19-0496; Rev 4; 11/99
5-Pin µP Supervisory Circuits with
Watchdog and Manual Reset
________________General Description
The MAX6316–MAX6322 family of microprocessor (µP)
supervisory circuits monitors power supplies and
microprocessor activity in digital systems. It offers sev-
eral combinations of push/pull, open-drain, and bidirec-
tional (such as Motorola 68HC11) reset outputs, along
with watchdog and manual reset features. The
Selector
Guide
below lists the specific functions available from
each device. These devices are specifically designed
to ignore fast negative transients on V
CC
. Resets are
guaranteed valid for V
CC
down to 1V.
These devices are available in 26 factory-trimmed reset
threshold voltages (from 2.5V to 5V, in 100mV incre-
ments), featuring four minimum power-on reset timeout
periods (from 1ms to 1.12s), and four watchdog timeout
periods (from 6.3ms to 25.6s). Thirteen standard ver-
sions are available with an order increment requirement
of 2500 pieces (see
Standard Versions
table); contact
the factory for availability of other versions, which have
an order increment requirement of 10,000 pieces.
The MAX6316–MAX6322 are offered in a miniature
5-pin SOT23 package.
____________________________Features
o
Small 5-Pin SOT23 Package
o
Available in 26 Reset Threshold Voltages
2.5V to 5V, in 100mV Increments
o
Four Reset Timeout Periods
1ms, 20ms, 140ms, or 1.12s (min)
o
Four Watchdog Timeout Periods
6.3ms, 102ms, 1.6s, or 25.6s (typ)
o
Four Reset Output Stages
Active-High, Push/Pull
Active-Low, Push/Pull
Active-Low, Open-Drain
Active-Low, Bidirectional
o
Guaranteed Reset Valid to V
CC
= 1V
o
Immune to Short Negative V
CC
Transients
o
Low Cost
o
No External Components
MAX6316–MAX6322
_______________Ordering Information
PART
MAX6316LUK____-T
MAX6316MUK____-T
MAX6317HUK____-T
MAX6318HUK____-T
MAX6318MHUK____-T
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
5 SOT23-5
5 SOT23-5
5 SOT23-5
5 SOT23-5
5 SOT23-5
________________________Applications
Portable Computers
Computers
Controllers
Intelligent Instruments
Portable/Battery-Powered Equipment
Embedded Control Systems
Ordering Information continued at end of data sheet.
Typical Operating Circuit and Pin Configurations appear at
end of data sheet.
___________________________________________________________________Selector Guide
PART
MAX6316L
MAX6316M
MAX6317H
MAX6318LH
MAX6318MH
MAX6319LH
MAX6319MH
MAX6320P
MAX6321HP
MAX6322HP
WATCHDOG
INPUT
✔
✔
✔
✔
✔
—
—
✔
✔
—
MANUAL
RESET
INPUT
✔
✔
✔
—
—
✔
✔
✔
—
✔
RESET OUTPUTS*
ACTIVE-LOW
PUSH/PULL
✔
—
—
✔
—
✔
—
—
—
—
ACTIVE-HIGH
PUSH/PULL
—
—
✔
✔
✔
✔
✔
—
✔
✔
ACTIVE-LOW
BIDIRECTIONAL
—
✔
—
—
✔
—
✔
—
—
—
ACTIVE-LOW
OPEN-DRAIN
—
—
—
—
—
—
—
✔
✔
✔
*
The MAX6318/MAX6319/MAX6321/MAX6322 feature two types of reset output on each device.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
5-Pin µP Supervisory Circuits with
Watchdog and Manual Reset
MAX6316–MAX6322
ABSOLUTE MAXIMUM RATINGS
Voltage (with respect to GND)
V
CC
......................................................................-0.3V to +6V
RESET
(MAX6320/MAX6321/MAX6322 only)...... -0.3V to +6V
All Other Pins.........................................-0.3V to (V
CC
+ 0.3V)
Input/Output Current, All Pins .............................................20mA
Continuous Power Dissipation (T
A
= +70°C)
SOT23-5 (derate 7.1mW/°C above +70°C)...............571mW
Operating Temperature Range............................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range..............................-65°C to +160°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
