MAX6800UR44D3-T [MAXIM]
Analog IC ; 模拟IC\n型号: | MAX6800UR44D3-T |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | Analog IC
|
文件: | 总7页 (文件大小:148K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
19-1933 Rev 1; 2/01
3-Pin, Low-Power
µP Reset Circuits
General Description
Features
ꢀ Ultra-Low 0.7V Operating Supply Voltage
ꢀ Low 4.0µA Supply Current
The MAX6800/MAX6801/MAX6802 microprocessor (µP)
supervisory circuits monitor the power supplies in 2.85V
to 5.0V µP and digital systems. They increase circuit
reliability and reduce cost by eliminating external com-
ponents and adjustments.
ꢀ Precision Monitoring of 2.85V to 5.0V Power-
Supply Voltages
These devices perform a single function—they assert a
ꢀ Reset Thresholds Available from 2.63V to 4.80V,
reset signal whenever the V
supply voltage declines
CC
in Approximately 100mV Increments
below a preset threshold, keeping it asserted for a preset
timeout period after V has risen above the reset
ꢀ Fully Specified over Temperature
CC
threshold. The only difference among the three devices
is their output. The MAX6801 (push/pull) and MAX6802
(open-drain) have an active-low RESET output, while the
MAX6800 (push/pull) has an active-high RESET output.
The MAX6800/MAX6801 are guaranteed to be in the cor-
ꢀ Three Power-On Reset Timeout Periods Available
(1ms min, 20ms min, 100ms min)
ꢀ Low Cost
ꢀ Three Available Output Structures: Push/Pull
RESET, Push/Pull RESET, Open-Drain RESET
rect state for V
down to 0.7V. The MAX6802 is guaran-
CC
teed to be in the correct state for V
down to 1.0V.
CC
The reset comparator in these ICs is designed to ignore
fast transients on V . Reset thresholds are factory-
CC
ꢀ Guaranteed RESET/RESET Valid to V
= 0.7V
CC
(MAX6800/MAX6801)
trimmable between 2.63V and 4.80V, in approximately
100mV increments. These devices are available with a
1ms (min), 20ms (min), or 100ms (min) reset pulse
width. Ideal for space-critical applications, the
MAX6800/MAX6801/MAX6802 come packaged in a 3-
pin SOT23. For a lower threshold voltage version, see
the MAX6332/MAX6333/MAX6334.
ꢀ Power-Supply Transient Immunity
ꢀ No External Components Required
ꢀ 3-Pin SOT23 Package
ꢀ Pin Compatible with MAX809/MAX810,
MAX6326/MAX6327/MAX6328, and
MAX6346/MAX6347/MAX6348
Applications
Computers
Controllers
Ordering Information
Intelligent Instruments
Critical µP/µC Power Monitoring
Portable/Battery-Powered Equipment
Automotive
PART*
TEMP. RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
3 SOT23-3
MAX6800UR_ _D_-T
MAX6801UR_ _D_-T
MAX6802UR_ _D_-T
3 SOT23-3
3 SOT23-3
*These devices are available in factory-set V
reset thresh-
CC
olds from 2.63V to 4.80V, in approximately 0.1V increments.
Choose the desired reset threshold suffix from Table 1 and
insert it in the blanks following “UR” in the part number.
Factory-programmed reset timeout periods are also available.
Insert the number corresponding to the desired nominal reset
timeout period (1 = 1ms min, 2 = 20ms min, 3 = 100ms min) in
the blank following “D” in the part number. There are 15 stan-
dard versions with a required order increment of 2500 pieces.
Sample stock is generally held on the standard versions only
(see Selector Guide). Contact the factory for availability of non-
standard versions (required order increment is 10,000 pieces).
All devices available in tape-and-reel only.
Typical Operating Circuit and Pin Configuration appear
at end of data sheet.
Selector Guide appears at end of data sheet.
