LM2793LDEV National Semiconductor, LM2793LDEV Datasheet

BOARD EVALUATION LM2793LD

LM2793LDEV

Manufacturer Part Number
LM2793LDEV
Description
BOARD EVALUATION LM2793LD
Manufacturer
National Semiconductor
Series
PowerWise®r
Datasheets

Specifications of LM2793LDEV

Current - Output / Channel
16mA
Outputs And Type
2, Non-Isolated
Voltage - Output
4 V
Features
Charge Pump
Voltage - Input
2.7 ~ 5.5V
Utilized Ic / Part
LM2793
Lead Free Status / RoHS Status
Not applicable / Not applicable
© 2003 National Semiconductor Corporation
LM2793
Low Noise White LED Constant Current Supply with
Dual Function Brightness Control
General 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 fre-
quency 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
DS200636
Features
n Two Regulated Current Outputs, up to 16mA Each,
n High Efficiency, 1.5x Regulated Charge Pump
n Input Voltage Range: 2.7V to 5.5V
n Soft Start Limits Inrush Current
n Analog Voltage Brightness Control
n PWM Brightness Control
n Very Small Solution Size - NO INDUCTOR
n 500kHz Switching Frequency
n 3µA (typ.) Shutdown Current
n LLP-10 Package: 3.0mm X 3.0mm X 0.8mm
Applications
n White LED Display Backlights
n White LED Keypad Backlights
n 1-Cell LiIon Battery-Operated Equipment Including
n Flat Panel Displays
Matched to Within
PDAs, Hand-held PCs, Cellular Phones
±
0.3% (typ.)
20063602
February 2003
www.national.com

Related parts for LM2793LDEV

LM2793LDEV Summary of contents

Page 1

... Combined with a fixed switching fre- quency 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 © 2003 National Semiconductor Corporation Features n Two Regulated Current Outputs 16mA Each, Matched to Within n High Efficiency, 1.5x Regulated Charge Pump n Input Voltage Range: 2 ...

Page 2

Connection Diagram Ordering Information Order Number LM2793LD LM2793LDX Pin Description Pin Name C1- 3 C2 OUT SD-BRGT 9 GND 10 C2- www.national.com LM2793 10-pin Leadless Leadframe Package ...

Page 3

... Absolute Maximum Ratings 2) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications SD-BRGT Continuous Power Dissipation (Note 4) Junction Temperature (T ) J-MAX-ABS Storage Temperature Range Lead Temp. (Soldering, 5 sec.) ESD Rating (Note 5) Human Body Model ...

Page 4

... The equations above assume LEDs are connected to outputs D thorough analysis of maximum LED voltage, please refer to text sections of the datasheet (to appear in future datasheet revisions - in the interim, please contact National Semiconductor for more information). Note 10: Current sources are connected internally between P voltage. For current sources to regulate properly, a minimum headroom voltage must be present across them. Minimum required headroom voltage is proportional ...

Page 5

Typical Performance Characteristics SD-BRGT 1 2 LED Current vs. Input Voltage Efficiency vs. Input Voltage Quiescent Current vs. Input Voltage Unless otherwise specified 1µF. ...

Page 6

Typical Performance Characteristics SD-BRGT 1 2 (MLCC’s). (Continued) Output Resistance vs. Temperature www.national.com Unless otherwise specified 1µF. Capacitors are low-ESR multi-layer ceramic capacitors IN ...

Page 7

Application Information CIRCUIT DESCRIPTION The LM2793 is a 1.5x CMOS charge pump that provides two matched constant current outputs for driving up to 16mA through high forward voltage drop White LEDs from Li-Ion battery sources. The device has two regulated ...

Page 8

Application Information TABLE 2. White LED Selection Manufacturer Osram www.osram-os.com Nichia www.nichia.com PARALLEL DX OUTPUTS FOR INCREASED CURRENT DRIVE Outputs D and D may be connected together to drive single LED. In such a configuration, two parallel ...

Page 9

... National highly recommends a 1:1 ratio between the pack- age and the PCB thermal land. To further enhance thermal conductivity, the PCB thermal land may include vias to a ground plane. For more detailed instructions on mounting LLP packages, please refer to National Semiconductor Ap- plication Note AN-1187. 9 www.national.com ...

Page 10

... NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant ...

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