LM2793 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – Low Noise White LED Constant Current Supply with Dual Function Brightness Control

LM2793
www.ti.com
SNVS228 – MAY 2004
LM2793 Low Noise White LED Constant Current Supply with Dual Function Brightness
Control
Check for Samples: LM2793
FEATURES
1
•2 Two Regulated Current Outputs, up to 16mA
Each, Matched to Within ±0.3% (typ.)
• High Efficiency, 1.5× Regulated Charge Pump
• Input Voltage Range: 2.7V to 5.5V
• Soft Start Limits Inrush Current
• Analog Voltage Brightness Control
• PWM Brightness Control
• Very Small Solution Size - NO INDUCTOR
• 500kHz Switching Frequency
• 3µA (typ.) Shutdown Current
• LLP-10 Package: 3.0mm X 3.0mm X 0.8mm
APPLICATIONS
• White LED Display Backlights
• White LED Keypad Backlights
• 1-Cell LiIon Battery-Operated Equipment
Including PDAs, Hand-held PCs, Cellular
Phones
• Flat Panel Displays
DESCRIPTION
The LM2793 is a highly efficient, semi-regulated 1.5x CMOS charge pump that provides dual constant current
outputs. The LM2793 has an input voltage range of 2.7V to 5.5V.
To control LED brightness, the amount of current driven to the current-mode outputs can be adjusted with an
analog voltage and/or a pulse-width-modulated (PWM) square wave.
Pre-regulation of the charge pump minimizes conducted noise on the input. Combined with a fixed switching
frequency of 500kHz, the LM2793 is a low-noise solution.
The LM2793 is available in a 10-pin Leadless Lead-frame package: LLP-10.
Typical Application Circuit
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2004, Texas Instruments Incorporated