AT1792
Preliminary Product Information
2A/18V/300KHz Step-Down Voltage Regulator
Feature
‧
4.75V to 18V Supply Voltage Operating
AT1792 is a voltage-mode PWM step-down
DC-DC converter capable of driving up to 2A
Range.
loads over a wide input supply range with excellent
‧
300KHz Fixed Switching Frequency.
line and load regulation characteristics. High
‧
Voltage-Mode PWM Step-Down Regulator. efficiency is obtained through the use of a low
‧
Built-in Power MOSFET, Rds(on)≒100mΩ. Rds(on) P-channel power switch.
‧
2A Output Current, Up to 91.9% Efficiency
It uses a fixed switching frequency up to 300KHz
‧
1.225V±1.5% Internal Reference
thus allowing smaller sized components. The
‧
Shutdown Current less than 25uA.
output voltage level is user-programmable via an
‧
Built-in Soft-Start.
external resistive voltage divider. The built-in
‧
Cycle-by-Cycle Current-Limit Protection.
soft-start can reduce inrush current on the input
‧
Short Circuitry Protection.
source at turn on.
‧
Under-Voltage Lockout Protection.
The device also has built-in cycle-by-cycle
‧
Output Voltage Adjustable up to 16V.
current-limit, under-voltage lockout and an
‧
SOP-8 Package.
ON/OFF logic-control that can power down the
regulator to a shutdown mode. In shutdown mode
Application
the regulator draws less than 20uA of supply
current. When a short circuit is detected on the
‧
Distributed Power Systems
output , the device immediately change switching
‧
Battery Charger.
frequency to 32 KHz and duty cycle is limited to
‧
Palmtop Computers, PDAs.
5% to protect IC from damage.
‧
DSL Modems
AT1792 is available in SOP-8 package.
Description
Block Diagram
EN
Regulator
Under-voltage
lockout
Current Sense
Amplifier
Current
Sense
+
-
Contol
Logic
P-MOS
VIN
SCP
OSC
32/600KHz
PWM Comparator
Error
Amplifier
-
+
1.225V
-
FB
Soft-
Start
SW
Aimtron reserves the right without notice to change this circuitry and specifications.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW:
http://www.aimtron.com.tw
11/21/2007 REV:0.5
Email:
service@aimtron.com.tw
1
+
GND
COMP
AIMTRON [ AIMTRON TECHNOLOGY ]
