_______________General Description
The MAX801/MAX808 microprocessor (P) supervisory
circuits monitor and control the activities of +5V Ps by
providing backup-battery switchover, low-line indica-
tion, and P reset. Additional features include a watch-
dog for the MAX801 and CMOS RAM write protection
for the MAX808.
The MAX801/MAX808 offer a choice of reset-threshold
voltage (denoted by suffix letter): 4.675V (L), 4.575V
(N), and 4.425V (M). These devices are available in
8-pin DIP and SO packages.
________________________Applications
Computers
Controllers
Intelligent Instruments
Critical P Power Monitoring
Portable/Battery-Powered Equipment
Embedded Systems
____________________________Features
o
Precision Voltage Monitoring, 1.5% Reset
Accuracy
o
200ms Power-OK/Reset Time Delay
o
RESET Output (MAX808)
RESET and RESET Outputs (MAX801)
o
Watchdog Timer (MAX801)
o
On-Board Gating of Chip-Enable Signals (MAX808):
Memory Write-Cycle Completion
3ns CE Gate Propagation Delay
o
1A Standby Current
o
Power Switching:
250mA in V
CC
Mode
20mA in Battery-Backup Mode
o
MaxCapTM/SuperCapTM Compatible
o
RESET Guaranteed Valid to V
CC
= 1V
o
Low-Line Threshold 52mV Above Reset
Threshold
MAX801L/M/N, MAX808L/M/N
8-Pin P Supervisory Circuits
with 1.5% Reset Accuracy
________________________________________________________________
Maxim Integrated Products
1
0.1
F
0.1
F
0.1
F
P
POWER
POWER FOR
CMOS RAM
NMI
BATT
V
CC
OUT
+5V
GND
RESET
FROM I/O SYSTEM OR
ADDRESS DECODER
TO CMOS RAM
CE IN
CE OUT
LOWLINE
RESET
MAX808
P SYSTEM
__________Typical Operating Circuit
19-1086; Rev 0; 6/96
PART*
MAX801
_CPA
MAX801_CSA
MAX801_EPA
-40C to +85C
0C to +70C
0C to +70C
TEMP. RANGE
PIN-PACKAGE
8 Plastic DIP
8 SO
8 Plastic DIP
______________Ordering Information
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MaxCap is a trademark of The Carborundum Corp.
SuperCap is a trademark of Baknor Industries.
Pin Configurations appear at end of data sheet.
MAX801_ESA
MAX801_MJA
MAX808
_CPA
0C to +70C
-55C to +125C
-40C to +85C
8 SO
8 CERDIP**
8 Plastic DIP
MAX808_CSA
0C to +70C
8 SO
MAX808_EPA
MAX808_ESA
MAX808_MJA
-55C to +125C
-40C to +85C
-40C to +85C
8 Plastic DIP
8 SO
8 CERDIP**
* 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.
**Contact factory for availability and processing to MIL-STD-883.
RESET THRESHOLD (V)
L
4.60
4.675
N
4.50
4.75
M
4.35
4.575
4.65
4.425
4.50
MIN
MAX
SUFFIX
TYP
MAX801L/M/N, MAX808L/M/N
8-Pin P Supervisory Circuits
with 1.5% Reset Accuracy
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
CC
= 4.6V to 5.5V for the MAX80_L, V
CC
= 4.5V to 5.5V for the MAX80_N, V
CC
= 4.35V to 5.5V for the MAX80_M; V
BATT
= 2.8V;
T
A
= T
MIN
to T
MAX
. Typical values are at V
CC
= 5V and T
A
= +25C, unless otherwise noted.)
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.
