Datasheet

MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +4.75V to +5.5V for MAX703, V
CC
= +4.5V to +5.5V for MAX704, V
BATT
= 2.8V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
V
IL
Low 0.8
MR Input Threshold
V
IH
High 2.0
V
MR Pulse Width t
MR
150 ns
MR to RESET Delay t
MD
250 ns
MR Pullup Current MR = 0V 100 250 600 µA
PFI Input Threshold V
CC
= 5V 1.20 1.25 1.30 V
PFI Input Current -25 +0.01 +25 nA
V
OH
I
SOURCE
= 800µA
V
CC
-
1.5
PFO Output Voltage
V
OL
I
SINK
= 3.2mA 0.4
V
Note 2: Either V
CC
or V
BATT
can go to 0V if the other is greater than 2.0V.
Note 3: “-“ = battery-charging current, “+” = battery-discharging current.
OUTPUT VOLTAGE vs. LOAD CURRENT
MAX703 toc01
I
OUT
(mA)
V
OUT
(V)
40302010
4.80
4.85
4.90
4.95
5.00
4.75
050
V
CC
= +5V
V
BATT
= +2.8V
T
A
= +25
°
C
SLOPE = 5
Ω
OUTPUT VOLTAGE vs. LOAD CURRENT
MAX703 toc02
I
OUT
(mA)
V
OUT
(V)
0.80.60.40.2
2.72
2.74
2.76
2.78
2.80
2.70
01.0
V
CC
= 0V
V
BATT
= +2.8V
T
A
= +25
°
C
SLOPE = 80
Ω
MAX703 toc03
500ms/div
MAX703 RESET OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
OV
V
CC
+5V
1V/div
+5V
1V/div
0V
V
BATT
= 0V
T
A
= +25
°
C
RESET
330pF
2kΩ
RESET
RESET
GND
V
CC
V
CC
MAX703 toc04
2μs/div
MAX703 RESET RESPONSE TIME
+5V
+5V
V
CC
1V/div
+4V
0V
T
A
= +25°C
RESET
30pF
10kΩ
RESET
RESET
GND
V
CC
V
CC
MAX703 toc05
400ns/div
POWER-FAIL COMPARATOR
RESPONSE TIME
+1.30V
+5V
+1.20V
0V
V
CC
= +5V
T
A
= +25°C
PFI
PFO
30pF
1kΩ
PFO
PFI
+5V
1.25V
MAX703 toc06
400ns/div
POWER-FAIL COMPARATOR
RESPONSE TIME
+1.20V
+1.30V
+3V
0V
PFI
PFO
30pF
PFO
1kΩ
PFI
+5V
1.25V
V
CC
= +5V
T
A
= +25
°
C
Typical Operating Characteristics
(V
CC
= +5V, V
BATT
= 2.8V, T
A
= +25°C, unless otherwise noted.)