19-0494; Rev 1; 3/96
+5 V Mic ro p ro c e s s o r S u p e rvis o ry Circ u it s
7,AX819L/M*
_______________Ge n e ra l De s c rip t io n
____________________________Fe a t u re s
The MAX817/MAX818/MAX819 microprocessor (µP)
supervisory circuits simplify power-supply monitoring,
battery control, and chip-enable gating in µP systems
b y re d uc ing the numb e r of c omp one nts re q uire d .
These devices are designed for use in +5V-powered
systems. Low supply current (11µA typical) and small
package size make these devices ideal for portable
applications. The MAX817/MAX818/MAX819 are specif-
♦ Precision Supply-Voltage Monitor:
4.65V (MAX81_L)
4.40V (MAX81_M)
♦ 11µA Quiescent Supply Current
♦ 200ms Reset Time Delay
♦ Watchdog Timer with 1.6sec Timeout
(MAX817/MAX818)
ically designed to ignore fast transients on V . Other
CC
♦ Battery-Backup Power Switching; Battery Voltage
supervisory functions include active-low reset, backup-
battery switchover, watchdog input, battery freshness
seal, and chip-enable gating. The Selector Guide below
lists the specific functions available from each device.
Can Exceed V
CC
♦ Battery Freshness Seal
♦ On-Board, 3ns Gating of Chip-Enable Signals
These devices offer two pretrimmed reset threshold volt-
ages for ±5% or ±10% power supplies: 4.65V for the L
versions and 4.40V for the M versions. The MAX817/
MAX818/MAX819 are available in space-saving µMAX
packages, as well as 8-pin DIP/SO.
(MAX818)
♦ Uncommitted Voltage Monitor for Power-Fail or
Low-Battery Warning (MAX817/MAX819)
♦ Manual Reset Input (MAX819)
______________Ord e rin g In fo rm a t io n
_____________________S e le c t o r Gu id e
†
PART
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
8 Plastic DIP
8 SO
MAX817 MAX818 MAX819
FEATURE
MAX817_CPA
MAX817_CSA
MAX817_CUA
L/M
✔
L/M
✔
L/M
✔
Active-Low Reset
8 µMAX
✔
✔
✔
Backup-Battery Switchover
Power-Fail Comparator
Watchdog Input
Ordering Information continued on last page.
✔
✔
—
✔
✔
†
These parts offer a choice of reset threshold voltage. From the
table below, select the suffix corresponding to the desired
threshold and insert it into the blank to complete the part number.
✔
—
✔
✔
✔
Battery Freshness Seal
Manual Reset Input
Chip-Enable Gating
—
—
—
✔
—
SUFFIX
RESET THRESHOLD (V)
8-DIP/SO/ 8-DIP/SO/ 8-DIP/SO/
L
4.65
4.40
Pin-Package
µMAX
µMAX
µMAX
M
Low-Power, Pin-
MAX690A/
Compatible Upgrades for: MAX692A
MAX703/
MAX704
—
_________________P in Co n fig u ra t io n s
________________________Ap p lic a t io n s
Battery-Powered Computers and Controllers
Embedded Controllers
TOP VIEW
1
2
3
4
8
7
6
5
BATT
RESET
WDI
OUT
Intelligent Instruments
V
CC
MAX817
Critical µP Monitoring
GND
PFI
Portable Equipment
PFO
DIP/SO/µMAX
Typical Operating Circuit appears at end of data sheet.
Pin Configurations continued at end of data sheet.
*Patents Pending
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800