MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
19-0130; Rev 2; 11/05
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
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General Description
The MAX703/MAX704 microprocessor (µP) supervisory
circuits reduce the complexity and number of components required for power-supply monitoring and battery
control functions in µP systems. These devices significantly improve system reliability and accuracy compared to that obtained with separate ICs or discrete
components.
The MAX703/MAX704 are available in 8-pin DIP and SO
packages and provide four functions:
1) An active-low reset during power-up, power-down,
and brownout conditions.
2) Battery-backup switching for CMOS RAM, CMOS
µPs, or other low-power logic circuitry.
3) A 1.25V threshold detector for power-fail warning,
low-battery detection, or for monitoring a power
supply other than +5V.
4) An active-low manual reset input.
The MAX703 and MAX704 differ only in their supplyvoltage monitor levels. The MAX703 generates a reset
when the supply drops below 4.65V, while the MAX704
generates a reset below 4.40V.
Features
Applications
*
Dice are tested at TA= +25°C only.
**
Contact factory for availability and processing to MIL-STD-883.
Devices in PDIP and SO packages 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. Lead free
not available for CERDIP package.
Battery-Backup Power Switching
Precision Supply-Voltage Monitor
4.65V (MAX703)
4.40V (MAX704)
200ms Reset Pulse Width
Debounced TTL/CMOS-Compatible Manual Reset
Input
200µA Quiescent Current
50nA Quiescent Current in Battery-Backup Mode
Voltage Monitor for Power-Fail or Low-Battery
Warning
8-Pin DIP and SO Packages
Guaranteed RESET Assertion to V
CC
= 1V
Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical µP Power Monitoring
MR
PFOPFI
1
2
87V
BATT
RESETV
CC
GND
V
OUT
DIP/SO
TOP VIEW
3
4
6
5
MAX703
MAX704
Pin Configuration
MAX703
MAX704
UNREGULATED DC REGULATED +5V
CMOS RAM
MICROPROCESSOR
3.6V
LITHIUM
BATTERY
R1
R2
PFI
PUSHBUTTON
SWITCH
0.1µF
V
OUT
V
BATT
V
CC
NMI
V
CC
GND
GND
GND
BUS
MR
RESET
RESET
PFO
V
CC
Typical Operating Circuit
PART TEMP RANGE PIN-PACKAGE
MAX703C/D 0°C to +70°C Dice*
MAX703CPA 0°C to +70°C 8 PDIP
MAX703CSA 0°C to +70°C 8 SO
MAX703EPA -40°C to +85°C 8 PDIP
MAX703ESA -40°C to +85°C 8 SO
MAX703MJA -55°C to +125°C 8 CERDIP**
MAX704C/D 0°C to +70°C Dice*
MAX704CPA 0°C to +70°C 8 PDIP
MAX704CSA 0°C to +70°C 8 SO
MAX704EPA -40°C to +85°C 8 PDIP
MAX704ESA -40°C to +85°C 8 SO
MAX704MJA -55°C to +125°C 8 CERDIP**
MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC= +4.75V to +5.5V for MAX703, VCC= +4.5V to +5.5V for MAX704, V
BATT
= 2.8V, TA= T
MIN
to T
MAX
, 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.
Terminal Voltage (with respect to GND)
V
CC
....................................................................-0.3V to +6.0V
V
BATT
.................................................................-0.3V to +6.0V
All Other Inputs (Note 1).........................-0.3V to (V
CB
+ 0.3V)
Input Current
V
CC
...............................................................................200mA
V
BATT
..............................................................................50mA
GND ................................................................................20mA
Output Current
V
OUT
...............................Short-Circuit Protected for Up to 10s
All Other Outputs ............................................................20mA
Rate-of-Rise V
BATT
, VCC.................................................100V/µs
Operating Temperature Range
C Suffix................................................................0°C to +70°C
E Suffix.............................................................-40°C to +85°C
M Suffix ..........................................................-55°C to +125°C
Continuous Power Dissipation (T
A
= +70°C)
