19-0243; Rev 1; 9/94
3.0V/3.3V Microprocessor Supervisory Circuits
_______________General Description
These microprocessor (µP) supervisory circuits reduce
the complexity and number of components required for
power-supply monitoring and battery-control functions
in µP systems. They significantly improve system relia-
bility and accuracy compared to separate ICs or
discrete components.
These devices are designed for use in systems powered
by 3.0V or 3.3V supplies. See the selector guide in the
back of this data sheet for similar devices designed for
5V systems. The suffixes denote different reset threshold
voltages: 3.075V (T), 2.925V (S), and 2.625V (R) (see
Reset Threshold
section in the
Detailed Description).
All
these parts are available in 8-pin DIP and SO packages.
Functions offered in this series are as follows:
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____________________________Features
o
o
o
o
o
o
o
o
o
o
o
–——
——–
RESET and RESET Outputs
Manual Reset Input
Precision Supply-Voltage Monitor
200ms Reset Time Delay
Watchdog Timer (1.6sec timeout)
Battery-Backup Power Switching—
Battery Can Exceed V
CC
in Normal Operation
40µA V
CC
Supply Current
1µA Battery Supply Current
Voltage Monitor for Power-Fail or
Low-Battery Warning
–——
——–
Guaranteed RESET Assertion to V
CC
= 1V
8-Pin DIP and SO Packages
MAX690T/S/R, 704T/S/R, 802T/S/R, 804–806T/S/R
______________Ordering Information
PART**
MAX690_CPA
MAX690_CSA
MAX690_C/D
MAX690_EPA
MAX690_ESA
MAX690_MJA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
PIN-PACKAGE
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 CERDIP
Part
MAX690
MAX704
MAX802
MAX804
MAX805
MAX806
________________________Applications
Battery-Powered Computers and Controllers
Embedded Controllers
Intelligent Instruments
Automotive Systems
Critical µP Power Monitoring
Portable Equipment
__________________Pin Configuration
TOP VIEW
V
OUT
V
CC
GND
PFI
( ) ARE FOR MAX804T/S/R, MAX805T/S/R
< >
ARE FOR MAX704T/S/R, MAX806T/S/R
Call toll free 1-800-998-8800 for free samples or literature.
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Re
nu
gI
np
±4%
±4%
±2%
±2%
±4%
±2%
±75mV
±75mV
±2%
±2%
±75mV
±2%
Ordering Information continued on last page.
* Contact factory for dice specifications.
** These parts offer a choice of reset threshold voltage. Select
the letter corresponding to the desired nominal reset threshold
voltage (T = 3.075V, S = 2.925V, R = 2.625V) and insert it into
the blank to complete the part number.
_________Typical Operating Circuits
REGULATED +3.3V OR +3.0V
UNREGULATED
DC
0.1µF
R1
V
CC
V
CC
RESET
(RESET)
PFO
3.6V
LITHIUM
BATTERY
PFI
MAX690T/S/R
WDI
MAX802T/S/R
MAX804T/S/R
MAX805T/S/R
VBATT
GND
0.1µF
V
OUT
0.1µF
V
CC
CMOS RAM
GND
µP
RESET
NMI
I/O LINE GND
BUS
1
2
3
4
MAX690T/S/R
MAX704T/S/R
MAX802T/S/R
MAX804T/S/R
MAX805T/S/R
MAX806T/S/R
DIP/SO
8
7
6
5
VBATT
RESET (RESET)
WDI
<
MR
>
PFO
R2
( ) ARE FOR MAX804T/S/R, MAX805T/S/R
See last page for MAX704T/S/R, MAX806T/S/R.
