AME
AME5144
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General Description
High Efficiency, 37V Step-Up
Converter for 2 to 10 White LEDs
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Features
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Up to 10 LEDs at 25mA
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86% Efficiency
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1.7% Current-Regulation Accuracy
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Output Overvoltage Protection
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Flexible Dimming Control
Analog
Direct-PWM Internal Filter
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1MHz PWM Switching Frequency
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0.1uF Output Capacitor
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Soft-Start Eliminates Inrush Current
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2.6V to 5.5V Input Range
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0.3uA Shutdown current
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DFN 3mm x 3mm x 0.75mm Package with
Exposed Paddle
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All AME’ s Lead Free Products Meet RoHS
Standards
The AME5144 is an efficient driver for up to ten white
LED applications. They are ideal for large LCD backlight
displays in Cell Phone, PDAs, and other handheld devices.
The AME5144 is switch-mode boost converter with con-
stant LED current, rather than output voltage. The series
connection allows the LED currents to be identical for uni-
form brightness and minimizes the number of trace to the
LEDs. The AME5144 drives series-connected LEDs to
controlled-current pin which connected a typically 13Ω
sense resistor, not an expensive fraction-ohm value.
Fast 1MHz current-mode PWM operation allows for small
input and output capacitors and a small inductor while mini-
mizing ripple on the input supply/battery. Soft-start elimi-
nates inrush current during startup. To control LED bright-
ness, the LED current can be pulsed by applying a single
analog/PWM signal with a frequency range from 200Hz to
30KHz for the control pin CTRL.
The AME5144 is available in space saving, 8 pin, 3mm x
3mm x 0.75mm DFN package.
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Applications
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Cell Phones and Smart Phones
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PDAs, Palmtops, and Wireless Handhelds
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e-Books and Subnotebooks
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White LED Display Backlighting
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Rev.D.01
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AMETHERM [ AMETHERM CIRCUIT PROTECTION THERMISTORS ]