Input Voltage (with respect to GND)
V
CC
.......................................................................-0.3V to +6V
V
BATT
....................................................................-0.3V to +6V
All Other Pins........................................-0.3V to (V
OUT
+ 0.3V)
Input Current
V
CC
Peak ..........................................................................1.0A
V
CC
Continuous ............................................................500mA
I
BATT
Peak.....................................................................250mA
I
BATT
Continuous ............................................................50mA
GND ................................................................................50mA
All Other Inputs ...............................................................50mA
Output Current
OUT Peak..........................................................................1.0A
OUT Continuous............................................................500mA
All Other Outputs ............................................................50mA
Continuous Power Dissipation (T
A
= +70C)
Plastic DIP (derate 9.09mW/C above +70C) ............727mW
SO (derate 5.88mW/C above +70C) .........................471mW
CERDIP (derate 8.00mW/C above +70C) .................640mW
Operating Temperature Ranges
MAX801_C_A/MAX808_C_A...............................0C to +70C
MAX801_E_A/MAX808_E_A ............................-40C to +85C
MAX801_MJA/MAX808_MJA.........................-55C to +125C
Storage Temperature Range .............................-65C to +160C
Lead Temperature (soldering, 10sec) .............................+300C
MAX808
MAX801
V
CC
= 0V,
V
BATT
= 2.8V
CONDITIONS
A
48
90
Supply Current in Normal
Operating Mode
(excludes I
OUT
)
68
110
V
0
X
5.5
Operating Voltage Range
V
CC
, BATT (Note 1)
0.4
1
5
A
50
Supply Current in Battery-
Backup Mode (excludes
I
OUT
) (Note 2)
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
I
OUT
= 25mA
V
CC
- 0.02
I
OUT
= 250mA, MAX80_C/E
I
OUT
= 250mA, MAX80_M
V
CC
- 0.45
V
CC
= 4.5V
V
CC
- 0.38
V
CC
- 0.25
V
CC
= 3V, V
BATT
= 2.8V, I
OUT
= 100mA
1.0
1.5
V
V
CC
- 0.25
V
CC
- 0.12
V
OUT
in Normal Operating
Mode
1.8
V
CC
= 3V, I
OUT
= 100mA
1.2
2.5
V
CC
to OUT
On-Resistance
V
BATT
= 2.8V, I
OUT
= 10mA
V
BATT
- 0.25 V
BATT
- 0.12
V
BATT
= 4.5V, I
OUT
= 20mA
V
BATT
- 0.16
V
BATT
= 2.0V, I
OUT
= 5mA
V
CC
= 0V
V
V
BATT
- 0.20 V
BATT
- 0.08
V
OUT
in Battery-Backup
Mode
V
BATT
= 2.8V, I
OUT
= 10mA
12
25
V
BATT
= 4.5V, I
OUT
= 20mA
8
V
BATT
= 2.0V, I
OUT
= 5mA
V
CC
= 0V
16
40
BATT to OUT
On-Resistance
T
A
= +25C
T
A
= T
MIN
to T
MAX
MAX80_C/E
MAX80_M
T
A
= +25C
T
A
= T
MIN
to T
MAX
V
BATT
+ 0.2V
V
CC
-0.1
0.1
-1.0
1.0
A
BATT Standby Current
(Note 3)
Power-up
Power-down
V
BATT
= 2.8V
V
BATT
+ 0.05
V
BATT
V
Battery-Switchover
Threshold
50
mV
Battery-Switchover
Hysteresis
MAX80_C/E
V
CC
= 4.5V,
I
OUT
= 250mA MAX80_M
MAX801L/M/N, MAX808L/M/N
8-Pin P Supervisory Circuits
with 1.5% Reset Accuracy
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 4.6V to 5.5V for the MAX80_L, V
CC
= 4.5V to 5.5V for the MAX80_N, V
CC
= 4.35V to 5.5V for the MAX80_M; V
BATT
= 2.8V;
T
A
= T
MIN
to T
MAX
. Typical values are at V
CC
= 5V and T
A
= +25C, unless otherwise noted.)
