Maxim MAX6712M 4-pin sc70 microprocessor reset circuits with manual reset input Datasheet

19-1623; Rev 0; 1/00
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
____________________________Features
♦ Precision Monitoring of 2.5V, 3.0V, 3.3V, and 5.0V
Power-Supply Voltages
♦ Fully Specified Over Temperature
♦ Available in Three Output Configurations
Push-Pull RESET Output (MAX6711)
Push-Pull RESET Output (MAX6712)
Open-Drain RESET Output (MAX6713)
♦ 140ms min Power-On Reset Pulse Width
♦ Manual Reset Input
♦ 12µA Supply Current
♦ Guaranteed Reset Valid to VCC = +1V
♦ Power-Supply Transient Immunity
♦ No External Components
♦ 4-Pin SC70 Package
Applications
Computers
Controllers
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable/Battery-Powered Equipment
Automotive
Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
MAX6711_EXS-T
-40°C to +125°C
4 SC70-4
MAX6711_EXS-T10
-40°C to +125°C
4 SC70-4
MAX6712_EXS-T
-40°C to +125°C
4 SC70-4
MAX6712_EXS-T10
-40°C to +125°C
4 SC70-4
MAX6713_EXS-T
-40°C to +125°C
4 SC70-4
MAX6713_EXS-T10
-40°C to +125°C
4 SC70-4
Note: These parts are offered in 2.5k or 10k reels and must be
ordered in 2.5k or 10k increments. Order MAX6711_EXS-T for
2.5k reels and MAX6711_EXS-T10 for 10k reels. Insert the
desired suffix letter from the Selector Guide into the blank to
complete the part number.
Selector Guide appears at end of data sheet.
Typical Operating Circuit
Pin Configuration
TOP VIEW
VCC
VCC
VCC
GND 1
4
VCC
3
MR
RPULL-UP*
µP
MAX6711
MAX6713
RESET
PUSHBUTTON
MR
SWITCH
GND
*MAX6713 ONLY
MAX6711
MAX6712
MAX6713
RESET
INPUT
GND
RESET (RESET) 2
( ) ARE FOR MAX6712.
SC70-4
________________________________________________________________ Maxim Integrated Products
For free samples and the latest literature: www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
1
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
General Description
The MAX6711/MAX6712/MAX6713 are microprocessor
(µP) supervisory circuits used to monitor the power
supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with
+5.0V, +3.3V, +3.0V, or +2.5V-powered circuits. They
also provide a debounced manual reset input.
These circuits assert a reset signal whenever the VCC
supply voltage declines below a preset threshold or
whenever manual reset is asserted. Reset remains
asserted for at least 140ms after VCC has risen above
the reset threshold or when manual reset is deasserted.
Reset thresholds suitable for operation with a variety of
supply voltages are available.
The MAX6713 has an open-drain output stage, while
the MAX6711/MAX6712 have push-pull outputs. The
MAX6713’s open-drain RESET output requires a pull-up
resistor that can be connected to a voltage higher than
VCC. The MAX6711/MAX6713 have an active-low reset
output, while the MAX6712 has an active-high reset output. The reset comparator is designed to ignore fast
transients on VCC, and the outputs are guaranteed to
be in the correct logic state for VCC down to 1V.
Low supply current makes the MAX6711/MAX6712/
MAX6713 ideal for use in portable equipment. These
devices are available in a 4-pin SC70 package.
