General Description
The MAX698/MAX699 monitor the +5V supply in micro-
processor (µP) and digital systems. They supply a
RESET pulse of at least 140ms duration on power-up,
power-down, and during low-voltage brownout condi-
tions. Circuit reliability is increased at reduced cost by
eliminating all external components and adjustments.
The MAX699 includes all features of the MAX698, but
also provides a watchdog input to monitor microproces-
sor activity. The RESET output goes low if the watchdog
input (WDI) is not toggled within 1 second. The watch-
dog feature can be disabled by leaving WDI open.
Both parts are supplied in 8-lead PDIP and 16-lead
0.3in wide small outline (SO) packages and are speci-
fied from 0°C to +70°C for C grade devices and -40°C
to +85°C for E devices. The SO versions, with more
pins than the 8-lead PDIP, have additional outputs not
available in DIP packages. These are RESET (without
inversion) and watchdog output (WDO).
Applications
Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical µP Power Monitoring
Features
♦Precision Voltage Monitor
♦Power-OK/Reset Time Delay
♦Watchdog Timer
♦Minimum Component Count
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
________________________________________________________________ Maxim Integrated Products 1
19-2349; Rev 3; 12/05
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.
VCC
VCC RESET
GND
GND
GND N.C.
N.C. (WDI)*
MAX698
MAX699*
1
2
3
4
8
7
6
5
DIP
SO
VCC
VCC
RESET
RESET
GND
GND N.C.
N.C. (WDO)*
MAX698
MAX699*
1
2
3
4
16
15
14
13
N.C.
N.C.
N.C.
N.C.
N.C. GND
N.C.
N.C. (WDI)*
5
6
7
8
12
11
10
9
TOP VIEW
* PIN LABELS IN ( ) ARE FOR MAX699 ONLY
Pin Configuration
Ordering Information
MAX698
1
2
3
4
VCC
VCC
GND
GND
GND
RESET
N.C.
N.C.
8
7
6
5
+5V +5V
TO µP
RESET
INPUT
Typical Operating Circuit
PART* TEMP RANGE
PIN-PACKAGE
MAX698CPA 0°C to +70°C 8 PDIP
MAX698CWE 0°C to +70°C 16 Wide SO
MAX698EPA -40°C to +85°C 8 PDIP
MAX698EWE -40°C to +85°C 16 Wide SO
MAX699CPA 0°C to +70°C 8 PDIP
MAX699CWE 0°C to +70°C 16 Wide SO
MAX699EPA -40°C to +85°C 8 PDIP
MAX699EWE -40°C to +85°C 16 Wide SO
*Devices are available in both leaded and lead-free packag-
ing. Specify lead free by adding the + symbol at the end of the
part number when ordering.
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
2_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
VCC ........................................................................-0.3V to +6.0V
Input Voltage (with respect to GND)
WDI, WDO, RESET, RESET ..…………………………-0.3V to VCC
Operating Temperature Range
C Suffix………………………………………………0°C to +70°C
E Suffix......……………………………………….-40°C to +85°C
Rate of Rise, VCC .................………………………………100V/µs
Power Dissipation (TA= +70°C)
8-Pin PDIP (derated 5mW/°C above +70°C).....………400mW
16-Pin SO (derated 7mW/°C above +70°C) ................600mW
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(VCC = +5V, TA= +25°C, unless otherwise noted.)
PARAMETER CONDITIONS
MIN TYP MAX UNITS
Operating Voltage Range TA = full 3.0 5.5 V
Supply Current 5mA
Power-Up Reset Deassertion TA = full
4.50 4.65 4.75
V
Power-Up Reset Assertion TA = full 4.4 V
Hysteresis 40 mV
Reset Output Pulse Width
140
500 ms
Output low ISINK = 1.6mA, VCC = 4.4V 0.4
RESET OUTPUT (Open Drain) Output high ISOURCE = 1µA, VCC = 5V 3.5 V
Output low ISINK = 1.6mA, VCC = 5V 0.4
RESET OUTPUT (SO Package
Only) Output high ISOURCE = 1µA, VCC = 4.4V 3.5 V
Output low ISINK = 1.6mA, VCC = 5V 0.4
WDO Output (MAX699 SO
Package Only) Output high ISOURCE = 1µA, VCC = 4.4V 3.5 V
MAX699 Watchdog Timeout
Period
1.00
1.6
2.25
s
MAX699 Minimum WDI Input
Pulse Width
200
ns
Locic-low 0.8
MAX699 WDI Input Threshold VCC = +5V Logic-high 3.8 V
WDI = VCC 20 50
MAX699 WDI Input Current WDI = 0V -50
-15
µA
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
Pin Description
PIN
SO PDIP NAME FUNCTION
1, 4, 9 3, 4, 8 GND Chip Power Ground
2, 3 1, 2 VCC +5V Sense Input and MAX698/MAX699 Chip Power
5–8, 10–14
5, 6 N.C. No Connection
10 6 WDI (MAX699 Only)
(MAX699 Only.) A three-level input. If WDI remains high or low for
more than the watchdog timeout period, RESET pulses low (WDO
also goes low on the MAX699 SO package). If WDI is unconnected,
the watchdog circuit is disabled.
14 — WDO (MAX699 Only)
(MAX699 Only.) Goes low when WDI remains high or low for more
than the watchdog timeout period. WDO is set high at the next WDI
transition. If WDI is unconnected or at midsupply, WDO remains high.
WDO also remains high when VCC falls below 4.4V.
15 7 RESET Goes low when VCC falls below internally set threshold (see the
Electrical Characteristics table).
16 — RESET Goes high when VCC falls below internally set threshold.
WDI* WATCHDOG
TIMER
RESET
TIMER
VCC
VCC
GND
WDO*
RESET
RESET*
POWER-ON
RESET
4.65V MAX698
MAX699
*WDI ON MAX699 ONLY
RESET ON SO PACKAGE ONLY
WDO ON SO MAX699 ONLY
Figure 1. Block Diagram
_______________________________________________________________________________________ 3
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
©2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Campillo
Package Information
For the latest package outline information, go to
www.maxim-ic.com/packages.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
©2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
©2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Chip Topography
