AME, Inc.
AME5170
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General Description
The AME5170 is a fixed off-time step-up DC/DC con-
verter in a small SOT-25 package. The AME5170 is ideal
for LCD panels requiring low current and high efficiency
as well as LED application for cellular phone backlighting,
PDAs, and other hand-held devices. The low 400ns off
time allows the use of tiny external components.
AME5170 is designed to drive up to four white LEDs in
series with a constant current from a single Li-lon bat-
tery. To control LED brightness, the LED current can be
adjusted by applying a PWM (pulse width modulated)
signal with a frequency range of 100Hz to 50KHz to the
EN pin.
Low Cost Micro Power
Boost DC/DC Converter
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Typical Application
V
IN
1.5V to 5V
C
IN
4.7µF
L1
2.2µH
V
OUT
= 5V
C
OUT
4.7µF
R1
100KΩ
EN
CF
20pF
IN
SW
AME5170
FB
GND
R2
33KΩ
Figure.1 Typical 5V Application
V
IN
1.5V to 5.5V
C
IN
4.7µF
L1
10µH
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Features
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0.7Ω Internal Switch
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Use Small Surface Mount Components
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Adjust Output Voltage up to 28V
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Input under Voltage Lockout
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0.1µA Shutdown Current Typical
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Small SOT-25 Package
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All AME's Lead Free Products Meet RoHS
Standards
V
OUT
= 12V
C
OUT
1µF
R1
240KΩ
IN
SW
AME5170
EN
GND
FB
R2
27KΩ
Figure.2 Typical 12V Application
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Applications
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LCD Bias Supplies
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White LED Back-Lighting
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Handheld Devices
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Digital Cameras
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Portable Applications
EN
V
IN
1.5V to 5.5V
C
IN
4.7µF
L1
10µH
V
OUT
= 20V
C
OUT
1µF
R1
510KΩ
IN
SW
AME5170
FB
R2
33KΩ
GND
Figure.3 Typical 20V Application
Rev.A.02
1
AME [ ANALOG MICROELECTRONICS ]
