LM2791 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – Current Regulated Switched Capacitor LED Driver with Analog Brightness Control

Not Recommended For New Designs
LM2791
www.ti.com
SNVS156M – FEBRUARY 2001 – REVISED MAY 2013
LM2791 Current Regulated Switched Capacitor LED Driver with Analog Brightness
Control
Check for Samples: LM2791
FEATURES
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•2 Output Matching of ± 0.3%
• Drives up to Two LEDs
• 3V to 5.8V Input Voltage
• Up to 36mA Output Current
• Soft Start Limits Inrush Current
• Analog Brightness Control
• Separate Shutdown Input
• Very Small Solution Size - No Inductor
• 0.7mA Typical Operating Current
• 1µA (max.) Shutdown Current
• 450kHz Switching Frequency (min.)
• Linear Regulation Generates Predictable Noise
Spectrum
• WSON-10 Package: 3mm X 3mm X 0.8mm
APPLICATIONS
• White LED Display Backlights
• White LED Keypad Backlights
• 1-Cell Li-Ion Battery-Operated Equipment
Including PDAs, Hand-Held PCs, Cellular
Phones
• Flat Panel Displays
DESCRIPTION
The LM2791 is a CMOS charge-pump voltage
doubler and regulator that provides two regulated
current sources. The LM2791 is designed to drive two
white (or blue) LEDs with matched currents (within ±
0.3%) to produce balanced light sources for display
backlights. They accept an input voltage range from
3V to 5.8V and maintain a constant current
determined by an external set resistor.
The LM2791 delivers up to 36mA of load current to
accommodate two high forward voltage (typically
white) LEDs. The switching frequency is 450kHz
(min.) to keep the conducted noise spectrum away
from sensitive frequencies within portable RF
devices.
In the LM2791, brightness is controlled by applying a
voltage between GND and 3.0V to the BRGT pin. The
LM2791 is available in active high or low shutdown
versions. The shutdown pin reduces the operating
current to 1µA (max.).
The LM2791 is available in a 10 pin WSON CSP
package.
Basic Application Circuit
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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.
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