19-1568; Rev 2; 12/05
6-Pin µP Reset Circuit with
Power-Fail Comparator
General Description
Features
The MAX6342–MAX6345 family of microprocessor (µP)
supervisory circuits monitors power supplies in digital sys-
tems. These devices significantly improve system reliabili-
ty and accuracy compared to separate ICs or discrete
components.
♦ Small 6-Pin SOT23 Package
♦ Precision Factory-Set V Reset Thresholds
CC
Between 2.33V and 4.63V
♦ Guaranteed RESET Valid to V
= +1V
CC
The MAX6342–MAX6345 provide factory-trimmed V
CC
♦ 100ms min Reset Pulse Width
reset threshold voltages from 2.33V to 4.63V and operate
with supply voltages between +1V and +5.5V. A +1.25V
threshold detector allows for a power-fail warning, for
low-battery detection, or for monitoring another power
supply. The MAX6342 contains an MR input and an
active-low push-pull reset. The MAX6343 and MAX6344
are identical to the MAX6342 except they provide an
active-low, open-drain reset and an active-high, push-
pull reset, respectively. The MAX6345 provides a second
reset output in place of the MR input to give it an active-
high push-pull reset and an active-low push-pull reset.
♦ Debounced CMOS-Compatible Manual-Reset
Input
♦ Voltage Monitor for Power-Fail or Low-Battery
Warning
Ordering Information
PART
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
MAX6342_UT-T
MAX6343_UT-T
MAX6344_UT-T
MAX6345_UT-T
All of the devices are packaged in a miniature 6-pin
SOT23.
Note: The MAX6342–MAX6345 are available with factory-set
reset thresholds from 2.33V to 4.63V (see Selector Guides 1, 2).
Insert the letter corresponding to the desired nominal reset
threshold into the blank following the part number. There is a
2500 piece order increment required for the SOT package. SOT
Top Marks table appears at end of data sheet.
Applications
Portable Computers
Telecom Equipment
Networking Equipment
Portable/Battery-Powered Equipment
Multivoltage Systems
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
Pin Configurations
Embedded Control Systems
Typical Operating Circuit appears at end of data sheet.
TOP VIEW
Selector Guide 1
RESET THRESHOLD (V)
V
1
2
3
6
5
4
RESET (RESET)
CC
SUFFIX
MAX6342
MAX6343
MAX6344
4.63
4.38
3.08
2.93
2.63
2.33
L
M
T
GND
PFI
MR
PFO
S
R
Z
( ) ARE FOR MAX6344 ONLY.
SOT23-6
Pin Configurations continued at end of data sheet.
Selector Guide 2
PUSH-PULL
RESET OUTPUT
OPEN-DRAIN
RESET OUTPUT
PUSH-PULL RESET
OUTPUT
MANUAL-RESET
INPUT
PART
✔
✔
✔
✔
—
MAX6342
MAX6343
MAX6344
MAX6345
—
—
—
✔
✔
✔
—
—
✔
—
—
________________________________________________________________ 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.