
General Description
The MAX6340/MAX6421–MAX6426 low-power micro-
processor supervisor circuits monitor system voltages
from 1.6V to 5V. These devices perform a single function:
they assert a reset signal whenever the V
CC
supply volt-
age falls below its reset threshold. The reset output
remains asserted for the reset timeout period after V
CC
rises above the reset threshold. The reset timeout is exter-
nally set by a capacitor to provide more flexibility.
The MAX6421/MAX6424 have an active-low, push-
pull reset output. The MAX6422 has an active-high,
push-pull reset output and the MAX6340/MAX6423/
MAX6425/MAX6426 have an active-low, open-drain
reset output. The MAX6421/MAX6422/MAX6423 are
offered in 4-pin SC70 or SOT143 packages. The
MAX6340/MAX6424/MAX6425/MAX6426 are available
in 5-pin SOT23-5 packages.
Applications
Portable Equipment
Battery-Powered Computers/Controllers
Automotive
Medical Equipment
Intelligent Instruments
Embedded Controllers
Critical μP Monitoring
Set-Top Boxes
Computers
Features
Monitor System Voltages from 1.6V to 5V
Capacitor-Adjustable Reset Timeout Period
Low Quiescent Current (1.6μA typ)
Three RESET Output Options
Push-Pull
RESET
Push-Pull RESET
Open-Drain
RESET
Guaranteed Reset Valid to V
CC
= 1V
Immune to Short V
CC
Transients
Small 4-Pin SC70, 4-Pin SOT143, and 5-Pin SOT23
Packages
MAX6340 Pin Compatible with LP3470
MAX6424/MAX6425 Pin Compatible with
NCP300–NCP303, MC33464/MC33465,
S807/S808/S809, and RN5VD
MAX6426 Pin Compatible with PST92XX
M
Low-Power, SC70/SOT μP Reset Circuits with
Capacitor-Adjustable Reset Timeout Delay
________________________________________________________________
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
Ordering Information
GND
( ) ARE FOR THE MAX6422
V
CC
1
4
SRT
MAX6421X
MAX6422X
MAX6423X
SC70
TOP VIEW
2
3
RESET
(RESET)
Pin Configurations
19-2440; Rev 4; 12/05
Selector Guide appears at end of data sheet.
PART
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
5 SOT23-5
4 SC70-4
4 SOT143-4
4 SC70-4
4 SOT143-4
4 SC70-4
4 SOT143-4
5 SOT23-5
5 SOT23-5
5 SOT23-5
MAX6340
UK_ _-T
MAX6421
XS_ _-T
MAX6421US_ _-T
MAX6422
XS_ _-T
MAX6422US_ _-T
MAX6423
XS_ _-T
MAX6423US_ _-T
MAX6424
UK_ _-T
MAX6425
UK_ _-T
MAX6426
UK_ _-T
Note:
The MAX6340/MAX6421–MAX6426 are available with fac-
tory-trimmed reset thresholds from 1.575V to 5.0V in approxi-
mately 0.1V increments. Insert the desired nominal reset
threshold suffix (from Table 1) into the blanks. There are 50 stan-
dard versions with a required order increment of 2500 pieces.
Standard Versions Table). Required order increment is 10,000
pieces for nonstandard versions. Contact factory for availability.
All devices are available in tape-and-reel only.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing "-T" with "+T" when ordering.
Pin Configurations continued at end of data sheet.
Typical Operating Circuit appears at end of data sheet.