MAX6746–MAX6753
µP Reset Circuits with Capacitor-Adjustable
Reset/Watchdog Timeout Delay
General Description
Features
The MAX6746–MAX6753 low-power microprocessor
(µP) supervisory circuits monitor single/dual system
supply voltages from 1.575V to 5V and provide maxi-
mum adjustability for reset and watchdog functions.
o Factory-Set Reset Threshold Options from 1.575V
to 5V in ~100mV Increments
o Adjustable Reset Threshold Options
o Single/Dual Voltage Monitoring
These devices assert a reset signal whenever the V
CC
supply voltage or RESET IN falls below its reset thresh-
old or when manual reset is pulled low. The reset output
o Capacitor-Adjustable Reset Timeout
o Capacitor-Adjustable Watchdog Timeout
o Min/Max (Windowed) Watchdog Option
o Manual Reset Input Option
remains asserted for the reset timeout period after V
CC
and RESET IN rise above the reset threshold. The reset
function features immunity to power-supply transients.
The MAX6746–MAX6753 have ±±2 factory-trimmed
reset threshold voltages in approximately 100mV incre-
ments from 1.575V to 5.0V and/or adjustable reset
threshold voltages using external resistors.
o Guaranteed RESET Valid for V
o 3.7µA Supply Current
≥ 1V
CC
o Push-Pull or Open-Drain RESET Output Options
o Power-Supply Transient Immunity
o Small 8-Pin SOT23 Packages
The reset and watchdog delays are adjustable with
external capacitors. The MAX6746–MAX6751 contain a
watchdog select input that extends the watchdog time-
out period by 1±8x. The MAX675±/MAX6753 contain a
window watchdog timer that looks for activity outside an
expected window of operation.
Ordering Information
PART
TEMP RANGE
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
-40°C to +1±5°C
PIN-PACKAGE
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
8 SOT±3
MAX6746KA_ _-T
MAX6746KA_ _/V+T
MAX6747KA_ _-T
MAX6747KA_ _/V+T
MAX6748KA-T
The MAX6746–MAX6753 are available with a push-pull
or open-drain active-low RESET output. The MAX6746–
MAX6753 are available in an 8-pin SOT±3 package and
are fully specified over the automotive temperature
range (-40°C to +1±5°C).
MAX6749KA-T
Applications
MAX6750KA_ _-T
MAX6750KA_ __/V+T
MAX6751KA_ _-T
MAX6751KA_ _/V+T*
MAX6752KA_ _-T
MAX6753KA_ _-T
MAX6753KA_ _/V+T
Medical Equipment
Automotive
Embedded Controllers
Critical µP Monitoring
Set-Top Boxes
Intelligent Instruments
Portable Equipment
Computers
Battery-Powered
Computers/Controllers
Note: “_ _” represents the two number suffix needed when
ordering the reset threshold voltage value for the
Pin Configurations
MAX6746/MAX6747 and MAX6750–MAX6753. The reset
threshold voltages are available in approximately 100mV incre-
ments. Table ± contains the suffix and reset factory-trimmed
voltages. All devices are available in tape-and-reel only. There
is a ±500-piece minimum order increment for standard ver-
sions (see Table 3). Sample stock is typically held on standard
versions only. Nonstandard versions require a minimum order
increment of 10,000 pieces. Contact factory for availability.
TOP VIEW
+
RESET IN (MR)
SWT
1
2
3
4
8
7
6
5
V
CC
RESET
WDI
MAX6746–
MAX6751
SRT
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
GND
WDS
+ Denotes a lead (Pb)-Free/RoHs-compliant package.
T = Tape and reel
/V denotes an automotive qualified part.
*Future product—contact factory for availability.
SOT23
( ) ARE FOR MAX6746 AND MAX6747 ONLY.
Selector Guide appears at end of data sheet.
Typical Operating Circuit appears at end of data sheet.
Pin Configurations continued at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-±530; Rev 8; ±/14