AIC1577 Datasheet, PDF (1/14 Pages) Analog Intergrations Corporation – External NMOS Step-Down PWM Controller

AIC1577
External NMOS Step-Down PWM Controller
FEATURES
N-Channel MOSFET Drive
Operating Input Voltage from 4.5V to 24V
Wide Ouput Range : 0.8V to 20V
±1.5% 0.8V Reference
Low Dropout Operation : 95% Duty Cycle
500KHz Fixed Constant Frequency
Low Standby Current, I_Q Typically 720µA
Logic-Control Micropower Shutdown
Output Overvoltage Protection
Internal Diode for Bootstrapped Gate Drive
Current Mode Operation for Excellent Line and
Load Transient Response
Available in an 8-Lead SO and MSOP Package
APPLICATIONS
LCD Monitor
Palmtop Computers, PDAs
Wireless Modems
On-Card Switching Regulators
DC Power Distribution Systems
DESCRIPTION
The AIC1577 is a current mode switching
regulator controller that drives external N-
channel power MOSFET using a fixed fre-
quency architecure. It uses external divider to
adjust output voltage from 0.8V to 20V with
excellent line and load regulation. A maximum
high duty cycle limit of 95% provides low
dropout operation which extends operating
time in battery-operated systems.
Switching frequency up to 500KHz are
achievable thus allowing smaller sized filter
components. The operating current level is
user-programmable via an external current
sense resistor. It also provide output overvolt-
age protection under fault conditions.
A multifunction pin (I_TH/RUN) allows external
compensation for optimum load step re-
sponse plus shutdown. Soft start can also be
implemented with this pin to properly se-
quence supplies. Package available are in
SOP8 and MSOP8 for SMD.
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] www.analog.com.tw
DS-1577P-02 010405
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