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
ABSOLUTE MAXIMUM RATINGS
Rate of Rise, VCC ............................................................100V/µs
Continuous Power Dissipation (TA = +70°C)
4-Pin SC70 (derate 3.1mW/°C above +70°C) ..............245mW
Operating Temperature Range .........................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Terminal Voltage (with respect to GND)
VCC ........................................................................-0.3V to +6.0V
RESET, RESET (push-pull) .........................-0.3V to (VCC + 0.3V)
RESET (open drain)...............................................-0.3V to +6.0V
MR ..............................................................-0.3V to (VCC + 0.3V)
Input Current, VCC, MR .......................................................20mA
Output Current, RESET, RESET ..........................................20mA
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 = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5V for L/M versions, VCC = +3.3V for
T/S versions, VCC = +3V for R version, VCC = +2.5V for Z version, and TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
VCC Range
CONDITIONS
ICC
TA = -40°C to +125°C
1.2
5.5
TA = +85°C to
+125°C
MAX671_M
MAX671_T
VTH
MAX671_S
MAX671_R
MAX671_Z
VCC < 5.5V, MAX671_L/M
16
35
VCC < 3.6V, MAX671_R/S/T/Z
12
30
VCC < 5.5V, MAX671_L/M
60
VCC < 3.6V, MAX671_R/S/T/Z
Reset Active Timeout Period
2
UNITS
V
µA
60
TA = +25°C
4.56
TA = -40°C to +85°C
4.50
TA = +85°C to +125°C
4.44
TA = +25°C
4.31
TA = -40°C to +85°C
4.25
TA = +85°C to +125°C
4.20
TA = +25°C
3.04
TA = -40°C to +85°C
3.00
TA = +85°C to +125°C
2.95
TA = +25°C
2.89
TA = -40°C to +85°C
2.85
TA = +85°C to +125°C
2.81
TA = +25°C
2.59
TA = -40°C to +85°C
2.55
TA = +85°C to +125°C
2.52
TA = +25°C
2.28
TA = -40°C to +85°C
2.25
2.38
TA = +85°C to +125°C
2.22
2.42
Reset Threshold Tempco
VCC to Reset Delay (Note 2)
MAX
5.5
MAX671_L
Reset Threshold
TYP
1.0
TA = -40°C to
+85°C
Supply Current
MIN
TA = 0°C to +70°C
4.63
4.70
4.75
4.82
4.38
4.45
4.50
4.56
3.08
3.11
3.15
3.21
2.93
2.96
3.00
3.05
2.63
2.66
2.70
2.74
2.32
2.35
30
VCC = VTH to (VTH - 100mV)
ppm/°C
20
TA = -40°C to +85°C
140
TA = +85°C to +125°C
100
V
240
_______________________________________________________________________________________
µs
460
640
ms
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
(VCC = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5V for L/M versions, VCC = +3.3V for
T/S versions, VCC = +3V for R version, VCC = +2.5V for Z version, and TA = +25°C.) (Note 1)
PARAMETER
RESET Output Voltage Low
(MAX6711/MAX6713)
RESET Output Voltage High
(MAX6711)
RESET Output Voltage Low
(MAX6712)
RESET Output Voltage High
(MAX6712)
SYMBOL
VOL
VOH
VOL
VOH
MIN
TYP
0.3
VCC = VTH min, ISINK = 3.2mA,
MAX6711L/M, MAX6713L/M
0.4
VCC > 1.0V, ISINK = 50µA
0.3
UNITS
V
0.8 · VCC
V
VCC > VTH max, ISOURCE = 800µA,
MAX6711L/M
0.8 · VCC
VCC = VTH max, ISINK = 1.2mA,
MAX6712R/S/T/Z
0.3
VCC = VTH max, ISINK = 3.2mA,
MAX6712L/M
0.4
V
1.8V < VCC < VTH min, ISOURCE = 150µA
0.8 · VCC
V
VCC > VTH, RESET deasserted
VIL
MAX
VCC = VTH min, ISINK = 1.2mA,
MAX6711R/S/T/Z, MAX6713R/S/T/Z
VCC > VTH max, ISOURCE = 500µA,
MAX6711R/S/T/Z
RESET Open-Drain Output
Leakage Current
MR Input Threshold
CONDITIONS
1
0.3 · VCC
0.7 · VCC
VIH
MR Pull-Up Resistance
10
MR Minimum Pulse Width
1
20
µA
V
kΩ
µs
MR Glitch Immunity
100
ns
MR to Reset Delay
200
ns
Note 1: Production testing done at TA = +25°C; limits over temperature guaranteed by design only.
Note 2: RESET output for MAX6711/MAX6713; RESET output for MAX6712.
_______________________________________________________________________________________
3
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(VCC = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5V for L/M versions, VCC = +3.3V for
T/S versions, VCC = +3V for R version, VCC = +2.5V for Z version, and TA = +25°C.)
MAX671 _Z, VCC = 2.5V
MAX671 _R/S/T, VCC = 3.3V
5
MAX671 _L/M/R/S/T/Z, VCC = 1V
0
20
40
60
80
40
VOD = 100mV
100 120
0
20
40
60
80
VOD = 20mV
90
60
VOD = 100mV
30
0
-40 -20
100 120
VOD = 200mV
0
TEMPERATURE (°C)
POWER-UP RESET TIMEOUT vs.