8-Pin PDIP (derated 9.09mW/°C above +70°C) ..........727mW
8-Pin SO (derated 5.88mW/°C above +70°C) .............471mW
8-Pin CERDIP (derated 8.00mW/°C above +85°C) .....640mW
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: V
CB
is the greater of VCCand V
BATT
. The input voltage limits on PFI and MR may be exceeded if the current into these pins
is limited to less than 10mA.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Operating Voltage Range
, V
V
CC
BATT
Supply Current (Excluding
)
I
OUT
I
in Battery-Backup
SUPPLY
Mode (Excluding I
V
Standby Current
BATT
OUT
)
(Note 3)
V
Output
OUT
V
in Battery-Backup
OUT
Mode
Battery Switch Threshold
- V
(V
CC
BATT
)
I
SUPPLY
(Note 2) 0 5.5 V
MAX70_C 200 350
MAX70_E/M 200 500
V
= 0V, V
CC
BATT
2.8V
5.5V > VCC > V
+ 0.2V
I
= 5mA
OUT
= 50mA
I
OUT
I
= 250µA, VCC < V
OUT
V
< V
CC
RST
TA = +25°C 0.05 1.0
=
T
A
TA = +25°C -0.10 +0.02
BATT
T
A
BATT
Power-up 20
Power-down -20
Battery Switchover Hysteresis 40 mV
RESET Threshold V
RST
MAX703 4.50 4.65 4.75
MAX704 4.25 4.40 4.50
RESET Threshold Hysteresis 40 mV
RESET Pulse Width t
RESET Output Voltage
V
V
RST
OH
OL
I
I
= 800µA
SOURCE
= 3.2mA 0.4
SINK
MAX70_C, VCC = 1V, VCC falling,
V
BATT
= 0V, I
SINK
= 50µA
MAX70_E/M, VCC = 1.2V, VCC falling,
V
BATT
= 0V, I
SINK
= 100µA
= T
= T
MIN
MIN
- 0.2V
to T
to T
VCC -
0.025
VCC -
0.25
-
V
-
BATT
0.02
5.0
MAX
MAX
-1.00 +0.02
V
-
CC
0.05
V
-
CC
0.5
V
BATT
0.1
140 200 280 ms
V
-
CC
1.5
0.3
0.3
µA
µA
µA
V
V
mV
V
V
MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VCC= +4.75V to +5.5V for MAX703, VCC= +4.5V to +5.5V for MAX704, V
BATT
= 2.8V, TA= T
MIN
to T
MAX
, unless otherwise noted.)
Note 2: Either VCCor 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
VCC = +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
0 1.0
VCC = 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
TA = +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
VCC = +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
VCC = +5V
T
A
= +25°C
Typical Operating Characteristics
(VCC= +5V, V
BATT
= 2.8V, TA= +25°C, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
MR Input Threshold
MR Pulse Width t
MR to RESET Delay t
V
V
MR
MD
Low 0.8
IL
High 2.0
IH
MR Pullup Current MR = 0V 100 250 600 µA
PFI Input Threshold VCC = 5V 1.20 1.25 1.30 V
PFI Input Current -25 +0.01 +25 nA
PFO Output Voltage
V
OH
V
OL
I
I
= 800µA
SOURCE
= 3.2mA 0.4
SINK
150 ns
250 ns
-
V
CC
1.5
V
V
MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
4 _______________________________________________________________________________________
Pin Description
Figure 1. Block Diagram
Figure 2. Timing Diagram
PIN NAME FUNCTION
1V
Supply Output for CMOS RAM. When VCC is above the reset threshold, V
OUT
channel MOSFET switch. When V
is below the reset threshold, the higher of VCC or V
CC
2VCC+5V Supply Input
3 GND Ground
4 PFI
Power-Fail Comparator Input. When PFI is less than 1.25V, PFO goes low; otherwise PFO remains high. Connect
PFI to GND or V
when not used.
CC
5 PFO P ow er - Fai l C om p ar ator O utp ut. It g oes l ow and si nks cur r ent w hen P FI i s l ess than 1.25V ; other w i se P FO r em ai ns hi g h.
Manual Reset Input. Generates a reset pulse when pulled below 0.8V. This active-low input is TTL/CMOS
6 MR
compatible and can be shorted to ground with a switch. It has an internal 250µA pullup current. Leave floating
when not used.
connects to VCC through a p-
OUT
is connected to V
BATT
OUT
.
7 RESET
Reset Output. Remains low while V
It remains low for 200ms after V
Backup-Battery Input. When VCC falls below the reset threshold, V
8V
V
BATT
V
CC
MR
PFI
greater than V
BATT
repeated switching if V
BATTERY-SWITCHOVER
CIRCUITRY
1.25V
1.25V
. When VCC rises 20mV above V
CC
CC
MAX703
GND
MAX704
rises above the reset threshold (Figure 2) or MR goes from low to high.
CC
falls slowly.
RESET
GENERATOR
is below the reset threshold (4.65V for the MAX703, 4.40V for the MAX704).