________________________________________________________________ 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.
3-Pin, Low-Power
µP Reset Circuits
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect to GND)
Continuous Power Dissipation (T = +70°C)
A
V
......................................................................-0.3V to +6V
3-Pin SOT23 (derate 4mW/°C above +70°C)..............320mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
CC
Push/Pull RESET, RESET .......................-0.3V to (V
Open-Drain RESET ..............................................-0.3V to +6V
+ 0.3V)
CC
Input Current (V ).............................................................20mA
Output Current (RESET, RESET).........................................20mA
CC
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, T = -40°C to +125°C, unless otherwise noted. Typical values are at V
A
= +5.0V and T = +25°C, reset not
A
CC
asserted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
0.7
TYP
MAX
5.5
5.5
5.5
5.5
10
UNITS
MAX6800/MAX6801
MAX6802
T
T
= 0°C to +125°C
A
A
1.0
Supply Voltage Range
(Note 2)
V
V
CC
MAX6800/MAX6801
MAX6802
0.78
1.2
= -40°C to +125°C
V
V
= +3.0V
= +5.0V
4
5
CC
CC
Supply Current
Reset Threshold
I
No load
µA
V
CC
12
V
V
TH
+ 1.8%
TH
T
= +25°C
V
V
A
TH
TH
- 1.8%
MAX680_UR_ _D_-T,
Table 1
V
TH
V
V
TH
+ 3%
TH
T = -40°C to +125°C
A
- 3%
V
Falling Reset Delay
V
falling at 10V/ms
CC
30
µs
CC
MAX680_UR_ _D1-T
MAX680_UR_ _D2-T
MAX680_UR_ _D3-T
1
1.5
30
2
Reset Active Timeout Period
t
20
40
ms
RP
100
150
200
0.4
0.3
0.4
I
I
I
= 50µA, V
≥ 1.0V
≥ 2.5V
SINK
SINK
SINK
CC
RESET Output Low Voltage
(MAX6801/MAX6802)
Reset
asserted
V
V
V
= 1.2mA, V
= 1.2mA, V
OL
OH
OH
CC
≥ 4.25V
CC
I
= 500µA, V
= 800µA, V
≥ 3.0V 0.8 x V
≥ 5.0V 0.8 x V
SOURCE
CC
CC
RESET Output High Voltage
(MAX6801)
Reset not
asserted
V
V
I
SOURCE
CC
CC
I
= 1µA, V
≥1.0V
0.8 x V
0.8 x V
SOURCE
CC
CC
CC
CC
Reset
asserted
I
= 200µA, V
≥1.8V
SOURCE
CC
RESET Output Voltage
(MAX6800)
I
= 800µA, V ≥ 4.25V 0.8 x V
V
SOURCE
CC
I
= 1.2mA, V
≥3.0V
≥5.0V
0.3
0.4
Reset not
asserted
SINK
CC
V
OL
I
= 3.2mA, V
SINK
CC
RESET Output Leakage Current
(MAX6802)
V
> V , RESET not asserted
0.5
µA
CC
TH
Note 1: All parts are production tested at T = +25°C. Overtemperature limits are guaranteed by design and not production tested.
A
Note 2: I
for the MAX6800 is I00nA. I
for the MAX6801 is 100nA. I
for the MAX6802 is 50µA.
SOURCE
SINK
SINK
2
_______________________________________________________________________________________
3-Pin, Low-Power
µP Reset Circuits
Typical Operating Characteristics
(Reset not asserted, T = +25°C, unless otherwise noted.)
A
NORMALIZED RESET TIMEOUT PERIOD
vs. TEMPERATURE
RESET (V )
OL
vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
1.050
1.040
1.030
1.020
1.010
1.000
0.990
0.980
0.970
0.960
0.950
80
60
40
20
0
V
SINK
= 2.93V
= 500µA
TH
+125°C
I
RESET ASSERTED
MAX6801/MAX6802
V
= +5.0V
+85°C
CC
+25°C
-40°C
V
= +3.3V
CC
-50 -25
0
25
50
75 100 125
-50 -25
0
25
50
75 100 125
1.0
1.5
2.0
2.5
3.0
TEMPERATURE (°C)
TEMPERATURE (°C)
V
(V)
CC
MAXIMUM TRANSIENT DURATION
vs. RESET COMPARATOR OVERDRIVE
RESET (V
vs. SUPPLY VOLTAGE
)
V
FALLING PROPAGATION DELAY
vs. TEMPERATURE
OH
CC
600
500
400
300
200
100
0
100
75
50
25
0
100
V
= 2.93V
TH
90
80
70
60
50
40
30
20
10
0
I
= 100µA
SOURCE
RESET ASSERTED
(MAX6800)
V
= FALLING AT 1V/ms
CC
+125°C
RESET OCCURS
+85°C
+25°C
RESET DOES
NOT OCCUR
V
CC
= FALLING AT 10V/ms
-40°C
0.1
1
10
100
1000
1.0
1.5
2.0
2.5
3.0
-50 -25
0
25
50
75 100 125
RESET COMPARATOR OVERDRIVE (mV)
V
(V)
TEMPERATURE (°C)
CC
Pin Description
PIN
NAME
FUNCTION
MAX6801/
MAX6802
1
MAX6800
1
GND
Ground
Active-Low Reset Output. RESET is asserted while V
is below the reset
CC
threshold and remains asserted for a reset timeout period (t ) after V
rises above the reset threshold. RESET on the MAX6801 is push/pull.