(V
CC
= 2.5V to 5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Operating Voltage Range
SYMBOL
V
CC
CONDITIONS
T
A
= -40°C to +85°C
MAX6316/MAX6317/MAX6318/
MAX6320/MAX6321:
MR
and WDI unconnected
MAX6319/MAX6322:
MR
unconnected
Reset Threshold Temperature
Coefficient
Reset Threshold (Note 2)
Reset Threshold Hysteresis
MAX63_ _A_-T
Reset Active Timeout Period
t
RP
MAX63_ _B_-T
MAX63_ _C_-T
MAX63_ _D_-T
V
CC
to
RESET
Delay
t
RD
V
CC
falling at 1mV/µs
V
CC
≥
1.0V, I
SINK
= 50µA
V
OL
RESET
Output Voltage
V
OH
V
OL
RESET Output Voltage
V
OH
V
CC
≥
1.2V, I
SINK
= 100µA
V
CC
≥
2.7V, I
SINK
= 1.2mA
V
CC
≥
4.5V, I
SINK
= 3.2mA
V
CC
≥
2.7V, I
SOURCE
= 500µA
V
CC
≥
4.5V, I
SOURCE
= 800µA
V
CC
≥
2.7V, I
SINK
= 1.2mA
V
CC
≥
4.5V, I
SINK
= 3.2mA
V
CC
≥
1.8V, I
SOURCE
= 150µA
V
CC
≥
2.7V, I
SOURCE
= 500µA
V
CC
≥
4.5V, I
SOURCE
= 800µA
0.8 x V
CC
0.8 x V
CC
V
CC
- 1.5
0.8 x V
CC
V
CC
- 1.5
0.3
0.4
V
1
20
140
1120
∆V
TH
/°C
V
RST
T
A
= +25°C
T
A
= -40°C to +85°C
V
CC
= 5.5V
V
CC
= 3.6V
V
CC
= 5.5V
V
CC
= 3.6V
MIN
1
10
5
5
3
40
V
TH
-1.5% V
TH
V
TH
+1.5%
V
TH
-2.5% V
TH
V
TH
+2.5%
3
1.4
28
200
1600
40
0.3
0.3
0.3
0.4
V
2
40
280
2240
µs
ms
TYP
MAX
5.5
20
12
12
8
ppm/°C
V
mV
µA
UNITS
V
Supply Current
I
CC
PUSH/PULL RESET OUTPUT (MAX6316L/MAX6317H/MAX6318_H/MAX6319_H/MAX6321HP/MAX6322HP)
Note 1:
Over-temperature limits are guaranteed by design, not production tested.
Note 2:
A factory-trimmed voltage divider programs the nominal reset threshold (V
TH
). Factory-trimmed reset thresholds are
available in 100mV increments from 2.5V to 5V (see Table 1 at end of data sheet).
2
_______________________________________________________________________________________
5-Pin µP Supervisory Circuits with
Watchdog and Manual Reset
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 2.5V to 5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
400
333
333
666
666
0.4
4.2
0.65
20
4.7
5.2
0.3
0.3
0.3
0.4
1.0
µA
V
V
mA
kΩ
ns
MAX
UNITS
ns
BIDIRECTIONAL
RESET
OUTPUT (MAX6316M/MAX6318MH/MAX6319MH)
Transition Flip-Flop Setup Time
t
S
(Note 3)
V
CC
= 3.0V, C
L
= 120pF
RESET
Output Rise Time
(Note 4)
Active Pullup Enable Threshold
RESET
Active Pullup Current
RESET
Pullup Resistance
OPEN-DRAIN
RESET
OUTPUT (MAX6320P/MAX6321HP/MAX6322HP)
V
CC
≥
1.0V, I
SINK
= 50µA
RESET
Output Voltage
V
OL
V
CC
≥
1.2V, I
SINK
= 100µA
V
CC
≥
2.7V, I
SINK
= 1.2mA
V
CC
≥
4.5V, I
SINK
= 3.2mA
Open-Drain Reset Output
Leakage Current
I
LKG
t
R
V
CC
= 5.0V, C
L
= 200pF
V
CC
= 3.0V, C
L
= 250pF
V
CC
= 5.0V, C
L
= 400pF
V
PTH
V
CC
= 5.0V
V
CC
= 5.0V
MAX6316–MAX6322
WATCHDOG INPUT (MAX6316/MAX6317H/MAX6318_H/MAX6320P/MAX6321HP)
MAX63_ _ _ W-T
Watchdog Timeout Period
t
WD
MAX63_ _ _ X-T
MAX63_ _ _ Y-T
MAX63_ _ _ Z-T
WDI Pulse Width
WDI Input Threshold
WDI Input Current
(Note 6)
t
WDI
V
IL
V
IH
I
WDI
V
IL
= 0.3 x V
CC
, V
IH
= 0.7 x V
CC
(Note 5)
WDI = V
CC
, time average
V
WDI
= 0, time average
-20
0.8
2.0
0.3 x V
CC
0.7 x V
CC
1
100
35
V
CC
= 5V
52
230
75
µs
ns
kΩ
ns
V
4.3
71
1.12
17.9
50
0.3 x V
CC
0.7 x V
CC
120
-15
160
6.3
102
1.6
25.6
9.3
153
2.4
38.4
ms
s
ns
V
µA
MANUAL RESET INPUT (MAX6316_/MAX6317H/MAX6319_H/MAX6320P/MAX6322HP)
V
IL
MR
Input Threshold
V
IH
V
IL
V
IH
MR
Input Pulse Width
MR
Glitch Rejection
MR
Pullup Resistance
MR
to Reset Delay
Note 3:
Note 4:
Note 5:
Note 6:
V
TH
> 4.0V
V
TH
< 4.0V
This is the minimum time
RESET
must be held low by an external pulldown source to set the active pullup flip-flop.
Measured from
RESET
V
OL
to (0.8 x V
CC
), R
LOAD
=
∞.
