AIC2359 Datasheet, PDF (1/11 Pages) Analog Intergrations Corporation – 1A Dual Synchronous Step-down DC/DC Converter

AIC2359
1A Dual Synchronous Step-down DC/DC Converter
 ^FEATURES
 Dual 1A Output
 2.5V to 5.5V Input Range
 Accurate Reference 0.6V Provides Low Output
Voltages
 Adjustable Output Voltage
 Up to 95% Efficiency
 Stable with Low ESR Output Ceramic Capaci-
tors
 No Schottky Diode Required.
 65µA Quiescent Current per Channel.
 100% Duty Cycle in Low Dropout Operation.
 1.5MHz Fixed-Frequency PWM Operation
 ^APPLICATIONS
 Digital Still Cameras
 Cellular Phones
 Wireless and DSL Modems
 Notebook Chipset Supplies.
 PDAs and Handy-Terminals.
 Battery-Operated Devices (1 Li-Ion or 3 NiMH/
NiCd).
 ^DESCRIPTION
The AIC2359 is a dual output, low-noise,
pulse-width-modulated (PWM), DC-DC step-
down converter. It powers logic and transmit-
ters in small wireless systems such as cellular
phones, communicating PDAs, and handy-
terminals.
The device features an internal synchronous
rectifier for high efficiency; it requires no exter-
nal Schottky diode. Internally fixed-frequency
1.5MHz operation provides easy post-filtering
and allows the use of small inductors and ca-
pacitors. The AIC2359 is ideally suited for Li-
Ion battery applications. PWM/PSM mode ex-
tends battery life by switching to a pulse-
skipping-modulated mode during light loads.
Shutdown mode places the device in standby,
reducing supply current to under 1µA..
Other features of the AIC2359 include high ef-
ficiency, soft start, over temperature protection,
and over current protection. It is available in a
space-saving
12-pin
DFN.
 ^{TYPICAL APPLICATIONS CIRCUIT}
Vin2
Vout1
2.2uH
L2
1
VIN2
EN2
12
4.7uF
Cin2
2
LX2
3
GND
NC2
11
FB2
10
R12
4
FB1
GND
9
5
NC1
LX1
8
6
22pF ^R11
EN1
VIN1
7
C11
AIC2359
10uF
Cout1
2.2uH
L1
Vout2
10uF
Cout2
R21
22pF
C21
R22
4.7uH
Cin1
Vin1
Fig. 1 Adjustable Output Voltage Step-Down DC/DC Converter
Analog Integrations Corporation
Si-Soft Research Center
3A1, No.1, Li-Hsin Rd. I , Science Park , Hsinchu 300, Taiwan , R.O.C.
TEL: [phone]
FAX: [phone]
DS-2359G-02 20120209
www.analog.com.tw
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