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MAX818LCSA+T

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16
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.
________________________Applications
Battery-Powered Computers and Controllers
Embedded Controllers
Intelligent Instruments
Critical µP Monitoring
Portable Equipment
____________________________Features
♦ 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)
♦ Battery-Backup Power Switching; Battery Voltage
Can Exceed V
CC
♦ Battery Freshness Seal
♦ On-Board, 3ns Gating of Chip-Enable Signals
(MAX818)
♦ Uncommitted Voltage Monitor for Power-Fail or
Low-Battery Warning (MAX817/MAX819)
♦ Manual Reset Input (MAX819)
MAX817L/M, MAX818L/M, MAX819L/M*
+5V Microprocessor Supervisory Circuits
________________________________________________________________ Maxim Integrated Products 1
WDI
GND
PFO
PFI
1
2
8
7
BATT
RESET
V
CC
OUT
MAX817
DIP/SO/µMAX
TOP VIEW
3
4
6
5
_________________Pin Configurations
19-0486; Rev 3; 12/05
PART
†
MAX817_CPA
MAX817_CSA
MAX817_CUA 0°C to +70°C
0°C to +70°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
8 Plastic DIP
8 SO
8 µMAX
______________Ordering Information
_____________________Selector Guide
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.
Devices are available in both leaded and lead-free packaging.
Specify lead free by adding the + symbol at the end of the part
number when ordering.
SUFFIX RESET THRESHOLD (V)
L 4.65
M 4.40
FEATURE
MAX817
L/M
Active-Low Reset
✔
Backup-Battery Switchover
✔
MAX818
L/M
✔
✔
MAX819
L/M
✔
✔
Power-Fail Comparator
✔
—
Watchdog Input
✔ ✔
✔
—
Battery Freshness Seal
✔ ✔
Manual Reset Input — —
✔
✔
Chip-Enable Gating —
✔
Pin-Package
8-DIP/SO/
µMAX
8-DIP/SO/
µMAX
—
8-DIP/SO/
µMAX
Low-Power, Pin-
Compatible Upgrades for:
MAX690A/
MAX692A
—
MAX703/
MAX704
Typical Operating Circuit appears at end of data sheet.
Pin Configurations continued at end of data sheet.
*P
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.
MAX817L/M, MAX818L/M, MAX819L/M*
+5V Microprocessor Supervisory Circuits
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
CC
= +4.75V to +5.5V for MAX81_L, V
CC
= +4.5V to +5.5V for MAX81_M, V
BATT
= 2.8V, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C.)
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.
Note 1: The input voltage limits on PFI and WDI may be exceeded (up to 12V V
IN
) if the current into these pins is limited to less
than 10mA.
Input Voltage
V
CC
, BATT ..........................................................-0.3V to +6.0V
All Other Pins (Note 1).............................-0.3V to (V
CC
+ 0.3V)
Input Current
V
CC
Peak ..............................................................................1A
V
CC
Continuous .............................................................250mA
BATT Peak .....................................................................250mA
BATT Continuous .............................................................50mA
GND .................................................................................25mA
Output Current
OUT................................................................................250mA
All Other Outputs .............................................................25mA