CC
V
OUT
RESET
PFO
, VCC is switched to V
BATT
+5V
V
CC
V
0V
+5V
V
OUT
3.0V
0V
+5V
RESET
0V
+5V
PFO*
0V
is switched to V
BATT
RST
. The 40mV hysteresis prevents
OUT
OUT
if V
BATT
t
RST
is 20mV
V
= 3.0V
BATT
*PFO DEPENDS ON PFI EXCEPT IN BATTERY-BACKUP MODE, WHERE PFO IS LOW.
Detailed Description
RESET
Output
A µP’s reset input starts the µP in a known state.
Whenever the µP is in an unknown state, it should be
held in reset. The MAX703/MAX704 assert reset when
V
CC
is low, preventing code-execution errors during
power-up, power-down, or brownout conditions.
When V
BATT
is 2V or more, RESET is always valid, irre-
spective of VCC. On power-up, as VCCrises, RESET
remains low. When VCCexceeds the reset threshold,
an internal timer holds RESET low for a time equal to
the reset pulse width (typically 200ms); after this interval, RESET goes high (Figure 2). If a power-fail or
brownout condition occurs (i.e., VCCdrops below the
reset threshold), RESET is asserted. As long as V
CC
remains below the reset threshold, the internal timer is
continually restarted, causing the RESET output to
remain low. Thus, a brownout condition that interrupts a
previously initiated reset pulse causes an additional
200ms delay from the end of the last interruption.
Power-Fail Comparator
The PFI input is compared to an internal reference. If
PFI is less than 1.25V, PFO goes low. The power-fail
comparator can be used as an undervoltage detector
to signal a failing power supply. In the
Typical
Operating Circuit
, an external voltage-divider at PFI is
used to monitor the unregulated DC voltage from which
the regulated +5V supply is derived.
The voltage-divider can be chosen so the voltage at
PFI falls below 1.25V just before the +5V regulator
drops out. PFO is then used as an interrupt to prepare
the µP for power-down.
To conserve power, the power-fail comparator is turned
off and PFO is forced low when the MAX703/MAX704
enter battery-backup mode.
Backup-Battery Switchover
In the event of a brownout or power failure, it may be
necessary to preserve the contents of RAM. With a
backup battery installed at V
BATT
, the MAX703/
MAX704 automatically switch RAM to backup power
when VCCfails.
As long as VCCexceeds the reset threshold, VCCconnects to V
OUT
through a 5Ω p-channel MOSFET power
switch. Once VCCfalls below the reset threshold,
RESET goes low and VCCor V
BATT
(whichever is high-
er) switches to V
OUT
. Note that V
BATT
switches to V
OUT
through an 80Ω switch only if VCCis below the resetthreshold voltage and V
BATT
is greater than VCC. When
VCCexceeds the reset threshold, it is connected to the
MAX703/MAX704 substrate, regardless of the voltage
applied to V
BATT
(Figure 3). During this time, diode D1
(between V
BATT
and the substrate) conducts current
from V
BATT
to VCCif V
BATT
≥ (VCC+ 0.6V).
When the battery-backup mode is activated, V
BATT
connects to V
OUT
. In this mode, the substrate connects
to V
BATT
and internal circuitry is powered from the battery (Figure 3). Table 1 shows the status of the MAX703/
MAX704 inputs and outputs in battery-backup mode.
When VCCis below, but within, 1V of V
BATT
, the internal
switchover comparator draws about 30µA. Once V
CC
MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
_______________________________________________________________________________________ 5
Table 1. Input and Output Status in
Battery-Backup Mode
Figure 3. Battery-Switchover Block Diagram
SIGNAL STATUS
V
V
OUT
V
BATT
RESET Logic-low.
PFI Power-fail comparator is disabled.
PFO Logic-low.
MR Disabled.
VCC > Reset Threshold Open
VCC < Reset Threshold and
V
VCC < Reset Threshold and
V
Disconnected from V
CC
Connected to V
p-channel MOSFET switch.
Connected to V
< (V
V
CC
BATT
V
BATT
S1 S2
CONDITION S1/S2
> V
CC
BATT
< V
CC
BATT
.
OUT
through an internal 80Ω
BATT
. Supply current is < 1µA when
OUT
- 1V).
MAX703
MAX704
D1
SUBSTRATE
V
OUT
S3 S4
D2
D3
Open Closed
Closed Open
V
CC
S3/S4
Closed
MAX703/MAX704
drops to more than 1V below V
BATT
, the internal
switchover comparator shuts off and the supply current
falls to less than 1µA.
Manual Reset
The manual reset input (MR) allows RESET to be activated by a pushbutton switch. The switch is effectively
debounced by the 140ms minimum reset pulse width.
Because it is TTL/CMOS compatible, MR can be driven
by an external logic line.
