AIC1579/L
Step-Down Switching Regulator Controller
FEATURES
Operation Voltage up to 15V.
Simple Voltage-Mode PWM Control.
Fast Transient Response.
2V and 1.3V
±
2% Feedback Voltage Reference
Option.
Adjustable Current Limit without External Sense
Resistors.
200KHz Free-Running Oscillator.
Short-Circuit Protection with Low Short Circuit
Output Current.
DESCRIPTION
The AIC1579 is a high-power, high-efficiency
voltage-mode switching regulator controller for
motherboard V
I/O
power supply applications.
Designed to drive an N-channel MOSFET in a
standard buck topology, the AIC1579 features a
high voltage CMOS output driver, short-circuit
protection, and 8-pin package.
An external 4-bit Digital-to-Analog Converter
(DAC) can be used along with the AIC1579 to
adjust the output voltage from 2.0V to 3.5V in
0.1V increments. Table 1 on the following page
specifies the corresponding output voltage for
16 combinations of DAC inputs as in the typical
application circuit.
The 200KHz switching frequency allows for
using
small
external
components
while
maintaining high conversion efficiency. The
11MHz bandwidth and 6V/µS slew rate of the
error
amplifier
ensures
high
converter
bandwidth and fast transient response.
The AIC1579 provides adjustable overcurrent
and short-circuit protections by sensing the
output current across the on resistance of the
external N-channel MOSFET rather than an
external low value sense resistor.
The AIC1579L provides lower reference voltage
(1.30V) than the default (2.00V, AIC1579) for
lower V
OUT
requirement.
APPLICATIONS
Power Supply for Motherboard V
GTL
(1.5V Output)
Power Supply for Motherboard V
I/O
.
High-Power 5V to 3.xV DC/DC Regulators.
Low-Voltage Distributed Power Supplies.
Analog Integrations Corporation
DS-1579-01
Nov 9, 00
4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
1
AIC [ ANALOG INTERGRATIONS CORPORATION ]
