MAX1776 Datasheet, PDF (1/13 Pages) Maxim Integrated Products – 24V, 600mA Internal Switch, 100% Duty Cycle, Step-Down Converter

19-1975; Rev 2; 7/03
24V, 600mA Internal Switch, 100% Duty Cycle,
Step-Down Converter
General Description
The MAX1776 high-efficiency step-down converter pro-
vides an adjustable output voltage from 1.25V to V_IN from
supply voltages as high as 24V. An internal current-limit-
ed 0.4Ω MOSFET delivers load currents up to 600mA.
Operation to 100% duty cycle minimizes dropout volt-
age (240mV at 600mA).
The MAX1776 has a low 15µA quiescent current to
improve light-load efficiency and conserve battery life.
The device draws only 3µA while in shutdown.
High switching frequencies (up to 200kHz) allow the
use of tiny surface-mount inductors and output capaci-
tors. The MAX1776 is available in an 8-pin µMAX pack-
age, which uses half the space of an 8-pin SO. For
increased output drive capability, use the MAX1626/
MAX1627 step-down controllers, which drive an exter-
nal P-channel MOSFET to deliver up to 20W.
Features
o Fixed 5V or Adjustable Output
o 4.5V to 24V Input Voltage Range
o Up to 600mA Output Current
o Internal 0.4Ω P-Channel MOSFET
o Efficiency Over 95%
o 15µA Quiescent Supply Current
o 3µA Shutdown Current
o 100% Maximum Duty Cycle for Low Dropout
o Current-Limited Architecture
o Thermal Shutdown
o Small 8-µMAX Package
Applications
Notebook Computers
Distributed Power Systems
Keep-Alive Supplies
Hand-Held Devices
PART
MAX1776EUA
Ordering Information
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
8 µMAX
Typical Operating Circuit
SHDN
IN
V_IN
ILIM
LX
V_OUT
MAX1776
ILIM2
OUT
FB
GND
µMAX
TOP VIEW
Pin Configuration
FB 1
GND 2
ILIM 3
LX 4
MAX1776EUA
8 OUT
7 SHDN
6 ILIM2
5 IN
µMAX
________________________________________________________________ Maxim Integrated Products 1
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