can be exceeded if the input current is less than 10mA.
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.
Electrical Characteristics
(V
CC
= 4.75V to 5.5V for MAX705/MAX707/MAX813L, V
CC
= 4.5V to 5.5V for MAX706/MAX708, T
A
= T
MIN
to T
MAX
, unless otherwise
noted.)
PARAMETER
Operating Voltage Range
SYMBOL
MAX70_C
V
CC
MAX813LC
MAX70_E/M, MAX813LE/M
MAX705C, MAX706C, MAX813LC
Supply Current
I
SUPPLY
MAX705E/M, MAX706E/M, MAX813LE/M
MAX707C, MAX708C
MAX707E/M, MAX708E/M
Reset Threshold (Note 2)
Reset Threshold Hysteresis (Note 2)
Reset Pulse Width (Note 2)
t
RS
I
SOURCE
= 800μA
RESET
Output Voltage
I
SINK
= 3.2mA
MAX70_C, V
CC
= 1V, I
SINK
= 50μA
MAX70_E/M, V
CC
= 1.2V, I
SINK
= 100μA
MAX707, MAX708, I
SOURCE
= 800μA
MAX707, MAX708, I
SINK
= 1.2mA
RESET Output Voltage
MAX813LC, I
SOURCE
= 4μA, V
CC
= 1.1V
MAX813LE/M, I
SOURCE
= 4μA, V
CC
= 1.2V
MAX813L
I
SOURCE
= 800μA
I
SINK
= 3.2mA
0.8
0.9
V
CC
- 1.5
0.4
V
CC
- 1.5
0.4
V
140
V
CC
- 1.5
0.4
0.3
0.3
V
V
RT
MAX705, MAX707, MAX813L
MAX706, MAX708
4.50
4.25
CONDITIONS
MIN
1.0
1.1
1.2
150
150
50
50
4.65
4.40
40
200
280
TYP
MAX
5.5
5.5
5.5
350
500
350
500
4.75
4.50
V
mV
ms
µA
V
UNITS
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Maxim Integrated
│
2
MAX705–MAX708/MAX813L
MAX705–MAX708/MAX813L
Low-Cost, μP Supervisory Circuits
Electrical Characteristics (continued)
(V
CC
= 4.75V to 5.5V for MAX705/MAX707/MAX813L, V
CC
= 4.5V to 5.5V for MAX706/MAX708, T
A
= T
MIN
to T
MAX
, unless otherwise
noted.)
PARAMETER
Watchdog Timeout Period
WDI Pulse Width
WDI Input Threshold
WDI Input Current
Low
High
SYMBOL
t
WD
t
WP
CONDITIONS
MAX705, MAX706, MAX813L
V
IL
= 0.4V, V
IH
= (V
CC
) (0.8)
MAX705, MAX706, MAX813L, V
CC
= 5V
MAX705, MAX706, MAX813L, V
CC
= 5V
MAX705, MAX706, MAX813L, WDI = 0V
MAX705, MAX706, MAX813L,
I
SOURCE
= 800μA
MAX705, MAX706, MAX813L,
I
SINK
= 1.2mA
MR
= 0V
t
MR
Low
High
t
MD
V
CC
= 5V
I
SOURCE
= 800μA
I
SINK
= 3.2mA
1.20
-25.00
V
CC
- 1.5
0.4
1.25
+0.01
2.0
250
1.30
+25.00
100
150
0.8
250
-150
V
CC
- 1.5
0.4
600
μA
ns
V
ns
V
nA
V
MIN
1.00
50
0.8
3.5
50
-50
150
TYP
1.60
MAX
2.25
UNITS
s
ns
V
µA
WDO
Output Voltage
V
MR
Pull-Up Current
MR
Pulse Width
MR
Input Threshold
MR
to Reset Out Delay (Note 2)
PFI Input Threshold
PFI Input Current
PFO
Output Voltage
Note 2:
Applies to both
RESET
in the MAX705–MAX708 and RESET in the MAX707/MAX708/MAX813L.