TEMPERATURE
MAX671_ R/S/T/Z
250
RESET THRESHOLD (V)
275
20 40 60 80
TEMPERATURE (°C)
RESET THRESHOLD vs. TEMPERATURE
1.001
MAX6711/12/13-TOC4
300
POWER-UP RESET TIMEOUT (ms)
120
VOD = 200mV
TEMPERATURE (°C)
VTH = 4.63V
1.000
0.999
225
MAX671_ L/M
200
0.998
-40 -20
0
20
40
60
TEMPERATURE (°C)
4
150
MAX6711/12/13-TOC5
-40 -20
VOD = 20mV
0
-40 -20
0
VOD = 10mV
60
20
80
100 120
-40 -20
MAX6711/12/13-TOC3
VOD = 10mV
POWER-DOWN RESET DELAY (µs)
10
180
MAX6711/12/13-TOC2
MAX671_L/M, VCC = 5V
80
POWER-DOWN RESET DELAY (µs)
MAX6711/12/13 toc01
15
MAX671_L/M
POWER-DOWN RESET DELAY vs. TEMPERATURE
MAX671_R/S/T/Z
POWER-DOWN RESET DELAY vs. TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
(NO LOAD)
SUPPLY CURRENT (µA)
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
0
20
40
60
80
100 120
TEMPERATURE (°C)
_______________________________________________________________________________________
100 120
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
PIN
NAME
1
GND
FUNCTION
VCC
Ground
RESET
(MAX6711/
MAX6713)
RESET Output remains low while VCC
is below the reset threshold, and for at
least 140ms after VCC rises above the
reset threshold.
RESET
(MAX6712)
RESET Output remains high while VCC
is below the reset threshold, and for at
least 140ms after VCC rises above the
reset threshold.
3
MR
Manual Reset Input. RESET (RESET)
remains asserted as long as MR is low,
and for at least 140ms after MR is
deasserted. This active-low input has
an internal 20kΩ (typ) pull-up resistor.
It can be driven from a TTL- or CMOSlogic line, or shorted to ground with a
switch. Leave open or connect to VCC
if unused.
4
VCC
Supply Voltage (+5.0V, +3.3V, +3.0V,
or +2.5V)
2
MAXIMUM TRANSIENT DURATION (µs)
400
TA = +25°C
320
240
160
MAX671_L/M
80
0
10
RESET
MR
GND
R1
100k
Figure 2. RESET Valid to VCC = Ground Circuit
least 140ms after VCC has risen above the reset threshold. The MAX6713 uses an open-drain output, and the
MAX6711/MAX6712 have a push-pull output stage.
Connect a pull-up resistor on the MAX6713’s RESET
output to any supply between 0 and 6V.
Manual Reset Input
Many µP-based systems require manual reset capability, allowing the operator, a test technician, or external
logic circuitry to initiate a reset. Reset remains asserted
while MR is low, and for at least 140ms after MR returns
high. This input has an internal 20kΩ pull-up resistor, so
it can be left open if it is not used. MR can be driven
with TTL- or CMOS-logic levels, or with open-drain/collector outputs. To create a manual reset function, connect a normally open momentary switch from MR to
ground; external debounce circuitry is not required. If
MR is driven from long cables or if the device is used in
a noisy environment, connecting a 0.1µF capacitor from
MR to ground provides additional noise immunity.
Applications Information
MAX671_R/S/T/Z
1
MAX6711
100
1000
RESET COMPARATOR OVERDRIVE, VTH - VCC (mV)
Figure 1. Maximum Transient Duration Without Causing a
Reset Pulse vs. Reset Comparator Overdrive
Detailed Description
Reset Output
A microprocessor’s (µP’s) reset input starts the µP in a
known state. The MAX6711/MAX6712/MAX6713 assert
reset to prevent code-execution errors during powerup, power-down, or brownout conditions. They assert a
reset signal whenever the VCC supply voltage declines
below a preset threshold, keeping it asserted for at
Negative-Going VCC Transients
In addition to issuing a reset to the µP during power-up,
power-down, and brownout conditions, the MAX6711/
MAX6712/MAX6713 are relatively immune to short-duration negative-going VCC transients (glitches).
Figure 1 shows typical transient duration vs. reset comparator overdrive, for which the MAX6711/MAX6712/
MAX6713 do not generate a reset pulse. The graph was
generated using a negative-going pulse applied to VCC,
starting 0.5V above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the maximum pulse
width a negative-going VCC transient can have without
causing a reset pulse. As the magnitude of the transient
increases (goes farther below the reset threshold), the
_______________________________________________________________________________________
5
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
_____________________Pin Description
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
+5.0V
+3.3V
VCC
VCC
VCC
VCC
VCC
RPULLUP
µP
MAX6713
RESET
MOTOROLA
RESET 68HCXX
INPUT
5V SYSTEM
MAX6713
RESET
RESET
INPUT
MR
GND
GND
Figure 3. Interfacing to µPs with Bidirectional Reset I/O
maximum allowable pulse width decreases. Typically, for
the MAX671_L and MAX671_M, a VCC transient that
goes 100mV below the reset threshold and lasts 20µs or
less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the VCC pin provides
additional transient immunity.
