MAX1818EUT25 ,500mA Low-Dropout Linear Regulator in SOT23Applicationsblanks to complete the part number.Notebook ComputersNote: The MAX1818 requires a speci ..
MAX1818EUT25#G16 ,500mA, Low-Dropout Linear Regulator in SOT23ELECTRICAL CHARACTERISTICS(V = V + 500mV or V = +2.5V, whichever is greater; SHDN = IN, T = -40°C t ..
MAX1818EUT25#TG16 ,500mA, Low-Dropout Linear Regulator in SOT23features include an active-low open-drain reset♦ Output Current Limitoutput that indicates when the ..
MAX1818EUT25+ ,500mA, Low-Dropout Linear Regulator in SOT23ApplicationsNotebook ComputersPART* TEMP RANGE PIN-PACKAGECellular and Cordless Telephones MAX1818E ..
MAX1818EUT25+T ,500mA, Low-Dropout Linear Regulator in SOT23features include an active-low open-drain reset♦ Output Current Limitoutput that indicates when the ..
MAX1818EUT25-T ,500mA, Low-Dropout Linear Regulator in SOT23MAX181819-1860; Rev 2; 6/08500mA Low-DropoutLinear Regulator in SOT23
MAX4684EUB+ ,0.5Ω/0.8Ω Low-Voltage, Dual SPDT Analog Switches in UCSPMAX4684/MAX468519-1977; Rev 4; 1/09Ω Ω Ω Ω0.5 /0.8 Low-Voltage, Dual SPDT Analog Switches in UCSP
MAX4684EUB+T ,0.5Ω/0.8Ω Low-Voltage, Dual SPDT Analog Switches in UCSPApplications Ordering InformationSpeaker Headset Switching PIN/B U M P- TOPPART TEMP RANGEMARKMP3 ..
MAX4684EUB-T ,0.5Ω/0.8Ω Low-Voltage, Dual SPDT Analog Switches in UCSPfeatures a 0.8Ω max on-♦ R Match Between ChannelsONresistance for both NO and NC switches at a +2.7 ..
MAX4684EUB-T ,0.5Ω/0.8Ω Low-Voltage, Dual SPDT Analog Switches in UCSPApplications Ordering InformationSpeaker Headset Switching PIN/B U M P- TOPPART TEMP RANGEMARKMP3 ..
MAX4685EBC+T ,0.5Ω/0.8Ω Low-Voltage, Dual SPDT Analog Switches in UCSPfeatures a 0.8Ω max on-♦ R Match Between ChannelsONresistance for both NO and NC switches at a +2.7 ..
MAX4685EUB ,0.5 /0.8 Low-Voltage / Dual SPDT Analog Switches in UCSPFeatures♦ 12-Bump, 0.5mm-Pitch UCSPThe MAX4684/MAX4685 low on-resistance (R ), low-ON♦ NC Switch Rv ..
MAX1818EUT18-MAX1818EUT25
500mA Low-Dropout Linear Regulator in SOT23
General DescriptionThe 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.
ApplicationsNotebook Computers
Cellular and Cordless Telephones
Personal Digital Assistants (PDAs)
Palmtop Computers
Base Stations
USB Hubs
Docking Stations
FeaturesGuaranteed 500mA Output CurrentLow 120mV Dropout at 500mA±1% Output Voltage Accuracy
Preset at 1.5V, 1.8V, 2.0V, 2.5V, 3.3V, 5V
Adjustable from 1.25V to 5.0VPower OK OutputLow 125µA Ground Current0.1µA Shutdown CurrentThermal Overload ProtectionOutput Current LimitTiny 800mW 6-Pin SOT23 Package
MAX1818
500mA Low-Dropout
Linear Regulator in SOT23 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.
Selector Guide
Typical Operating Circuit
Pin Configuration
Note:The MAX1818 requires a special solder temperature
profile described in the Absolute Maximum Ratings section.
MAX1818
500mA Low-Dropout
Linear Regulator in SOT23
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= VOUT+ 500mV or VIN= +2.5V, whichever is greater; SHDN= IN, TA= -40°C to +85°C, unless otherwise noted. Typical values
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
IN,SHDN,POK, SET to GND...................................-0.3V to +6V
OUT to GND................................................-0.3V to (VIN+ 0.3V)
Output Short-Circuit Duration...............................................1min
Continuous Power Dissipation (TA= +70°C) (Note 1)
6-Pin SOT23 (derate 10mW/°C above +70°C)..............800mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) (Note 2)...................+300°C
Dual Mode is a trademark of Maxim Integrated Products
Note 1:Thermal properties are specified with product mounted on PC board with one square-inch of copper area and still air. With
minimal copper, the SOT23 package dissipates 712mW at +70°C. With a quarter square inch of copper, it will dissipate
790mW at +70°C. Copper should be equally shared between the IN, OUT, and GND pins.
Note 2:This device is constructed using a unique set of packaging techniques that imposes a limit on the thermal profile to which
the device can be exposed during board-level solder attach and rework. The limit permits only the use of the solder profiles
recommended in the industry standard specification, IPC JEDEC-J-STD-020A, paragraph 7.6, Table 3 for the IR/VPR and
convection reflow. Preheating is required. Hand or wave soldering is not allowed.
