MAX817L Datasheet, PDF (1/16 Pages) Maxim Integrated Products – +5V Microprocessor Supervisory Circuits

19-0494; Rev 1; 3/96
+5V Microprocessor Supervisory Circuits
_______________General Description
The MAX817/MAX818/MAX819 microprocessor (µP)
supervisory circuits simplify power-supply monitoring,
battery control, and chip-enable gating in µP systems
by reducing the number of components required.
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-
ically designed to ignore fast transients on V_CC. Other
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.
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.
_____________________Selector Guide
FEATURE
MAX817 MAX818 MAX819
L/M
L/M
L/M
Active-Low Reset
Backup-Battery Switchover
Power-Fail Comparator
—
Watchdog Input
—
Battery Freshness Seal
Manual Reset Input
—
—
Chip-Enable Gating
—
—
Pin-Package
8-DIP/SO/ 8-DIP/SO/ 8-DIP/SO/
µMAX µMAX µMAX
Low-Power, Pin-
MAX690A/
Compatible Upgrades for: MAX692A
—
MAX703/
MAX704
________________________Applications
Battery-Powered Computers and Controllers
Embedded Controllers
Intelligent Instruments
Critical µP Monitoring
Portable Equipment
____________________________Features
o Precision Supply-Voltage Monitor:
4.65V (MAX81_L)
4.40V (MAX81_M)
o 11µA Quiescent Supply Current
o 200ms Reset Time Delay
o Watchdog Timer with 1.6sec Timeout
(MAX817/MAX818)
o Battery-Backup Power Switching; Battery Voltage
Can Exceed V_CC
o Battery Freshness Seal
o On-Board, 3ns Gating of Chip-Enable Signals
(MAX818)
o Uncommitted Voltage Monitor for Power-Fail or
Low-Battery Warning (MAX817/MAX819)
o Manual Reset Input (MAX819)
______________Ordering Information
PART^†
TEMP. RANGE PIN-PACKAGE
MAX817_CPA
0°C to +70°C
8 Plastic DIP
MAX817_CSA
0°C to +70°C
8 SO
MAX817_CUA
0°C to +70°C
8 µMAX
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.
SUFFIX
L
M
RESET THRESHOLD (V)
4.65
4.40
_________________Pin Configurations
TOP VIEW
OUT 1
V_CC 2
GND 3
PFI 4
MAX817
8 BATT
7 RESET
6 WDI
5 PFO
Typical Operating Circuit appears at end of data sheet.
*Patents Pending
DIP/SO/µMAX
Pin Configurations continued at end of data sheet.
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