
General Description
The MAX1818 low-dropout linear regulator operates
from a +2.5V to +5.5V supply and delivers a guaran-
teed 500mA load current with low 120mV dropout. The
high-accuracy (±1%) output voltage is preset at an
internally trimmed voltage (see
Selector Guide
) or can
be adjusted from 1.25V to 5.0V with an external resis-
tive divider.
An internal PMOS pass transistor allows the low 125μA
supply current to remain independent of load, making
this device ideal for portable battery-operated equip-
ment such as personal digital assistants (PDAs), cellu-
lar phones, cordless phones, base stations, and
notebook computers.
Other features include an active-low open-drain reset
output that indicates when the output is out of regula-
tion, a 0.1μA shutdown, short-circuit protection, and
thermal shutdown protection. The device is available in
a miniature 800mW 6-pin SOT23 package.
Applications
Notebook Computers
Cellular and Cordless Telephones
Personal Digital Assistants (PDAs)
Palmtop Computers
Base Stations
USB Hubs
Docking Stations
Features
o
Guaranteed 500mA Output Current
o
Low 120mV Dropout at 500mA
o
±1% Output Voltage Accuracy
Preset at 1.5V, 1.8V, 2.0V, 2.5V, 3.3V, 5V
Adjustable from 1.25V to 5.0V
o
Power OK Output
o
Low 125μA Ground Current
o
0.1μA Shutdown Current
o
Thermal Overload Protection
o
Output Current Limit
o
Tiny 800mW 6-Pin SOT23 Package
M
500mA Low-Dropout
Linear Regulator in SOT23
________________________________________________________________
Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
19-1860; Rev 1; 3/01
Ordering Information
*Insert the desired two-digit suffix (see Selector Guide) into the
blanks to complete the part number.
Note:
The MAX1818 requires a special solder temperature
profile described in the Absolute Maximum Ratings section.
PART*
TEMP RANGE
-40
°
C to +85
°
C
PIN-PACKAGE
6 SOT23-6
MAX1818EUAT_ _
PART AND
SUFFIX
V
OUT
SOT23
TOP MARK
MAX1818EUT15
MAX1818EUT18
MAX1818EUT20
MAX1818EUT25
MAX1818EUT33
MAX1818EUT50
1.5V or Adj
1.8V or Adj
2.0V or Adj
2.5V or Adj
3.3V or Adj
5.0V or Adj
AASO
AANU
AANV
AANF
AANG
AANH
Selector Guide
Typical Operating Circuit
NC
MAX1818
IN
ON
OFF
C
IN
1
μ
F
SHDN
OUT
POK
GND
SET
C
OUT
3.3
μ
F
V
OUT
TO
μ
C
V
IN
= 2.5V TO 5.5V
R
POK
100k
Pin Configuration
POK
GND
SHDN
1
6
OUT
5
SET
IN
MAX1818
SOT23
TOP VIEW
2
3
4