V
CC
rising
and falling
V
CC
rising
V
CC
falling at 1mV/s
I
SINK
= 50A,
V
BATT
= 0V,
V
CC
falling
V
CC
falling at 1mV/s
MAX80_M
V
CC
falling
MAX80_L
MAX80_N
CONDITIONS
0.1
0.4
RESET Output Voltage
0.3
0.3
V
4.350
4.425
4.500
V
RST
Reset Threshold
ms
140
200
280
t
RP
RESET Active Timeout
Period
s
17
t
LL
V
CC
to
LOWLINE Delay
s
17
t
RD
V
CC
to
RESET Delay
V
4.48
4.56
V
LL
LOWLINE Threshold,
V
CC
Rising
mV
13
Reset-Threshold Hysteresis
mV
30
52
70
V
LR
LOWLINE to RESET
Threshold Voltage
4.73
4.81
4.63
4.71
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
MAX80_L
MAX80_N
4.500
4.575
4.650
4.600
4.675
4.750
MAX80_M
I
SOURCE
= 0.1mA
V
CC
- 1.5
V
CC
- 0.1
V
I
SINK
= 3.2mA
I
SOURCE
= 5mA, V
CC
= 4.25V
0.4
V
V
CC
- 1.5
RESET Output Voltage
(MAX801)
Output sink current
Output source current, V
CC
= 4.25V
I
SINK
= 3.2mA, V
CC
= 4.25V
I
SOURCE
= 5mA, V
CC
= 4.25V
0.4
V
V
CC
- 1.5
LOWLINE Output Voltage
55
mA
15
I
SC
RESET Output Short-
Circuit Current (MAX801)
Output sink current, V
CC
= 4.25V
Output source current
40
mA
20
I
SC
LOWLINE Output
Short-Circuit Current
V
CC
= 1.0V, MAX80_C
V
CC
= 1.2V, MAX80_E/M
I
SINK
= 3.2mA, V
CC
= 4.25V
Output sink current, V
CC
= 4.25V
Output source current
40
mA
1.6
I
SC
RESET Output
Short-Circuit Current
1.12
1.6
2.24
sec
0.75 x V
CC
t
WD
Watchdog Timeout Period
V
IH
V
RESET deasserted, WDI = 0V
0.8
-50
-10
V
IL
WDI Threshold Voltage
(Note 4)
A
RESET deasserted, WDI = V
CC
16
50
WDI Input Current
V
IL
= 0.8V, V
IH
= 0.75V x V
CC
100
ns
Minimum Watchdog Input
Pulse Width
RESET AND LOW-LINE
WATCHDOG TIMER (MAX801)
40
-55
-15
65
V
CC
SUPPLY CURRENT vs. TEMPERATURE
(NORMAL OPERATING MODE)
50
MAX801/808-01
TEMPERATURE (C)
V
CC
SUPPLY CURRENT (
A)
25
105
-35
45
125
5
85
70
60
45
55
75
65
MAX808
MAX801
3.0
2.5
2.0
1.5
1.0
0.5
0
-60
-20
60
140
BATTERY SUPPLY CURRENT vs.
TEMPERATURE (BATTERY-BACKUP MODE)
MAX801/808-02
TEMPERATURE (C)
BATTERY SUPPLY CURRENT (
A)
20
100
-40
40
120
0
80
6
5
4
3
2
1
0
-60
-20
60
140
MAX808
CHIP-ENABLE PROPAGATION DELAY
vs. TEMPERATURE
MAX801/808-03
TEMPERATURE (C)
PROPAGATION DELAY (ns)
20
100
-40
40
120
0
80
MAX801L/M/N, MAX808L/M/N
8-Pin P Supervisory Circuits
with 1.5% Reset Accuracy
4
_______________________________________________________________________________________
Note 1:
Either V
CC
or V
BATT
can go to 0V if the other is greater than 2V.
Note 2:
The supply current drawn by the MAX80_ from the battery (excluding I
OUT
) typically goes to 15A when (V
BATT
- 0.1V) <
V
CC
< V
BATT
. In most applications, this is a brief period as V
CC
falls through this region (see
Typical Operating
Characteristics).
Note 3:
"+" = battery-discharging current, "-" = battery-charging current.
Note 4:
WDI is internally connected to a voltage divider between V
CC
and GND. If unconnected, WDI is typically driven to 1.8V,
disabling the watchdog function.
Note 5:
The chip-enable resistance is tested with V
CE IN
= V
CC
/ 2 and I
CE IN
= 1mA.
Note 6:
The chip-enable propagation delay is measured from the 50% point at
CE IN to the 50% point at CE OUT.
Note 7:
If
CE IN goes high, CE OUT goes high immediately and stays high until reset is deasserted and CE IN is low.
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 4.6V to 5.5V for the MAX80_L, V
CC
= 4.5V to 5.5V for the MAX80_N, V
CC
= 4.35V to 5.5V for the MAX80_M; V
BATT
= 2.8V;
T
A
= T
MIN
to T
MAX
. Typical values are at V
CC
= 5V and T
A
= +25C, unless otherwise noted.)
