LM2756 - Multi-Display Inductorless LED Driver with 32 Exponential Dimming Steps in micro SMD from the PowerWise® Family
Datasheet Packaging Samples & Pricing Eval. Boards Application Notes Knowledge Base

Features
Drives up to 8 LEDs with up to 30mA of Diode Current Each
32 Exponential Dimming Steps with 800:1 Dimming Ratio for Group A (Up to 6 LEDs)
8 Linear Dimming States for Groups B (Up to 3 LEDs) and D1C (1 LED)
Programmable Auto-Dimming Function
3 Independently Controlled LED Groups Via I 2C Compatible Interface
Up to 90% Efficiency
Total Solution Size < 21mm 2
Low Profile 20 Bump micro SMD Package (1.615mm × 2.015mm × 0.6mm)
0.4% Accurate Current Matching
Internal Soft-Start Limits Inrush Current
True Shutdown Isolation for LED’s
Wide Input Voltage Range (2.7V to 5.5V)
Active High Hardware Enable

General Description


The LM2756 is a highly integrated, switched-capacitor, multi-display LED driver that can drive up to 8 LEDs in parallel with a total output current of 180mA. More...


Applications


Dual Display LCD Backlighting for Portable Applications
Large Format LCD Backlighting
Display Backlighting with Indicator Light
  Typical Application
*click for larger image

Typical Application Circuit

ParametersValues
Regulated LEDs 8
Total LED Current 180 mA
Current Matching 0.5%
Boost Type Switched Capacitor Multi-Gain
Switching Frequency 1300 kHz
Efficiency (peak) 92 %
Input Min Voltage 2.7 Volt
Input Max Voltage 5.5 Volt
Boost Voltage Regulated
LED Configuration Parallel
Supply Current 2.1 mA
Switching Type Fixed Freq
Special Features Programmable Auto Dimming
PWM BrightCtrl No
Analog-V BrightCtrl Yes
Ambient Light Compensation No
RGB-LED No
Temperature Min -30 deg C
Temperature Max +85 deg C
RegType WhiteLED Driver
PowerWise Yes


Typical Performance


click for larger image

efficiency 3 different VFs
  Additional Resources
Application Notes


Block Diagram


*click for larger image

Block Diagram

Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM2756 Multi-Display Inductorless LED Driver with 32 Exponential Dimming Steps in micro SMD 511
Kbytes
5-Dec-07 Download

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Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders
Budgetary PricingStd
Pack
Size
Package
Marking
Format
TypePinsSpec.MSL
Rating
Peak
Reflow
RoHS
Report
CAD
Symbols
WeeksQtyQty$US each
LM2756TMEVMulti-Display Inductorless LED Driver with 32 Exponential Dimming Steps in micro SMDFull productionN/A
 
Buy Now
1+$100.001-
6 weeksN/A
LM2756TMMICRO SMD20NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now
1K+$1.80reel
of
250
XYTT
I DK
6 weeksN/A
LM2756TMXMICRO SMD20NOPB1260RoHS N/A Full productionN/A
 
Buy Now
1K+$1.80reel
of
3000
XYTT
I DK
6 weeksN/A

General Description


The LM2756 is a highly integrated, switched-capacitor, multi-display LED driver that can drive up to 8 LEDs in parallel with a total output current of 180mA. Regulated internal current sources deliver excellent current and brightness matching in all LEDs.

The LED driver current sinks are split into three independently controlled groups. The primary group (Group A) can be configured to drive four, five or six LEDs for use in the main phone display, while the secondary group (Group B) can be configured to drive one, two or three LEDs for driving secondary displays, keypads and/or indicator LEDs. An additional driver, D1C, is provided for additional indicator lighting functions.

The device provides excellent efficiency without the use of an inductor by operating the charge pump in a gain of 3/2 or in Pass-Mode. The proper gain for maintaining current regulation is chosen, based on LED forward voltage, so that efficiency is maximized over the input voltage range.

The LM2756 is available in National’s tiny 20-bump, 0.4mm pitch, thin micro SMD package.

Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1779: Application Note 1779 LM2756 Multi-Display Inductorless LED Driver with 32 Exponential Dimming Steps in µSMD 2288
Kbytes
31-Mar-08 Download
AN-1777: Application Note 1777 Designing Energy-Efficient Handheld Illumination Solutions 156
Kbytes
27-Feb-08 Download
AN-1777 (Chinese): Application Note 1777 Designing Energy-Efficient Handheld Illumination Solutions
306 Kbytes  

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More Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1269: Application Note 1269 LM2750-5.0 Evaluation Board 233
Kbytes
2-Oct-03 Download
AN-1302: Application Note 1302 LM2750-ADJ Evaluation Board 194
Kbytes
26-Mar-04 Download
AN-1998: Application Note 1998 How to Meet the HDMI 5V Source Requirement 117
Kbytes
28-Aug-09 Download
AN-1546: Application Note 1546 LM2754 Evaluation Board 927
Kbytes
3-Nov-06 Download
AN-1546 (Chinese): Application Note 1546 LM2754 Evaluation Board
393 Kbytes  
AN-1778: Application Note 1778 LM2755 Charge Pump LED Controller with I2C Compatible Interface in µSMD   4110
Kbytes
30-Apr-08 Download
AN-1695: Application Note 1695 LM2758 Flash LED Driver Evaluation Board 347
Kbytes
9-Apr-08 Download
AN-1731: Application Note 1731 LM2757 Evaluation Board 573
Kbytes
19-Feb-08 Download

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[Information as of 8-Nov-2009]