________________________________________________________________
Maxim Integrated Products
1
3.0V/3.3V Microprocessor Supervisory Circuits
MAX690T/S/R, 704T/S/R, 802T/S/R, 804–806T/S/R
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect to GND)
V
CC
.........................................................................-0.3V to 6.0V
VBATT ....................................................................-0.3V to 6.0V
All Other Inputs ...................-0.3V to the higher of V
CC
or VBATT
Continuous Input Current
V
CC
..................................................................................100mA
VBATT ...............................................................................18mA
GND ..................................................................................18mA
Output Current
– — — – —–
——– —
R E S E T , P F O ....................................................................18mA
V
OUT
................................................................................100mA
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) ..............727mW
SO (derate 5.88mW/°C above +70°C) ...........................471mW
CERDIP (derate 8.00mW/°C above +70°C) ...................640mW
Operating Temperature Ranges
MAX690_C_ _/MAX704_C_ _/MAX80_ _C_ _ ........0°C to +70°C
MAX690_E_ _/MAX704_E_ _/MAX80_ _E_ _. .....-40°C to +85°C
MAX690_M_ _/MAX704_M_ _/MAX80_ _M_ _...-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+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
= 3.17V to 5.5V for the MAX690T/MAX704T/MAX80_T, V
CC
= 3.02V to 5.5V for the MAX690S/MAX704S/MAX80_S, V
CC
= 2.72V to
5.5V for the MAX690R/MAX704R/MAX80_R; VBATT = 3.6V; T
A
= T
MIN
to T
MAX
; unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Operating Voltage Range,
V
CC
, VBATT (Note 1)
SYMBOL
CONDITIONS
MAX690_C, MAX704_C, MAX80_ _C
MAX690_E/M, MAX704_E/M, MAX80_ _E/M
MAX690_C/E, MAX704_C/E,
MAX80_ _C/E, V
CC
< 3.6V
V
CC
Supply Current
(excluding I
OUT
)
–—
–
M R = V
CC
(MAX704_/
MAX806_)
MAX690_C/E, MAX704_C/E,
MAX80_ _C/E, V
CC
< 5.5V
MAX690_M, MAX704_M,
MAX80_ _M, V
CC
< 3.6V
MAX690_M, MAX704_M,
MAX80_ _M, V
CC
< 5.5V
V
CC
Supply Current in Battery-
Backup Mode (excluding I
OUT
)
VBATT Supply Current, Any Mode
(excluding I
OUT
) (Note 2)
Battery Leakage Current
(Note 3)
–—
–
M R = V
CC
(MAX704_/
MAX806_)
V
CC
= 2.0V, VBATT = 2.3V
MIN
1.0
1.1
40
50
40
50
TYP
MAX
5.5
5.5
50
65
µA
55
70
UNITS
V
I
SUPPLY
25
0.4
0.4
0.01
0.01
V
CC
-
0.03
V
CC
-
0.3
V
CC
-
0.035
V
CC
-
0.35
V
CC
-
0.0015
V
CC
-
0.015
V
CC
-
0.15
V
CC
-
0.015
V
CC
-
0.15
V
CC
-
0.0006
50
1
10
0.5
5
µA
MAX690_C/E, MAX704_C/E, MAX80_ _C/E
MAX690_M, MAX704_M, MAX80_ _M
MAX690_C/E, MAX704_C/E, MAX80_ _C/E
MAX690_M, MAX704_M, MAX80_ _M
MAX690_C/E, MAX704_C/E, MAX80_ _C/E,
I
OUT
= 5mA (Note 4)
MAX690_C/E, MAX704_C/E, MAX80_ _C/E
I
OUT
= 50mA
µA
µA
V
OUT
Output Voltage
MAX690_M, MAX704_M, MAX80_ _M
I
OUT
= 5mA (Note 4)
MAX690_M, MAX704_M, MAX80_ _M
I
OUT
= 50mA
I
OUT
= 250µA, V
CC
> 2.5V (Note 4)
V
2
_______________________________________________________________________________________
3.0V/3.3V Microprocessor Supervisory Circuits
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.17V to 5.5V for the MAX690T/MAX704T/MAX80_T, V
CC
= 3.02V to 5.5V for the MAX690S/MAX704S/MAX80_S, V
CC
= 2.72V to
5.5V for the MAX690R/MAX704R/MAX80_R; VBATT = 3.6V; T
A
= T
MIN
to T
MAX
; unless otherwise noted. Typical values are at T
A
= +25˚C.)