WDI is internally serviced within the watchdog period if WDI is left unconnected.
The WDI input current is specified as the average input current when the WDI input is driven high or low. The WDI input is
designed for a three-stated-output device with a 10µA maximum leakage current and capable of driving a maximum capaci-
tive load of 200pF. The three-state device must be able to source and sink at least 200µA when active.
_______________________________________________________________________________________
3
5-Pin µP Supervisory Circuits with
Watchdog and Manual Reset
MAX6316–MAX6322
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
MAX6316/MAX6317/MAX6318/MAX6320/MAX6321
SUPPLY CURRENT vs. TEMPERATURE
MAX6316toc01
V
CC
FALLING TO RESET PROPAGATION
DELAY vs. TEMPERATURE
90
V
CC
FALLING AT 1mV/µs
V
RST
- V
CC
= 100mV
MAX6316toc02
MAX6316/MAX6317/MAX6319/MAX6320/MAX6322
MANUAL RESET TO RESET
PROPAGATION DELAY vs. TEMPERATURE
300
PROPAGATION DELAY (ns)
280
260
240
220
200
180
160
140
V
CC
= 5V
MAX6316toc03
10
9
8
SUPPLY CURRENT (µA)
7
6
5
4
3
2
1
0
-40
-20
0
20
40
60
80
V
CC
= 1V
V
CC
= 3V
V
CC
= 5V
100
RESET PROPAGATION DELAY (µs)
320
80
70
60
50
40
30
20
10
0
100
-40
-20
0
20
40
60
80
100
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
NORMALIZED RESET TIMEOUT
PERIOD vs. TEMPERATURE
MAX6316toc04
MAX6316/MAX6317/MAX6318/MAX6320/MAX6321
NORMALIZED WATCHDOG TIMEOUT
PERIOD vs. TEMPERATURE
NORMALIZED WATCHDOG TIMEOUT PERIOD
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
MAX6316toc05
1.05
NORMALIZED RESET TIMEOUT PERIOD
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
-40
-20
0
20
40
60
80
1.05
100
TEMPERATURE (°C)
MAXIMUM V
CC
TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
MAX6316toc06
MAX6316M/6318MH/6319MH
BIDIRECTIONAL
PULLUP CHARACTERISTICS
MAX6316toc07
80
RESET OCCURS ABOVE LINES
70
TRANSIENT DURATION (µs)
V
RST
= 3.3V
60
50
40
30
20
10
0
10
100
V
RST
= 4.63V
+5V
74HC05
INPUT
4.7kΩ
100pF
PASSIVE
4.7kΩ
PULLUP
2V/div
RESET, ACTIVE
PULLUP
2V/div
+5V
V
RST
= 2.63V
INPUT
74HC05
100pF
V
CC
RESET
MR GND
RESET
INPUT
5V/div
1000
200ns/div
RESET THRESHOLD OVERDRIVE (mV) V
RST
- V
CC
4
_______________________________________________________________________________________
5-Pin µP Supervisory Circuits with
Watchdog and Manual Reset
______________________________________________________________Pin Description
PIN
MAX6316L
MAX6316M
MAX6320P
MAX6318LH
MAX6318MH
MAX6321HP
MAX6319LH
MAX6319MH
MAX6322HP
NAME
FUNCTION
MAX6316–MAX6322
MAX6317H
MAX6316L/MAX6318LH/MAX6319LH:
Active-Low, Reset Output. CMOS push/pull
output (sources and sinks current).
MAX6316M/MAX6318MH/MAX6319MH:
Bidirectional, Active-Low, Reset Output.
Intended to interface directly to microprocessors
with bidirectional resets such as the Motorola
68HC11.
MAX6320P/MAX6321HP/MAX6322HP:
Open-Drain, Active-Low, Reset Output. NMOS out-
put (sinks current only). Connect a pullup resistor
from
RESET
to any supply voltage up to 6V.
—
2
1
2
3
2
3
2
RESET
GND
Active-High, Reset Output. CMOS push/pull output
(sources and sinks current). Inverse of
RESET.
Ground
Active-Low, Manual Reset Input. Pull low to force a
reset. Reset remains asserted for the duration of
the Reset Timeout Period after
MR
transitions from
low to high. Leave unconnected or connected to
V
CC
if not used.
Watchdog Input. Triggers a reset if it remains
either high or low for the duration of the watchdog
timeout period. The internal watchdog timer clears
whenever a reset asserts or whenever WDI sees a
rising or falling edge. To disable the watchdog fea-
ture, leave WDI unconnected or three-state the dri-
ver connected to WDI.
Supply Voltage. Reset is asserted when V
CC
drops below the Reset Threshold Voltage (V
RST
).
Reset remains asserted until V
CC
rises above
V
RST
and for the duration of the Reset Timeout
Period (t
RP
) once V
CC
rises above V
RST
.
1
—
1
1
RESET
3
3
—
4
MR
4
4
4
—
WDI
5
5
5
5
V
CC
_______________________________________________________________________________________
5
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