optimum

matching across all WLEDs. The four channels are

matched better than ±1.5% typical, ensuring uniform

display illumination under all conditions. The brightness is

controlled through an Ultra Fast PWM™ interface

operating down to less than 1% duty cycle.

The MIC2841A is available in the 2mm x 2mm 10-pin Thin

MLF

of -40°C to +125°C.

Datasheets and support documentation can be found on

Micrel’s web site at: www.micrel.com.

____________________________________________________________________________________________________________

Typical Application

Ultra Fast PWM, DAM and Dynamic Average Matching are trademarks of Micrel, Inc.

MLF and MicroLeadFrame are registered trademark Amkor Technology Inc.

June 2009

leadless package with a junction temperature range

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

LCD Display Backlight with Four WLEDs

GND

END

SET

U1 MIC2841AYMT

Control

PWM

Dropout

Linear

Driver

Low

Features

• High Efficiency (no Voltage Boost losses)

• Dynamic Average Matching™ (DAM™)

• Ultra Fast PWM™ control (200Hz to 500kHz)

• 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

• Available in a 10-pin 2mm x 2mm Thin MLF

Applications

• Mobile handsets

• Handset LCD backlighting

• Handset keypad backlighting

• Flash driver

• Digital cameras

• Portable media/MP3 players

• Portable navigation devices (GPS)

• Portable applications

408

High Efficiency 4 Channel Linear WLED

channels are utilized

) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

Driver with DAM™ and Ultra Fast

High Current Flash Driver

PWM™ Control

MIC2841A

END

SET

U1 MIC2841AYMT

Control

PWM

Dropout

Linear

Driver

Low

M9999-062909-C

package

Related parts for MIC2841AYMT TR

MIC2841AYMT TR Summary of contents

Page 1

... LCD Display Backlight with Four WLEDs Ultra Fast PWM, DAM and Dynamic Average Matching are trademarks of Micrel, Inc. MLF and MicroLeadFrame are registered trademark Amkor Technology Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 ( June 2009 MIC2841A High Efficiency 4 Channel Linear WLED Driver with DAM™ ...

Page 2

... Micrel Inc. Ordering Information Part Number Mark Code MIC2841AYMT Q1Y Note: ® 1. Thin MLF ▲ = Pin 1 identifier. ® 2. Thin MLF is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is halogen free. Pin Configuration Pin Description Pin Name Pin Number 1 VIN ...

Page 3

... Micrel Inc. Absolute Maximum Ratings Main Input Voltage (V ) .................................. –0.3V to +6V IN Enable Input Voltage (V ) ............................ –0.3V to +6V END LED Driver Voltage (V ) ............................ –0.3V to +6V D1-D4 Power Dissipation .....................................Internally Limited Lead Temperature (soldering, 10sec.)....................... 260°C Storage Temperature (T ) .........................–65°C to +150°C s (3) ESD Rating ...

Page 4

... Micrel Inc. Typical Characteristics June 2009 4 MIC2841A M9999-062909-C ...

Page 5

... Micrel Inc. Functional Characteristics June 2009 5 MIC2841A M9999-062909-C ...

Page 6

... Micrel Inc. Functional Diagram VDD D1...D4 END June 2009 BG 4 POR TSD Figure 1. MIC2841A Functional Block Diagram 6 VDD V-to-I 1.27V DIG CTRL & PWM OSC GND RSE T MIC2841A M9999-062909-C ...

Page 7

... Micrel Inc. Functional Description The MIC2841A is a four channel linear WLED driver. The WLED driver is designed to maintain proper current regulation with LED current accuracy of 1.5%, and typical matching of 1.5% across the four channels. The WLEDs are driven independently from the input supply and will maintain regulation with a dropout of 40mV at 20mA ...

Page 8

... Micrel Inc. Application Information Dynamic Average Matching (DAM™) The Dynamic Average Matching™ multiplexes four voltage references to provide highly accurate LED current and channel matching. The MIC2841A achieves industry leading LED channel matching of 1.5% across the entire dimming range. Ultra Fast PWM™ Dimming Interface The MIC2841A supports a wide range of PWM control signal frequencies from 200Hz to 500kHz ...

Page 9

... Micrel Inc. Figure 6. PWM Signal at 1% Duty Cycle (I Figure 7. PWM Signal at 20% Duty Cycle (I Figure 8. PWM Signal at 50% Duty Cycle (I June 2009 = 0.2mA) Figure 9. PWM Signal at 80% Duty Cycle (I avg Figure 10. PWM Signal at 100% Duty Cycle (I = 4mA) avg = 10mA) avg 9 MIC2841A ...

Page 10

... Micrel Inc. High Current Parallel Operation U1 MIC2841AYMT SET END PWM Control Figure 11. High Current LED Driver Circuit The linear drivers are independent of each other and can be used individually or paralleled in any combination for higher current applications. A single WLED can be driven with all 4 linear drivers by connecting D1 through D4 in parallel to the cathode of the WLED as shown in Figure 11 ...

Page 11

... Micrel Inc. Typical Application C1 1µF/6.3V R1 20.5K Bill of Materials Item Part Number C1608X5R0J105K 06036D105KAT2A C1 GRM188R60J105KE19D VJ0603G225KXYAT SWTS1007 D1 – D4 99-116UNC R1 CRCW060320K5F5EA R2 CRCW06032003FKEA U1 MIC2841AYMT Notes: 1. TDK: www.tdk.com 2. AVX: www.avx.com 3. Murata: www.murata.com 4. Vishay: www.vishay.com 5. Seoul Semiconductor: www.seoulsemicon.com 6. EverLight: www.everlight.com 7. Micrel, Inc.: www.micrel.com June 2009 ...

Page 12

... Micrel Inc. PCB Layout Recommendations June 2009 Top Layer Bottom Layer 12 MIC2841A M9999-062909-C ...

Page 13

... Micrel Inc. Package Information MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. ...

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