Applications Information
Using a SuperCap®as a
Backup Power Source
SuperCaps are capacitors with extremely high capacitance values (on the order of 0.1 Farad). When using
SuperCaps, if VCCexceeds the MAX703/MAX704 reset
thresholds (4.65V and 4.40V, respectively), V
BATT
may
not exceed VCCby more than 0.6V. Thus, with a 5% tolerance on VCC, V
BATT
should not exceed VCC(min)
+ 0.6V = 5.35V. Similarly, with a 10% tolerance on VCC,
V
BATT
should not exceed 5.1V.
Figure 4’s SuperCap circuit uses the MAX703 with a
±5% tolerance voltage supply. In this circuit, the
SuperCap rapidly charges to within a diode drop of
VCC. However, the diode leakage current with tricklecharge the SuperCap voltage to VCC. If V
BATT
= 5.25V
and the power is suddenly removed and then reapplied
with VCC= 4.75V, V
BATT
- VCCdoes not exceed the
allowable 0.6V difference voltage.
Figure 5’s circuit uses the MAX704 with a ±10% tolerance voltage supply. Note that if VCC= 5.5V and
V
BATT
≤ 5.1V, the power can be suddenly removed
and reapplied with V
CC
= 4.5V, and V
BATT
- VCCwill
not exceed the allowable 0.6V voltage difference.
Batteries and Power Supplies
as Backup Power Sources
Lithium batteries work well as backup batteries
because they have very low self-discharge rates and
high-energy density. Single lithium batteries with opencircuit voltages of 3.0V to 3.6V are ideal for use with the
MAX703/MAX704. Batteries with an open-circuit voltage less than the minimum reset threshold plus 0.3V
can be directly connected to the MAX703/MAX704
V
BATT
input with no additional circuitry (see the
Typical
Operating Circuit
).
However, batteries with open-circuit voltages greater
than the reset threshold plus 0.3V CANNOT be used as
backup batteries, since they source current into the
substrate through diode D1 (Figure 3) when VCCis
close to the reset threshold.
Using the MAX703/MAX704 without a
Backup Power Source
If a backup power source is not used, ground V
BATT
and connect VCCto V
OUT
. A direct connection to V
CC
eliminates any voltage drop across the internal switch,
which would otherwise appear at V
OUT
. Alternatively,
use the MAX705–MAX708, which do not have batterybackup capabilities.
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
6 _______________________________________________________________________________________
SuperCap is a registered trademark of Bankor Industries.
Figure 4. Using a SuperCap as a Backup Power Source with a
MAX703 and a +5V ±5% Supply
Figure 5. Using a SuperCap as a Backup Power Source with
the MAX704 and a +5V ±10% Supply
Table 2. Allowable Backup-Battery Voltages
+5V
V
MAX704
GND
OUT
RESET
TO STATIC RAM
TO µP
V
CC
V
BATT
100kΩ
0.1F
PART MAXIMUM BACKUP-BATTERY VOLTAGE (V)
MAX703 4.80
MAX704 4.55
+5V
0.1F
V
MAX703
GND
OUT
RESET
TO STATIC RAM
TO µP
V
CC
V
BATT
Ensuring a Valid
RESET
Output
Down to V
CC
= 0V
When VCCfalls below 1V, the MAX703/MAX704 RESET
output no longer sinks current; it becomes an open circuit. High-impedance CMOS logic inputs can drift to
undetermined voltages if left as open circuits. If a pulldown resistor is added to the RESET pin as shown in
Figure 6, any stray charge or leakage currents will flow
to ground, holding RESET low. Resistor value R1 is not
critical. It should be about 100kΩ, which is large
enough not to load RESET and small enough to pull
RESET to ground.
Replacing the Backup Battery
The backup battery can be removed while VCCremains
valid without triggering a reset. As long as VCCstays
above the reset threshold, battery-backup mode cannot
be entered. This is an improvement on switchover ICs
that initiate a reset when V
CC
and V
BATT
are at or near
the same voltage level (regardless of the reset threshold voltage). If the voltage on the unconnected V
BATT
pin floats up toward VCC, this condition alone cannot
initiate a reset when using the MAX703/MAX704.
Adding Hysteresis to the
Power-Fail Comparator
Hysteresis adds a noise margin to the power-fail comparator and prevents repeated triggering of PFO when
VINis near the power-fail comparator trip point. Figure 7
shows how to add hysteresis to the power-fail comparator. Select the ratio of R1 and R2 so that PFI sees
1.25V when VINfalls to the desired trip point (V
TRIP
).
