AME
AME5248
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General Description
The AME5248 is a fixed-frequency current mode syn-
chronous PWM step down converter that is capable of
delivering 600mA output current while achieving peak effi-
ciency of 95%. Under light load conditions, the AME5248
operates in a power saving mode that consumes just
around 20µA of supply current, maximizing battery life in
portable applications. The AME5248 operates with a fixed
frequency of 1.5MHz, minimizing noise in noise-sensi-
tive applications and allowing the use of small external
components. The AME5248 is an ideal solution for appli-
cations powered by Li-Ion batteries or other portable ap-
plications that require small board space.
The AME5248 is available in a variety of fixed output
voltage options, 1.0V, 1.2V, 1.3V, 1.5V, 1.8V, 2.5V, 2.7V,
2.8V, and 3.3V, and is also available in an adjustable
output voltage version capable of generating output volt-
ages from 0.6V to V
IN
. The AME5248 is available in the
tiny 5-pin SOT-25 and TSOT-25 package.
1.5MHz, 600mA
Synchronous Buck Converter
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Applications
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Blue Tooth Headsets
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Portable Audio Players
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Mobile Phones
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Wireless and DSL Modems
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Digital Still Cameras
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Portable Instruments
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Typical Application
V
IN
2.5V to 5.5V
IN
C
IN
4.7µF
SW
L
4.7µH
V
OUT
AME5248
EN
GND
FB
C
OUT
10µF
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Features
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High Efficiency - Up to 95%
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Very Low 20µA Quiescent Current
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Guaranteed 600mA Output Current
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1.5MHz Constant Frequency Operation PWM
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Internal Synchronous Rectifier Eliminates
Schottky Diode
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Adjustable Output Voltages From 0.6V to V
IN
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Fixed Output Voltage Options Available 1.0V,
1.2V, 1.3V, 1.5V, 1.8V, 2.5V, 2.7V, 2.8V and
3.3V
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100% Duty Cycle Low-Dropout Operation
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0.1µA Shutdown Current
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Require Tiny Capacitors and Inductor
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Tiny SOT-25 and TSOT-25 Package
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All AME's Lead Free Products Meet RoHS
Standards
V
IN
2.5V to 5.5V
IN
C
IN
4.7µF
SW
C1
22p F
R1
887K
R2
442K
C
OUT
10µF
L
4.7
µH
V
OUT
1.8V/600mA
Figure 1. Fixed Voltage Regulator
AME5248
EN
GND
FB
Figure 2. Adjustable Voltage Regulator
Rev.A.01
1
AME
AME5248
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Pin Description
Pin Number
1
2
1.5MHz, 600mA
Synchronous Buck Converter
Pin Name
IN
GND
Pin Description
Input Supply Voltage Pin.
Bypass this pin with a capacitor as close to the device as possible
Ground
Tie directly to ground plane.
Enable Control Input.
The enable pin is an active high control. Tie this pin above 1.4V to enable the
device. Tie this pin below 0.4V to shut down the device. In shutdown, all
function are disabled. Do not leave EN pin floating.
FB:Output voltage Feedback input.
Set the output voltage by selecting values for R1 and R2 using: R1 = R2
(V
OUT
/0.6V -1)
Connect the ground of the feedback network to an AGND (Analog Ground)
plane which should be tied directly to the GND pin.
OUT:Output Pin
Switch Node Connection to Inductor.
3
EN
4
FB/OUT
5
SW
4
Rev.A.01
Analog electronics
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