PARAMETER
SYMBOL
CONDITIONS
I
OUT
= 250µA, VBATT = 2.3V
V
OUT
in Battery-Backup Mode
I
OUT
= 1mA, VBATT = 2.3V
Battery Switch Threshold,
V
CC
Falling
Battery Switch Threshold,
V
CC
Rising (Note 7)
VBATT - V
CC
, V
SW
> V
CC
> 1.75V (Note 5)
V
SW
VBATT > V
CC
(Note 6)
This value is identical to the reset threshold,
V
CC
rising
MAX690T/704T/805T
MAX802T/804T/806T
MAX690S/704S/805S
Reset Threshold (Note 8)
V
RST
MAX802S/804S/806S
MAX690R/704R/805R
MAX802R/804R/806S
Reset Timeout Period
– —– – — —
—
— —–
P F O , R E S E T Output Voltage
– —– – — —
—
— —–
P F O , R E S E T Output Short to
GND Current (Note 4)
– —– – — —
—
— —–
P F O , R E S E T , RESET
Output Voltage
t
WP
V
OH
I
OS
V
CC
< 3.6V
I
SOURCE
= 50µA
V
CC
= 3.3V, V
OH
= 0V
I
SINK
= 1.2mA;
MAX690_/704_/802_/806_, V
CC
= V
RST
min;
MAX804_/805_, V
CC
= V
RST
max
VBATT = 0V, V
CC
= 1.0V, I
SINK
= 40µA,
MAX690_C, MAX704_C, MAX80_ _C
V
OL
VBATT = 0V, V
CC
= 1.2V, I
SINK
= 200µA,
MAX690_E/M, MAX704_E/M, MAX80_ _E/M
VBATT = 0V,
V
CC
= V
RST
min;
V
RESET
= 0V, V
CC
MAX804_C,
MAX805_C
MAX804_E/M,
MAX805_E/M
-1
-10
V
CC
falling
V
CC
rising
V
CC
falling
V
CC
rising
V
CC
falling
V
CC
rising
V
CC
falling
V
CC
rising
V
CC
falling
V
CC
rising
V
CC
falling
V
CC
rising
3.00
3.00
3.00
3.00
2.85
2.85
2.88
2.88
2.55
2.55
2.59
2.59
140
V
CC
- 0.3
3.075
3.085
3.075
3.085
2.925
2.935
2.925
2.935
2.625
2.635
2.625
2.635
200
V
CC
- 0.05
180
500
3.15
3.17
3.12
3.14
3.00
3.02
3.00
3.02
2.70
2.72
2.70
2.72
280
ms
V
µV
V
65
2.30
MIN
VBATT
- 0.1
TYP
VBATT
- 0.034
VBATT
- 0.14
25
2.40
2.50
MAX
UNITS
MAX690T/S/R, 704T/S/R, 802T/S/R, 804–806T/S/R
V
mV
V
V
V
OL
0.06
0.3
V
– —– – — —
—
— —–
P F O , R E S E T Output Voltage
0.13
0.17
0.3
0.3
1
V
RESET Output Leakage Current
(Note 9)
µA
10
_______________________________________________________________________________________
3
3.0V/3.3V Microprocessor Supervisory Circuits
MAX690T/S/R, 704T/S/R, 802T/S/R, 804–806T/S/R
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.17V to 5.5V for the MAX690T/MAX704T/MAX80_T, V
CC
= 3.02V to 5.5V for the MAX690S/MAX704S/MAX80_S, V
CC
= 2.72V to
5.5V for the MAX690R/MAX704R/MAX80_R; VBATT = 3.6V; T
A
= T
MIN
to T
MAX
; unless otherwise noted. Typical values are at T
A
= +25˚C.)
PARAMETER
PFI Input Threshold
SYMBOL
V
PFT
V
CC
< 3.6V
V
PFI
falling
CONDITIONS
MAX802_C/E, MAX804_C/E,
MAX806_C/E
MAX690_/MAX704_/MAX805_
MIN
1.212
1.187
-25
-500
TYP
1.237
1.237
2
2
10
10
-25
-500
0.3 x V
CC
100
20
0.3 x V
CC
-1
-10
1.12
100
0.01
0.01
1.60
20
1
µA
MAX690_M, MAX802_M,
MAX804_M, MAX805_M
MAX690/MAX802/MAX804/
MAX805 only
10
2.24
sec
ns
20
60
60
500
350
0.7 x V
CC
2
2
MAX
1.262
1.287
25
500
20
25
25
500
0.7 x V
CC
nA
V
ns
ns
µA
V
nA
UNITS
V
PFI Input Current
MAX690_C/E, MAX704_C/E, MAX80_ _C/E
MAX690_M, MAX704_M, MAX80_ _M
V
PFH
V
CC
< 3.6V
MAX690_C/E, MAX704_C/E,
MAX80_ _C/E
MAX690_M, MAX704_M, MAX80_ _M
PFI Hysteresis, PFI Rising
mV
PFI Input Current
–—
–
M R Input Threshold
–—
–
M R Pulse Width
–—
–
M R to Reset Delay
–—
–
M R Pull-Up Current
WDI Input Threshold
V
IH
V
IL
t
MR
t
MD
V
IH
V
IL
MAX690_C/E, MAX704_C/E, MAX80_ _C/E
MAX690_M, MAX704_M, MAX80_ _M
MAX704_/MAX806_ only
MAX704_/MAX806_ only
MAX704_/MAX806_ only
–—
–
MAX704_/MAX806_ only, M R = 0V, V
CC
= 3V
MAX690_/MAX802_/MAX804_/MAX805_ only
MAX690_C/E, MAX802_C/E,
MAX804_C/E, MAX805_C/E
WDI Input Current
0V< V
CC
< 5.5V
Watchdog Timeout Period
WDI Pulse Width
t
WD
V
CC
< 3.6V
MAX690_/MAX802_/MAX804_/MAX805_ only
–—
–
Note 1:
V
CC
supply current, logic input leakage, watchdog functionality (MAX690_/802_/805_/804_), M R functionality
– — —
— —–
(MAX704_/806_), PFI functionality, state of R E S E T (MAX690_/704_/802_/806_), and RESET (MAX804_/805_) tested at
– — —
— —–
– —–
—
VBATT = 3.6V, and V
CC
= 5.5V. The state of R E S E T or RESET and P F O is tested at V
CC
= V
CC
min.