Ensuring a Valid Reset Output
Down to VCC = 0
When VCC falls below 1V, the MAX6711 RESET output
no longer sinks current—it becomes an open circuit.
Therefore, high-impedance CMOS-logic inputs connected to RESET can drift to undetermined voltages.
This presents no problem in most applications since
most µP and other circuitry is inoperative with V CC
below 1V. However, in applications where RESET must
be valid down to 0, adding a pull-down resistor to
RESET causes any stray leakage currents to flow to
ground, holding RESET low (Figure 2). R1’s value is not
critical; 100kΩ is large enough not to load RESET and
small enough to pull RESET to ground.
A 100kΩ pull-up resistor to VCC is also recommended
for the MAX6712 if RESET is required to remain valid for
VCC < 1V.
Interfacing to µPs with
Bidirectional Reset Pins
Since the RESET output on the MAX6713 is open-drain,
this device interfaces easily with µPs that have bidirectional reset pins, such as the Motorola 68HC11.
Connecting the µP supervisor’s RESET output directly
to the µP’s RESET pin with a single pull-up resistor
allows either device to assert reset (Figure 3).
6
GND
GND
Figure 4. MAX6713 Open-Drain RESET Output Allows Use with
Multiple Supplies
MAX6713 Open-Drain RESET Output
Allows Use with Multiple Supplies
Generally, the pull-up connected to the MAX6713 will
connect to the supply voltage that is being monitored at
the IC’s VCC pin. However, some systems may use the
open-drain output to level-shift from the monitored supply to reset circuitry powered by some other supply
(Figure 4). Note that as the MAX6713’s VCC decreases
below 1V, so does the IC’s ability to sink current at
RESET. Also, with any pull-up, RESET will be pulled
high as VCC decays toward 0. The voltage where this
occurs depends on the pull-up resistor value and the
voltage to which it is connected.
Benefits of Highly Accurate
Reset Threshold
Most µP supervisor ICs have reset threshold voltages
between 5% and 10% below the value of nominal supply voltages. This ensures a reset will not occur within
5% of the nominal supply, but will occur when the supply is 10% below nominal.
When using ICs rated at only the nominal supply ±5%,
a zone of uncertainty where the supply is between 5%
and 10% low, and where the reset may or may not be
asserted is left.
The MAX671_L/T/Z use highly accurate circuitry to
ensure that reset is asserted close to the 5% limit, and
long before the supply has declined to 10% below
nominal.
___________________Chip Information
TRANSISTOR COUNT: 380
_______________________________________________________________________________________
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
PART/SUFFIX
RESET THRESHOLD (V)
OUTPUT TYPE
MAX6711L
4.63
Push-Pull RESET
TOP MARK
AAB
MAX6711M
4.38
Push-Pull RESET
AAC
MAX6711T
3.08
Push-Pull RESET
AAD
AAE
MAX6711S
2.93
Push-Pull RESET
MAX6711R
2.63
Push-Pull RESET
AAF
MAX6711Z
2.32
Push-Pull RESET
AAG
MAX6712L
4.63
Push-Pull RESET
AAH
MAX6712M
4.38
Push-Pull RESET
AAI
MAX6712T
3.08
Push-Pull RESET
AAJ
AAK
MAX6712S
2.93
Push-Pull RESET
MAX6712R
2.63
Push-Pull RESET
AAL
MAX6712Z
2.32
Push-Pull RESET
AAM
MAX6713L
4.63
Open-Drain RESET
AAN
MAX6713M
4.38
Open-Drain RESET
AAO
MAX6713T
3.08
Open-Drain RESET
AAP
MAX6713S
2.93
Open-Drain RESET
AAQ
MAX6713R
2.63
Open-Drain RESET
AAR
MAX6713Z
2.32
Open-Drain RESET
AAS
_______________________________________________________________________________________
7
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
Selector Guide
Package Information
SC70, 4L.EPS
MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z
4-Pin SC70 Microprocessor Reset Circuits
with Manual Reset Input
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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Printed USA
is a registered trademark of Maxim Integrated Products.