CONDITIONS
Enabled mode, V
CC
= V
RST
(max)
75
150
CE IN to CE OUT
Resistance (Note 5)
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
V
CC
= 4.25V,
CE OUT = 0V
mA
15
CE OUT Short-Circuit
Current (
RESET Active)
V
CC
= 5V, C
LOAD
= 50pF,
50
source-impedance driver
ns
3
8
CE IN to CE OUT
Propagation Delay (Note 6)
V
CC
= 4.25V, I
OUT
= 2mA
V
3.5
CE OUT Output Voltage
High (
RESET Active)
V
CC
falling,
CE IN = 0V
s
18
RESET to CE OUT Delay
(Note 7)
V
CC
= 4.25V
0.00002
1
A
CE IN Leakage Current
V
CC
= 0V, I
OUT
= 10A
V
BATT
- 0.1
V
BATT
CHIP-ENABLE GATING (MAX808)
CHIP-ENABLE GATING (MAX808)
__________________________________________Typical Operating Characteristics
(V
CC
= 5V, V
BATT
= 2.8V, no load, T
A
= +25C, unless otherwise noted.)
MAX801L/M/N, MAX808L/M/N
8-Pin P Supervisory Circuits
with 1.5% Reset Accuracy
_______________________________________________________________________________________
5
0
50
DRIVER
2
4
6
8
0
50
100
MAX808
CHIP-ENABLE PROPAGATION DELAY
vs. CE OUT LOAD CAPACITANCE
MAX801/808-04
C
LOAD
(pF)
PROPAGATION DELAY (ns)
4.70
4.65
4.60
4.55
4.50
4.45
4.40
-60
-20
60
140
RESET THRESHOLD
vs. TEMPERATURE
MAX801/808-07
TEMPERATURE (C)
RESET THRESHOLD (V)
20
100
-40
40
120
0
80
MAX80_L
MAX80_N
MAX80_M
30
5
-60
-20
60
140
BATT
to OUT ON-RESISTANCE
vs. TEMPERATURE
10
25
MAX801/808-05
TEMPERATURE (C)
V
BATT
TO V
OUT
ON-RESISTANCE (
)
20
100
-40
40
120
0
80
20
15
V
BATT
= 2.0V
V
BATT
= 2.8V
V
BATT
= 4.5V
V
CC
= 0V
I
OUT
= 10mA
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
-60
-20
60
140
V
CC
to OUT ON-RESISTANCE
vs. TEMPERATURE
MAX801/808-06
TEMPERATURE (C)
V
CC
TO V
OUT
ON-RESISTANCE (
)
20
100
-40
40
120
0
80
I
OUT
= 250mA
280
260
240
220
200
180
160
140
-60
-20
60
140
RESET TIMEOUT PERIOD
vs. TEMPERATURE (V
CC
RISING)
MAX801/808-08
TEMPERATURE (C)
RESET TIMEOUT PERIOD (ms)
20
100
-40
40
120
0
80
0
10
20
30
40
50
60
70
80
-60
-20
60
140
LOWLINE to RESET THRESHOLD
vs. TEMPERATURE (V
CC
FALLING)
MAX801/808-09
TEMPERATURE (C)
LOWLINE TO RESET THRESHOLD (mV)
20
100
-40
40
120
0
80
____________________________Typical Operating Characteristics (continued)
(V
CC
= 5V, V
BATT
= 2.8V, no load, T
A
= +25C, unless otherwise noted.)
4.75
4.80
4.70
4.65
4.60
4.55
4.50
4.45
4.40
-60
-20
60
140
LOWLINE THRESHOLD
vs. TEMPERATURE (V
CC
RISING)
MAX801/808-10
TEMPERATURE (C)
LOWLINE THRESHOLD (V)
20
100
-40
40
120
0
80
MAX80_L
MAX80_N
MAX80_M
0
5
10
15
20
25
30
35
40
-60
-20
60
140
LOWLINE COMPARATOR PROPAGATION
DELAY vs. TEMPERATURE (V
CC
FALLING)
MAX801/808-11
TEMPERATURE (C)
PROPAGATION DELAY (
s)
20
100
-40
40
120
0
80
V
CC
FALLING AT 1mV/
s
0
5
10
15
20
25
30
35
40
-60
-20
60
140
RESET COMPARATOR PROPAGATION
DELAY vs. TEMPERATURE (V
CC
FALLING)
MAX801/808-12
TEMPERATURE (C)
PROPAGATION DELAY (
s)
20
100
-40
40
120
0
80
V
CC
FALLING AT 1mV/
s
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