MAX1818
500mA Low-Dropout
Linear Regulator in SOT23
ELECTRICAL CHARACTERISTICS (continued)(VIN= VOUT+ 500mV or VIN= +2.5V, whichever is greater; SHDN= IN, TA= -40°C to +85°C, unless otherwise noted. Typical values
Note 3:All devices are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed by
design.
Note 4:The Dropout Voltage is defined as VIN- VOUT, when VOUTis 100mV below the value of VOUTmeasured for VIN= VOUT(NOM)
+ 500mV. Since the minimum input voltage is 2.5V, this specification is only meaningful when VOUT(NOM)> 2.5V. For
VOUT(NOM)between 2.5V and 3.5V, use the following equations: Typical Dropout = -93mV/V ✕VOUT(NOM)+ 445mV;
Guaranteed Maximum Dropout = -137mV/V ✕VOUT(NOM)+7004mV. For VOUT(NOM)> 3.5V, Typical Dropout = 120mV;
Maximum Dropout = 220mV.
Typical Operating Characteristics(VIN = (VOUT+ 500mV) or +2.5V, whichever is greater; SHDN= IN, CIN= 1µF, COUT= 3.3µF, TA= +25°C, unless otherwise noted.)
MAX1818
500mA Low-Dropout
Linear Regulator in SOT23ypical Operating Characteristics (continued)(VIN = (VOUT+ 500mV) or +2.5V, whichever is greater; SHDN= IN, CIN= 1µF, COUT= 3.3µF, TA= +25°C, unless otherwise noted.)
MAX1818
500mA Low-Dropout
Linear Regulator in SOT23
SHUTDOWN WAVEFORMMAX1818 toc12
POK
SHUTDOWN
VOLTAGE
VOUT
2V/div
200µs/div
SHORT-CIRCUIT CURRENT LIMIT
vs. SUPPLY VOLTAGE
MAX1818 toc13
SUPPLY VOLTAGE (V)
SHORT-CIRCUIT CURRENT LIMIT (A)
The MAX1818 is a low-dropout, low-quiescent-current
linear regulator designed primarily for battery-powered
applications. The device supplies loads up to 500mA
and is available with preset output voltages. As illustrat-
ed in Figure 1, the MAX1818 consists of a 1.25V refer-
ence, error amplifier, P-channel pass transistor, and
internal feedback voltage-divider.
The 1.25V reference is connected to the error amplifier,
which compares this reference with the feedback volt-
age and amplifies the difference. If the feedback volt-
age is lower than the reference voltage, the
current to pass to the output and increases the output
voltage. If the feedback voltage is too high, the pass-
transistor gate is pulled up, allowing less current to
pass to the output.
The output voltage is fed back through either an inter-
nal resistive divider connected to OUT or an external
resistor network connected to SET. The Dual Mode
comparator examines VSETand selects the feedback
path. If VSETis below 50mV, the internal feedback path
is used and the output is regulated to the factory-preset
voltage.
Pin Descriptionypical Operating Characteristics (continued)(VIN = (VOUT+ 500mV) or +2.5V, whichever is greater; SHDN= IN, CIN= 1µF, COUT= 3.3µF, TA= +25°C, unless otherwise noted.)
MAX1818
500mA Low-Dropout
Linear Regulator in SOT23Additional blocks include an output current limiter, ther-
mal sensor, and shutdown logic.
Internal P-Channel Pass TransistorThe MAX1818 features a 0.25ΩP-channel MOSFET
pass transistor. Unlike similar designs using PNP pass
transistors, P-channel MOSFETs require no base drive,
which reduces quiescent current. PNP-based regula-
tors also waste considerable current in dropout when
the pass transistor saturates, and use high base-drive
currents under large loads. The MAX1818 does not suf-
fer from these problems and consumes only 125µA of
quiescent current under heavy loads as well as in
dropout.
Output Voltage SelectionThe MAX1818’s Dual Mode operation allows operation
in either a preset voltage mode or an adjustable mode.
Connect SET to GND to select the preset output volt-
age. The two-digit part number suffix identifies the out-
put voltage (see Selector Guide). For example, the
MAX1818EUT33 has a preset 3.3V output voltage.
The output voltage may also be adjusted by connecting
a voltage-divider from OUT to SET to GND (Figure 2).
Select R2 in the 25kΩto 100kΩrange. Calculate R1
with the following equation:
R1 = R2 [(VOUT/ VSET) – 1]
where VSET= 1.25V, and VOUTmay range from 1.25V
to 5.0V.
ShutdownPull SHDNlow to enter shutdown. During shutdown, the
output is disconnected from the input and supply cur-
rent drops to 0.1µA. When in shutdown, POK pulls low
and OUT is high impedance. The capacitance and load
at OUT determine the rate at which VOUTdecays.
SHDNcan be pulled as high as 6V, regardless of the
input and output voltage.
Figure 1. Functional Diagram