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Maxim Integrated
│
3
MAX705–MAX708/MAX813L
MAX705–MAX708/MAX813L
Low-Cost, μP Supervisory Circuits
Typical Operating Characteristics
MAX705/MAX707
RESET OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
T
A
= +25°C
V
CC
1V/div
+5V
V
CC
RESET
V
CC
RESET
GND
0V
500ms/div
2µs/div
2kΩ
1V/div
RESET
330pF
RESET
V
CC
V
CC
RESET
GND
10kΩ
RESET
30pF
0V
MAX705 toc01
MAX705/MAX707
RESET RESPONSE TIME
+5V
+5V
V
CC
MAX705 toc02
POWER-FAIL COMPARATOR
DE-ASSERTION RESPONSE TIME
PFI
+4V
+5V
PFO
PFO
1V/div
+1.25V
30pF
1kΩ
MAX705 toc08
V
CC
= +5V
T
A
= +25°C
+3V
+5V
0V
T
A
= +25°C
0V
+1.30V
PFI
+1.20V
400ns/div
POWER-FAIL COMPARATOR
ASSERTION RESPONSE TIME
+5V
PFO
+5V
PFI
PFO
30pF
V
CC
= +5V
T
A
= +25°C
1kΩ
MAX705 toc04
MAX707
RESET, RESET ASSERTION
V
CC
= V
RT
T
A
= +25°C
MAX705 toc05
MAX707
RESET, RESET DE-ASSERTION
V
CC
= V
RT
T
A
= +25°C
MAX705 toc06
+5V
+5V
RESET
VCC
0V
+5V
0V
RESET
RESET
GND
1V/div
0V
0V
+5V
50mV/div
10kΩ
10k
330pF
330pF
RESET
2V/div
+1.25V
+1.30V
PFI
V
CC
RESET
RESET
GND
10kΩ
10k
330pF
330pF RESET
1V/div
RESET
+1.20V 0V
400ns/div
400ns/div
400ns/div
MAX707/MAX708/MAX813L
RESET OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX705 toc07
T
A
= +25°C
V
CC
MAX813L
RESET RESPONSE TIME
+5V
+5V
V
CC
V
CC
RESET
0V
GND
1V/div
MAX705 toc08
+4V
0V
RESET
V
CC
RESET
GND
+5V
330pF 10kΩ
1V/div
330pF 10kΩ
+4V
0V
500ms/div
0V
2µs/div
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4
MAX705–MAX708/MAX813L
MAX705–MAX708/MAX813L
Low-Cost, μP Supervisory Circuits
Pin Description
PIN
MAX705/MAX706
DIP/SO
μMAX
MAX707/MAX708
DIP/SO
μMAX
MAX813L
DIP/SO
μMAX
Manual-Reset Input triggers a reset pulse when
pulled below 0.8V. This active-low input has an
internal 250μA pullup current. It can be driven from a
TTL or CMOS logic line, as well as shorted to ground
with a switch.
+5V Supply Input
0V Ground Reference for all signals
Power-Fail Voltage-Monitor Input. When PFI is less
than 1.25V,
PFO
goes low. Connect PFI to GND or
V
CC
when not used.
Power-Fail Output goes low and sinks current when
PFI is less than 1.25V; otherwise
PFO
stays high.
Watchdog Input. If WDI remains high or low for
1.6sec, the internal watchdog timer runs out and
WDO goes low (Figure 1). Floating WDI or connecting
WDI to a high-impedance three-state buffer disables
the watchdog feature. The internal watchdog timer
clears whenever reset is asserted, WDI is three
stated, or WDI sees a rising or falling edge.
No Connect
Active-Low Reset Output pulses low for 200ms when
triggered, and stays low whenever V
CC
is below the
reset threshold (4.65V in the MAX705 and 4.40V in
the MAX706). It remains low for 200ms after V
CC
rises above the reset threshold or MR goes from low
to high (Figure 3). A watchdog timeout will not trigger
RESET
unless
WDO
is connected to MR.
Watchdog Output pulls low when the internal
watchdog timer finishes its 1.6sec count and does
not go high again until the watchdog is cleared.
WDO
also goes low during low-line conditions. Whenever
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