19-2532; Rev 1; 10/02
300mA LDO Linear Regulators with
Internal Microprocessor Reset Circuit
General Description
Features
o 3 ✕ 3 UCSP, 6-Pin SOT23, and 8-Pin QFN Packages
o Preset +1.5V to +3.3V Output (100mV Increments)
o SET Pin for Adjustable Output Voltage
The MAX6469–MAX6484 are low-dropout linear regula-
tors with a fully integrated microprocessor reset circuit.
Each is available with preset output voltages from +1.5V
to +3.3V in 100mV increments and delivers up to 300mA
of load current. These devices consume only 82µA of
supply current. The low supply current, low dropout volt-
age, and integrated reset functionality make these
devices ideal for battery-powered portable equipment.
o 75µV
LDO Output Voltage Noise
RMS
(MAX6477–MAX6484)
o
2.0ꢀ Accuracꢁ Oꢂer Temperature
o Guaranteed 300mA Output Current
The MAX6469–MAX6484 include a reset output that indi-
cates when the regulator output drops below standard
microprocessor supply tolerances (-7.5% or -12.5% of
nominal output voltage). This eliminates the need for an
external microprocessor supervisor, while ensuring that
supply voltages and clock oscillators have stabilized
before processor activity is enabled. Push-pull and open-
drain active-low reset outputs are available, with reset
timeout periods of 2.5ms, 20ms, 150ms, or 1200ms (min).
o Low Dropout Voltage
55mV at 150mA
114mV at 300mA
o 82µA Supplꢁ Current, 0.1µA Shutdown Current
o Input Reꢂerse Current, Thermal and Short-Circuit
Protection
o Microprocessor Reset with Four Timeout Options
o Push-Pull or Open-Drain RESET
o Manual Reset Input
The MAX6469/MAX6470/MAX6473–MAX6478/MAX6481–
MAX6484 also have a shutdown feature that reduces the
supply current to 0.1µA (typ). The MAX6471–MAX6474/
MAX6479–MAX6482 offer a manual reset input to assert a
microprocessor reset while the regulator output is within
specification. The MAX6475/MAX6476/MAX6483/
MAX6484 feature a remote feedback sense pin for use
with an external NPN transistor for higher-current applica-
tions. The MAX6469–MAX6476 are available in 6-pin
SOT23 and 8-pin thin QFN packages. The MAX6477–
MAX6484 are available in a 3 × 3 chip-scale package
(UCSP™). All devices are specified for operation from
-40°C to +85°C.
o Remote Feedback Sense
Ordering Information
PIN-
PACKAGE
PART
TEMP RANGE
MAX6469UT_ _ _D_-T
MAX6469TA_ _ _D_*
MAX6470UT_ _ _D_-T
MAX6470TA_ _ _D_*
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
6 SOT23-6
8 Thin QFN
6 SOT23-6
8 Thin QFN
*Future product—contact factory for availability.
Applications
Hand-Held Instruments (PDAs, Palmtops)
PCMCIA Cards/USB Devices
Cellular/Cordless Telephones
CD/DVD Drives
Note: The first “_ _ are placeholders for the output voltage levels
”
of the devices. Desired output voltages are set by the suffix found
in the Output Voltage Suffix Guide (Table 1). The third “_” is a
placeholder for the reset threshold accuracy. Desired reset
threshold accuracy is set by the suffix found in the Reset
Threshold Accuracy Guide (Table 2). The “_” following the D is a
placeholder for the reset timeout delay time. Desired reset timeout
delay time is set by the suffix found in the Reset Timeout Delay
Guide (Table 3). For example, the MAX6481BL30BD4-T has a
3.0V output voltage, 12.5% reset threshold tolerance, and a
1200ms (min) reset timeout delay. Sample stock is generally avail-
able on standard versions only (Table 4). Standard versions
require a minimum order increment of 2.5k units. Nonstandard
versions must be ordered in 10k-unit increments. Contact factory
for availability.
Notebook Computers
Digital Cameras
Bluetooth Modules/Wireless LAN
UCSP is a trademark of Maxim Integrated Products, Inc.
Ordering Information continued at end of data sheet.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
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.