Note 2:
Tested at VBATT = 3.6V, V
CC
= 3.5V and 0V. The battery current will rise to 10µA over a narrow transition window around
V
CC
= 1.9V.
Note 3:
Leakage current into the battery is tested under the worst-case conditions at V
CC
= 5.5V, VBATT = 1.8V and at V
CC
= 1.5V,
VBATT= 1.0V.
Note 4:
Guaranteed by design.
Note 5:
When V
SW
> V
CC
> VBATT, V
OUT
remains connected to V
CC
until V
CC
drops below VBATT. The V
CC
-to-VBATT comparator
has a small 25mV typical hysteresis to prevent oscillation. For V
CC
< 1.75V (typ), V
OUT
switches to VBATT regardless of the
voltage on VBATT.
Note 6:
When VBATT > V
CC
> V
SW
, V
OUT
remains connected to V
CC
until V
CC
drops below the battery switch threshold (V
SW
).
Note 7:
V
OUT
switches from VBATT to V
CC
when V
CC
rises above the reset threshold, independent of VBATT. Switchover back to
– — —
— —–
V
CC
occurs at the exact voltage that causes R E S E T to go high (on the MAX804_/805_, RESET goes low); however
switchover occurs 200ms prior to reset.
Note 8:
The reset threshold tolerance is wider for V
CC
rising than for V
CC
falling to accommodate the 10mV typical hysteresis, which
prevents internal oscillation.
Note 9:
The leakage current into or out of the RESET pin is tested with RESET asserted (RESET output high impedance).
4
_______________________________________________________________________________________
3.0V/3.3V Microprocessor Supervisory Circuits
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
V
CC
-to-V
OUT
ON-RESISTANCE
vs. TEMPERATURE
MAX690-806 TOC01
MAX690T/S/R, 704T/S/R, 802T/S/R, 804–806T/S/R
VBATT-to-V
OUT
ON-RESISTANCE
vs. TEMPERATURE
MAX690-806 TOC02
SUPPLY CURRENT
vs. TEMPERATURE
V
CC
= 5V
SUPPLY CURRENT (µA)
45
MAX690-806 TOC03
5
VBATT = 3.0V
V
CC
-to-V
OUT
ON-RESISTANCE (Ω)
4
V
CC
= 2.5V
3
V
CC
= 3.3V
180
VBATT-to-V
OUT
ON-RESISTANCE (Ω)
V
CC
= 0V
140
VBATT = 3V
100
VBATT = 3.3V
60
VBATT = 5V
20
VBATT = 2V
50
40
VBATT = 3V
PFI = GND
MR/WDI FLOATING
V
CC
= 3.3V
2
V
CC
= 5V
35
1
30
V
CC
= 2.5V
25
–60 –40 –20 0
20 40 60 80 100 120 140
0
–60 –40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
–60 –40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
TEMPERATURE (°C)
BATTERY SUPPLY CURRENT
vs. TEMPERATURE
MAX690-806 TOC04
RESET TIMEOUT PERIOD
vs. TEMPERATURE
MAX690-806 TOC05
RESET-COMPARATOR PROPAGATION
DELAY vs. TEMPERATURE
VBATT = 3.0V
100mV OVERDRIVE
PROPAGATION DELAY (µs)
26
MAX690-806 TOC06
10,000
BATTERY SUPPLY CURRENT (nA)
V
CC
= 0V
PFI = GND
1000
VBATT = 5V
216
RESET TIMEOUT PERIOD (ms)
30
212
V
CC
= 5V
100
VBATT = 3V
208
VBATT = 3.0V
22
10
204
18
1
VBATT = 2V
0.1
–60 –40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
200
V
CC
= 3.3V
196
–60 –40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
14
10
–60 –40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
PFI THRESHOLD
vs. TEMPERATURE
MAX690-806 TOC07
NORMALIZED RESET THRESHOLD
vs. TEMPERATURE
NORMALIZED RESET THRESHOLD (V)
MAX690-806 TOC08
1.240
V
CC
= 3.3V
1.238
PFI THRESHOLD (V)
V
CC
= 5V
1.004
1.002
1.236
V
CC
= 2.5V
1.234
1.000
0.998
1.232
VBATT = 3.0V
1.230
–60 –40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
0.996
VBATT = 3.0V
0.994
–60 –40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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