MAXIM MAX700CSA

19-2690; Rev 2; 12/07
Power-Supply Monitor with Reset
The MAX700/MAX701/MAX702 are supervisory circuits
used to monitor the power supplies in microprocessor
(µP) and digital systems. The RESET/RESET outputs of
the MAX700/MAX701/MAX702 are guaranteed to be in
the correct state for VCC voltages down to +1V (Figure 4).
They provide excellent circuit reliability and low cost by
eliminating external components and adjustments when
used with +5V-powered circuits.
The MAX702 is the simplest part in the family. When
VCC falls to 4.65V, RESET goes low. The MAX702 also
provides a debounced manual reset input. The
MAX701 performs the same functions but has both
RESET and RESET outputs. Their primary function is to
provide a system reset. Accordingly, an active reset
signal is supplied for low supply voltages and for at
least 200ms after the supply voltage reaches its operating value.
In addition to the features of the MAX701 and MAX702,
the MAX700 provides preset or adjustable voltage
detection so thresholds other than 4.65V can be selected, and adjustable hysteresis. All parts are supplied in
8-pin PDIP and Narrow SO packages in commercial
and extended temperature ranges.
Applications
Features
♦ Min 200ms RESET Pulse on Power-Up, PowerDown, and During Low-Voltage Conditions
♦ Reset Threshold Factory Trimmed for +5V
Systems
♦ No External Components or Adjustments with
+5V-Powered Circuits
♦ Debounced Manual Reset Input
♦ Preset or Adjustable Voltage Detection (MAX700)
♦ Adjustable Hysteresis (MAX700)
♦ 8-Pin PDIP and Narrow SO Packages
Ordering Information
PART*
TEMP RANGE
PIN-PACKAGE
MAX700C/D
0°C to +70°C
Dice
MAX700CPA
0°C to +70°C
8 PDIP
MAX700CSA
0°C to +70°C
8 Narrow SO
MAX700EPA
-40°C to +85°C
8 PDIP
MAX700ESA
-40°C to +85°C
8 Narrow SO
MAX701C/D
0°C to +70°C
Dice
MAX701CPA
0°C to +70°C
8 PDIP
8 Narrow SO
MAX701CSA
0°C to +70°C
Computers
MAX701EPA
-40°C to +85°C
8 PDIP
Controllers
MAX701ESA
-40°C to +85°C
8 Narrow SO
Intelligent Instruments
MAX702C/D
0°C to +70°C
Automotive Systems
MAX702CPA
0°C to +70°C
8 PDIP
MAX702CSA
0°C to +70°C
8 Narrow SO
MAX702EPA
-40°C to +85°C
Critical µP Power Monitoring
Dice
8 PDIP
MAX702ESA
-40°C to +85°C
8 Narrow SO
*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.
Pin Configurations
TOP VIEW
MR 1
SENSE 2
8
VCC
MR 1
7
CTL
N.C. 2
MAX700
8
VCC
MR
1
7
N.C.
VCC
2
MAX701
8
N.C.
7
RESET
MAX702
3
6
RESET
N.C.
3
6
RESET
GND
3
6
N.C.
GND 4
5
RESET
GND 4
5
RESET
N.C. 4
5
N.C.
HYST
DIP/SO
DIP/SO
DIP/SO
________________________________________________________________ Maxim Integrated Products
1
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.
MAX700/MAX701/MAX702
General Description
MAX700/MAX701/MAX702
Power-Supply Monitor with Reset
ABSOLUTE MAXIMUM RATINGS
VCC ......................................................................-0.3V to +15.5V
Voltage (with respect to GND) at RESET, RESET,
HYST, CTL, SENSE ............................................-0.3V to VCC
Operating Temperature Range
C Suffix .............................................................0°C to +70°C
E Suffix...........................................................-40°C to +85°C
Rate of Rise, VCC ............................................................100V/µs
Power Dissipation, Any Package .....................................380mW
Storage Temperature Range .............................-55°C to +150°C
Lead Temperature (soldering, 10s)..................................+300°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.
ELECTRICAL CHARACTERISTICS
(VCC = +5V, CTL = GND on MAX700, TA = +25°C, unless otherwise noted.)
