AIC1639 Datasheet, PDF (1/11 Pages) Analog Intergrations Corporation – 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER

AIC1639
FEATURES
l Guaranteed Start-Up from Below 0.9 V.
l High Efficiency.
l Low Quiescent Current.
l Few Number of External Components needed.
l Low Ripple and Low Noise.
l Fixed Output Voltage: 2.7, 3.0V, 3.3V, and 5V.
l Driver for External Transistor.
l Space Saving SOT-89 and TO-92 Packages.
APPLICATIONS
l Pagers.
l Cameras.
l Wireless Microphones.
l Pocket Organizers.
l Battery Backup Suppliers.
l Portable Instruments.
3-PIN ONE-CELL STEP-UP DC/DC CONVERTER
SPEC NO: DS-1639-00 05/26/00
DESCRIPTION
The AIC1639 is a high efficiency step-up DC/DC
converter for applications using 1 to 4 battery cells.
Only three external components are required to de-
liver a fixed output voltage of 2.7, 3.0V, 3.3V, or 5V.
The AIC1639 starts up from below 0.9V input with
1mA load. Pulse Frequency Modulation scheme
brings optimized performance for applications with
light output loading and low input voltages. The out-
put ripple and noise are lower compared with the
circuits operating in PSM mode.
The PFM control circuit operating in 100KHz (max.)
switching rate results in smaller passive compo-
nents. The space saving SOT-89 and TO-92 pack-
ages make the AIC1639 an ideal choice of DC/DC
converter for space conscious applications, like
pagers, electronic cameras, and wireless micro-
phones.
Provided with an external transistor driver pin (EXT),
the AIC1639 is recommended for applications re-
quiring current as large as several tens to several
hundreds of milli-amperes.
TYPICAL APPLICATION CIRCUIT
VIN
+ _C2
47µF
L1
33 µH
Q1
2SD1803
R1 300
EXT
10nF
D1
AIC1639-27
AIC1639-30
AIC1639-3 3
AIC1639-50
VOUT
+
GND
V_OUT
C2
100µF
100mA Load Current Step-Up Converter
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. TEL: [phone] FAX:[phone]
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