AIC1550
Low-Noise Synchronous PWM Step-Down
DC/DC Converter
FEATURES
95% Efficiency or up
800mA Guaranteed Output Current.
Adjustable Output Voltage from 0.75V to VIN
of a range from +2.5V to 6.5V.
Very Low Quiescent Current: 35µA (Typ.).
Fixed- 500KHz or Adjustable Frequency
Synchronous PWM Operation.
Synchronizable
external
Switching
Frequency up to 1MHz.
Accurate Reference: 0.75V (±2%).
100% Duty Cycle in Dropout.
Low Profile 8-Pin MSOP Package.
DESCRIPTION
The AIC1550 is a low-noise pulse-width-
modulated (PWM) DC-DC step-down converter.
It powers logic circuits in PDAs and small
wireless systems such as cellular phones,
handy-terminals.
The device features an internal synchronous
rectifier for high conversion efficiency. Excellent
noise characteristics and fixed-frequency
operation provide easy post-filtering. The
AIC1550 is ideally suited for Li-ion battery
applications. It is also suitable for +3V or +5V
fixed input applications. The device can operate
in either one of the following four modes.
(1)
Forced PWM mode
operates at a
fixed frequency regardless of the
load.
Synchronizable
PWM
mode
allows the synchronization by
using an external switching
frequency
with
a
minimum
harmonics.
PWM/PFM Mode
extends battery
life by switching to a PFM pulse-
skipping mode under light loads.
Shutdown mode
sets device to
standby, reducing supply current
to 0.1µA or under.
APPLICATIONS
PDAs.
Digital Still Cameras.
Handy-Terminals.
Cellular Phones.
C
PU I/O Supplies.
(2)
Cordless Phones.
Notebook Chipset Supplies.
Battery-Operated Devices (4 NiMH/
NiCd
or 1
Li-ion
Cells).
(3)
(4)
The AIC1550 can deliver over 800mA output
current. The output voltage can be adjusted
from 0.75V to VIN ranging from +2.5V to +6.5V.
Other features of the AIC1550 include low
quiescent current, low dropout voltage, and a
0.75V reference of ±2% accuracy. It is available
in a space-saving 8-pin MSOP package.
Analog Integrations Corporation
Si-Soft Research Center
3A1, No.1, Li-Hsin Rd. I , Science Park , Hsinchu 300, Taiwan , R.O.C.
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
DS-1550P-04 010405
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AIC [ ANALOG INTERGRATIONS CORPORATION ]