Resistor R3 adds hysteresis. It will typically be an order
of magnitude greater than R1 or R2. The current
through R1 and R2 should be at least 1µA to ensure
that the 25nA (max) PFI input current does not shift the
trip point. R3 should be larger than 10kΩ to prevent it
from loading down the PFO pin. Capacitor C1 adds
additional noise rejection.
Monitoring a Negative Voltage
The power-fail comparator can be used to monitor a
negative supply voltage using Figure 8’s circuit. When
the negative supply is valid, PFO is low. When the negative supply voltage droops, PFO goes high. This circuit’s accuracy is affected by the PFI threshold
tolerance, the VCCvoltage, and resistors R1 and R2.
MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
_______________________________________________________________________________________ 7
Figure 6.
RESET
Valid to Ground Circuit
Figure 7. Adding Hysteresis to the Power-Fail Comparator
Figure 8. Monitoring a Negative Voltage
V
RR
R
V
RR
RR R
TRIP
H
=
+⎛
⎝
⎜
⎞
⎠
⎟
=
+
⎛
⎝
⎜
⎞
⎠
⎟
125
125
12
2
23
12 3
.
./
||
||
V
RRR
L
−
+
−
=
125 5 125 125
132
...
5 1 25 1 25
12
−
=
−..RV
R
TRIP
V
PFI
PFO
OUT
RESET
+5V
V
CC
MAX703
MAX704
GND
R1
*OPTIONAL
R1
R2
V
IN
C1*
R3
TO µP
V
CC
MAX703
MAX704
V
BATT
+5V
R1
V
CC
PFI
R2
V-
MAX703
MAX704
PFO
GND
+5V
PFO
0V
0V V
LVTRIP
V
IN
+5V
PFO
V
H
0V
NOTE: V
IS NEGATIVE
TRIP
V
TRIP
V-
0V
MAX703/MAX704
Using the Power-Fail Comparator
to Assert Reset
In addition to asserting reset at the VCCreset threshold
voltage, reset can also be asserted at the PFI input
threshold voltage. Connect PFO to MR to initiate a reset
pulse when the monitored supply drops below a userspecified threshold or when V
CC
falls below the reset
threshold. For additional noise rejection, place a
capacitor between PFI and GND.
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
8 _______________________________________________________________________________________
Table 3. Maxim Microprocessor Supervisory Products
( m s)
NOMI NAL
WATCH-
DOG
TI MEO UT
PERI OD
( s )
0.15/0.60/
1.2
BACKUPBATTERY
SWITCH
No No No Yes No No Yes No
CE
WRITE
PROTECT
POWER- FA I L
COMPARATOR
M ANUAL
RESET
I NPUT
WATCH-
DOG
I NPUT
LOW-
LI NE
OUTPUT
ACTI VE-
HI GH
RESET
NOMI NAL
PART
MAX690A 4.65 140 1.6 Yes No Yes No No No No No
MAX691A 4.65 140/Adj. 1.6/Adj. Yes Yes Yes No Yes Yes Yes Yes
MAX692A 4.40 140 1.6 Yes No Yes No No No No No
MAX693A 4.40 140/Adj. 1.6/Adj. Yes Yes Yes No Yes Yes Yes Yes
MAX696 Adj. 35/Adj. 1.6/Adj. Yes No Yes No Yes Yes Yes Yes
MAX697 Adj. 35/Adj. 1.6/Adj. No Yes Yes No Yes Yes Yes No
MAX700 4.65/Adj. 200 — No No No Yes No No Yes No
MAX703 4.65 140 — Yes No Yes Yes No No No No
MAX704 4.40 140 — Yes No Yes Yes No No No No
MAX705 4.65 140 1.6 No No Yes Yes Yes No No No
MAX706 4.40 140 1.6 No No Yes Yes Yes No No No
MAX707 4.65 140 — No No Yes Yes No No Yes No
MAX708 4.40 140 — No No Yes Yes No No Yes No
MAX791 4.65 140 1.0 Yes Yes Yes Yes Yes Yes Yes Yes
MAX1232 4.50/4.75 250
MAX1259 — — — Yes No Yes No No No No No
RESET
THRESHOLD
( V)
M I NI M UM
RESET
PULSE
WI DTH
BATT
ON
OUTPUT
MAX703/MAX704
Low-Cost Microprocessor Supervisory
Circuits with Battery Backup
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________
9
© 2005 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
REDUTA
Package Information
For the latest package outline information, go to
www.maxim-ic.com/packages
.
Chip Topography
SUBSTRATE MUST BE LEFT UNCONNECTED
TRANSISTOR COUNT: 573
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