AT1799
2A Step-Down Voltage Regulator
Feature
Description
AT1799 is a voltage-mode PWM step-down
DC-DC converter capable of driving up to 2A
loads over a wide input supply range with excellent
line and load regulation characteristics. High
efficiency is obtained through the use of a low
Rds(on) P-channel power switch.
‧ 4.75V to 16V Supply Voltage Operating
Range.
‧ 380KHz ±15% Fixed Switching Frequency.
‧ Voltage-Mode PWM Step-Down Regulator.
‧ Built-in Power MOSFET, Rds(on)≒100mΩ.
‧ 2A Output Current, Up to 91.9% Efficiency
‧ 1.215V±1.5% Internal Reference
‧ Shutdown Current less than 20uA.
‧ Thermal-Shutdown and Built-in Soft-Start.
‧ Cycle-by-Cycle Current-Limit Protection.
‧ Short Circuitry Protection.
It uses a fixed switching frequency up to 380KHz
thus allowing smaller sized components. The
output voltage level is user-programmable via an
external resistive voltage divider. The built-in
soft-start can reduce inrush current on the input
source at turn on.
‧ Under-Voltage Lockout Protection.
‧ Output Voltage Adjustable From 1.215V to
16V.
The device also has built-in cycle-by-cycle
current-limit, thermal shutdown, under-voltage
lockout and an ON/OFF logic-control that can
power down the regulator to a shutdown mode. In
shutdown mode the regulator draws less than 20uA
of supply current. When a short circuit is detected
on the output , the device immediately change
switching frequency to 42 KHz and duty cycle is
limited to 5% to protect IC from damage.
‧ SOP-8 Package.
Application
‧ Distributed Power Systems
‧ Battery Charger.
‧ Palmtop Computers, PDAs.
‧ DSL Modems
AT1799 is available in SOP-8 package.
Block Diagram
Aimtron reserves the right without notice to change this circuitry and specifications.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
8/23/2006 REV:1.1
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
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