AIC1553
Compact 500KHz PWM/PFM, Step-Down DC/DC
Converters
FEATURES
Tiny 5-Lead SOT-23 package
Uses Tiny Capacitors and Inductor
High Frequency Operation: 500KHz
High Output Current: 500mA
Low R
DS(ON)
Internal Switch: 0.6Ω
High Efficiency: Up to 90%
Current Mode Operation for Excellent Line and
Load Transient Response
Short-Circuit Protected
Low Quiescent Current: 22µA
Low Dropout Operation: 100% Duty Cycle
Ultralow Shutdown Current: I
Q
< 1µA
Peak Inductor Current Independent of Inductor
Value
Low Output Voltages: Down to 0.75V
DESCRIPTION
The AIC1553 is a step-down, current mode,
DC/DC converter. It operates from 2.5V to 5.5V
input voltage range and switches at 500KHz,
allowing the use of tiny, low cost capacitors and
inductors. The output voltage is adjustable from
0.75V to 5V. A built-in 0.6Ω switch allows up to
0.5A of output current at high efficiency.
The AIC1553 operates continuously to very low
load currents to provide low ripple at the
expense of light load efficiency. With no load,
the AIC1553 draws only 22µA. In shutdown
mode, it draws less than 1µA, making it ideal for
current sensitive applications.
The tiny 5-lead SOT-23 package makes it
easy to save the layout area.
APPLICATIONS
Cellular Phones.
PDAs and Handy-Terminals.
CPU I/O Supplies.
Cordless Phones.
Notebook Chipset Supplies.
Handheld Equipment
TYPICAL APPLICATION CIRCUIT
U1
V
IN
2.5V~5.5V
5
+ C1
10µF
VIN
SW
1
L1
6.8µH
C3
22pF
R2
560K
R1
240K
C2
47µF
V
OUT
2.5V
D1
SS12
3
C4
4.7µF
GND 2
4 SD
VFB
ON/OFF
AIC1553
2.5V/500mA Step-Down Converter
Analog Integrations Corporation
4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
DS-1553-P2 061402
1
AIC [ ANALOG INTERGRATIONS CORPORATION ]