PARAMETER
CONDITIONS
VCC Monitor Voltage Range
(MAX700 Only)
TA = TMIN to TMAX, CTL = VCC
Min VCC for Valid Reset Output,
Declining Supply
TA = TMIN to TMAX, RESET ≤ 0.4V when sinking 1mA
MIN
3
TA = TMIN to TMAX
Internal Hysteresis
HYST not connected
VCC Pulse Duration Guaranteeing
15
V
100
200
Power-up
4.50
4.65
4.75
Power-down
4.50
4.62
4.75
200
350
V
30
MAX700/MAX701 only, CLOAD = 100pF
5V to 4V VCC pulse
UNITS
1
Reset Output Pulse Width
RESET Fall Time
MAX
1.5
Supply Current
Reset Threshold
TYP
Reset
10
100
0.7
MR Pullup Current
-5
ms
ns
1
10
MR Input Threshold
V
mV
500
200
No reset
µA
µs
V
-30
µA
MAX700
RESET Output Low
RESET Output High
RESET Output Low
ISINK = 3.2mA, VCC = 5V
0.4
ISINK = 1.6mA, VCC = 3V
0.4
ISOURCE = 3.2mA, VCC = 4.25V
VCC 0.4
ISOURCE = 1.6mA, VCC = 3V
VCC 0.4
ISOURCE = 0.5mA, VCC = 1.5V
VCC 0.4
0.4
ISINK = 1.6mA, VCC = 3V
0.4
ISINK = 0.4mA, VCC = 1.5V
0.4
VCC 0.4
ISOURCE = 1.6mA, VCC = 3V
VCC 0.4
RESET Output High
2
V
ISINK = 16mA, VCC = 4.25V
ISOURCE = 3.2mA, VCC = 5V
V
V
V
_______________________________________________________________________________________
Power-Supply Monitor with Reset
MAX700/MAX701/MAX702
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +5V, CTL = GND on MAX700, TA = +25°C, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
0.4
V
MAX701
RESET Output Low
ISINK = 16mA, VCC = 5V
RESET Output High
RESET Output Low
RESET Output High
ISOURCE = 3.2mA, VCC = 4.25V
VCC 0.4
ISOURCE = 1.6mA, VCC = 3V
VCC 0.4
ISOURCE = 0.5mA, VCC = 1.5V
VCC 0.4
V
ISINK = 3.2mA, VCC = 4.25V
0.4
ISINK = 1.6mA, VCC = 3V
0.4
ISINK = 0.4mA, VCC = 1.5V
0.4
ISOURCE = 3.2mA, VCC = 5V
VCC 0.4
V
V
MAX702
RESET Output Low
RESET Output High
ISINK = 3.2mA, VCC = 4.25V
0.4
ISINK = 1.6mA, VCC = 3V
0.4
ISINK = 0.4mA, VCC = 1.5V
0.4
ISOURCE = 3.2mA, VCC = 5V
VCC 0.4
V
V
MAX700 ONLY (CTL = VCC, unless otherwise noted)
SENSE Input Threshold
TA = TMIN to TMAX
1.25
1.29
1.35
V
SENSE Input Current
0.1
nA
HYST Input On-Resistance
0.5
kΩ
CTL Input Threshold
2
V
CTL Pulldown Current
30
100
µA
_______________________________________________________________________________________
3
Power-Supply Monitor with Reset
MAX700/MAX701/MAX702
Pin Description
PIN
4
NAME
MAX700
MAX701
MAX702
1
1
1
MR
2
—
—
SENSE
FUNCTION
Input for Manual Pushbutton Reset. Has internal 5µA pullup. Low input activates the
RESET/RESET outputs.
The voltage-sense input when CTL = VCC. Its threshold is 1.29V. SENSE always
remains connected to the internal comparator. So, when VCC is being monitored
internally (CTL = GND), SENSE should be left open circuit.
3
—
—
HYST
Normally NOT used when voltage is monitored through VCC (CTL = GND). When
monitoring through SENSE (CTL = VCC), HYST allows hysteresis to be added,
reducing noise and spurious reset activity (Figure 3). HYST turns on 5µs before the
RESET/RESET outputs are activated, and its on-resistance to GND is typically 1kΩ.
4
4
3
GND
Ground
5
6
7
RESET
Goes low when VCC falls below 4.65V, or when CTL = VCC on the MAX700 goes low
when SENSE falls below 1.29V.
6
5
—
RESET
Inverted Version of RESET
7
—
—
CTL
When CTL = GND, VCC is monitored by the reset circuit. When CTL = VCC, VCC is ignored
and SENSE is monitored, allowing the threshold to be set with external resistors.
8
8
2
VCC
Chip Power and +5V Sensing Input (When CTL = GND on MAX700)
—
2, 3, 7
4, 5, 6, 8
N.C.
No Connection
_______________________________________________________________________________________
Power-Supply Monitor with Reset
1MΩ
1
8
7
COMPARATOR
SENSE
2
VCC
MANUAL
RESET
BUTTON
CTL
1
150kΩ
N.C.
MAX700
RC
6
R OSC
HYST
4
RESET
MAX700
MR
SENSE
VCC
CTL
RESET
HYST
RESET
GND
8
+5V
7
6
N.C.
5
TO µP
3
5
GND
2
3
1.29V REF
R
MAX700/MAX701/MAX702
MR
RESET
4
Figure 2. MAX700 Typical Connection Diagram
Figure 1. MAX700 Block Diagram
MANUAL
RESET
BUTTON
1
R1
2
VIN
R2
MR
MAX700
VCC
SENSE
CTL
8
VIN 3V TO 15V
7
2V/div
RESET
R3
3
4
HYST
GND
RESET
RESET
6
N.C.
5
0V
TO µP
2V/div
VCC
VL
- 1 VL = LOWER VOLTAGE THRESHOLD
1.29
VTR1
R3 =
V = UPPER VOLTAGE THRESHOLD
VU - V L U
(
R1 = R2
)
0V
1s/div
HYSTERESIS = VU - VL
Figure 3. MAX700 Connected for External Senses and
Hysteresis
Figure 4 shows the RESET output of the MAX700/
MAX701/MAX702 in the correct state for VCC voltages
down to 0V. Note the effect of the built-in hysteresis on
the trigger lever of RESET.
Figure 4. Typical MAX700/MAX701/MAX702 RESET Output vs. VCC
Package Information
For the latest package outline information, go to
www.maxim-ic.com/packages.
_______________________________________________________________________________________
5
MAX700/MAX701/MAX702
Power-Supply Monitor with Reset
Revision History
REVISION
NUMBER
REVISION
DATE
0
3/90
1
11/05
Added lead-free information to the Ordering Information table.
1
2
12/07
Updated Pin Description table.
4
DESCRIPTION
Initial release
PAGES
CHANGED
—
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.
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is a registered trademark of Maxim Integrated Products, Inc.