OUT Short-Circuit Duration.................................................10sec
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) .............727mW
SO (derate 5.88mW/°C above +70°C)..........................471mW
µMAX (derate 4.10mW/°C above +70°C) .....................330mW
Operating Temperature Ranges
MAX81_ _C_A ......................................................0°C to +70°C
MAX81_ _E_A ...................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
As applicable;
CE IN = 0V,
WDI and MR unconnected
V
CC
< V
RST
I
OUT
= 50mA
I
OUT
= 5mA
V
CC
= 0V, V
OUT
= 0V
I
OUT
= 250µA, V
CC
< (V
BATT
- 0.2V)
CONDITIONS
mV40Battery Switchover Hysteresis
mV
-20
Battery Switch Threshold
(V
CC
- V
BATT
)
20
V
V
BATT -
V
BATT -
0.1 0.02
V
OUT
in Battery-Backup Mode
µA
11 60
I
SUPPLY
Supply Current (excluding I
OUT
)
11 45
V0 5.5
Operating Voltage Range, V
CC
,
V
BATT
(Note 2)
Ω100BATT to OUT On-Resistance
Ω510V
CC
to OUT On-Resistance
V
V
CC
- V
CC
-
0.5 0.25
V
OUT
Output
V
CC
- V
CC
-
0.05 0.025
µA
5.0
µA1
BATT Leakage Current,
Freshness Seal Enabled
UNITSMIN TYP MAXSYMBOLPARAMETER
V
CC
= 0V
Supply Current in Battery-
Backup Mode (excluding I
OUT
)
0.05 1.0
MAX81_ _C
MAX81_ _E
T
A
= +25°C
T
A
= T
MIN
to
T
MAX
Power-up
Power-down
T
A
= +25°C
T
A
= T
MIN
to
T
MAX
5.5V > V
CC
> (V
BATT
+ 0.2V)BATT Standby Current (Note 3)
-0.10 0.02
µA
-1.00 0.02
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +4.75V to +5.5V for MAX81_L, V
CC
= +4.5V to +5.5V for MAX81_M, V
BATT
= 2.8V, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C.)
MAX817L/M, MAX818L/M, MAX819L/M*
+5V Microprocessor Supervisory Circuits
_______________________________________________________________________________________ 3
V
PFO
= 0V
V
PFI
> 1.30V, I
SOURCE
= 40µA, V
CC
> 4.5V
MAX81_M
V
PFI
< 1.20V, I
SINK
= 3.2mA, V
CC
> 4.50V
MAX81_L
WDI = GND, time average
From V
RST
, V
CC
falling at 10V/ms
WDI = V
CC
, time average
V
CC
= 5V
MAX81_ _C, V
CC
= 1V, V
CC
falling,
V
BATT
= 0V, I
SINK
= 50µA
V
CC
> V
RST(MAX),
I
SOURCE
= 800µA
V
CC
< V
RST(MIN),
I
SINK
= 3.2mA
V
IL
= 0.4V, V
IH
= 0.8V
CC
CONDITIONS
µA250 500
PFO Short-Circuit Current
V
CC
- 1.5V
OH
PFO Output Voltage
V
0.4V
OL
nA-25 0.01 25I
PFI
PFI Input Current
mV4PFI Input Hysteresis
V1.20 1.25 1.30V
PFT
PFI Input Threshold
µA
-20 -15
WDI Input Current (Note 5)
120 160
V
3.5V
IH
WDI Input Threshold (Note 4)
0.8V
IL
ns50t
WDI
WDI Pulse Width
V
4.25 4.40 4.50
V
RST
Reset Threshold
4.50 4.65 4.75
sec1.00 1.60 2.25t
WD
Watchdog Timeout Period
µs100
V
CC
to RESET Delay
0.3
mV25Reset Threshold Hysteresis
ms140 200 280t
RP
Reset Timeout Period
V
CC
- 1.5V
OH
0.4
V
OL
UNITSMIN TYP MAXSYMBOLPARAMETER
MAX81_ _E, V
CC
= 1.2V, V
CC
falling,
V
BATT
= 0V, I
SINK
= 100µA
V
0.3
RESET Output Voltage
0.8
V
2.0
V
IL
MR Input Threshold
µs1
MR Pulse Width
V
IH
ns100
MR Pulse that Would Not Cause
a Reset
ns120
MR to Reset Delay
kΩ45 63 85
MR Pull-Up Resistance
RESET AND WATCHDOG TIMER
POWER-FAIL COMPARATOR (MAX817/MAX819 only)
MANUAL RESET INPUT (MAX819 only)
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16

MAX818LCSA+T

Mfr. #:
Buy MAX818LCSA+T
Manufacturer:
Maxim Integrated
Description:
Supervisory Circuits 5V MPU Supervisor
Lifecycle:
New from this manufacturer.
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