RESET on the MAX6802 is open-drain.
RP
CC
—
2
RESET
Active-High Reset Output. RESET is asserted while V
is below the reset
CC
2
3
—
RESET
threshold and remains asserted for a reset timeout period (t ) after V
rises above the reset threshold. RESET on the MAX6800 is push/pull.
Supply Voltage Input
RP
CC
3
V
CC
_______________________________________________________________________________________
3
3-Pin, Low-Power
µP Reset Circuits
Negative-Going V
CC
Transients
Applications Information
Interfacing to µPs with Bidirectional
Reset Pins
In addition to issuing a reset to the µP during power-up,
power-down, and brownout conditions, these devices are
relatively immune to short-duration, negative-going V
CC
Since the RESET output on the MAX6802 is open-drain,
this device interfaces easily with µPs that have bidirec-
tional reset pins, such as the Motorola 68HC11.
Connecting the µP supervisor’s RESET output directly
to the microcontroller’s (µC’s) RESET pin with a single
pullup resistor allows either device to assert reset
(Figure 1).
transients (glitches). The Typical Operating Characteristics
show the Maximum Transient Duration vs. Reset
Comparator Overdrive graph. The graph shows the maxi-
mum pulse width that a negative-going V transient may
CC
typically have without issuing a reset signal. As the ampli-
tude of the transient increases, the maximum allowable
pulse width decreases.
V
CC
V
CC
V
CC
V
V
CC
CC
100kΩ*
µP
MOTOROLA
68HCXX
100kΩ
MAX6801
MAX6800
MAX6802
RESET
RESET
RESET
RESET
100kΩ
GND
GND
GND
GND
(a)
(b)
*ASSUMES HIGH-Z RESET INPUT TO THE µP
Figure 1. Interfacing to µPs with Bidirectional Reset Pins
Figure 2. Ensuring Reset Valid Down to V
= 0
CC
Pin Configuration
Typical Operating Circuit
TOP VIEW
V
CC
1
GND
V
V
CC
CC
MAX6800
MAX6801
MAX6802
3
V
CC
µP
MAX6801
RESET
RESET
GND
GND
2
RESET (RESET)
SOT23-3
(
) ARE FOR MAX6800
4
_______________________________________________________________________________________
3-Pin, Low-Power
µP Reset Circuits
Ensuring a Valid Reset Output
Down to VCC = 0
to load RESET and small enough to pull it low. For the
MAX6800 application, where RESET must be valid to
V
V
= 0, a 100kΩ pullup resistor between RESET and
When V
falls below 1V and approaches the minimum
CC
CC
CC
will hold RESET high when V
falls below 0.7V
operating voltage of 0.7V, push/pull-structured reset
sinking (or sourcing) capabilities decrease drastically.
High-impedance CMOS-logic inputs connected to the
RESET pin can drift to indeterminate voltages. This
does not present a problem in most cases, since most
CC
(Figure 2b).
Since the MAX6802 has an open-drain, active-low out-
put, it typically uses a pullup resistor. With this device,
RESET will most likely not maintain an active condition,
but will drift to a non-active level due to the pullup
resistor and the reduced sinking capability of the open-
drain device. Therefore, this device is not recommend-
ed for applications where the RESET pin is required to
µPs and circuitry do not operate when V
drops
CC
below 1V. For the MAX6801 application, where RESET
must be valid down to 0, adding a pulldown resistor
between RESET and GND removes stray leakage cur-
rents, holding RESET low (Figure 2a). The pulldown
resistor value is not critical; 100kΩ is large enough not
be valid down to V
= 0.
CC
Table 1. Factory-Trimmed Reset Thresholds
RESET
THRESHOLD
SUFFIX
T
= +25°C
T = -40°C to +125°C
A
A
MIN
TYP (V
)
TH
MAX
4.886
4.785
4.713
4.581
4.459
4.377
4.276
4.174
4.072
3.970
3.868
3.767
3.665
3.563
3.461
3.359
3.258
3.135
3.054
2.983
2.850
2.749
2.677
MIN
MAX
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
4.714
4.615
4.547
4.419
4.301
4.223
4.124
4.026
3.928
4.830
3.732
3.633
3.535
3.437
3.339
3.241
3.142
3.025
2.946
2.877
2.750
2.651
2.583
4.80
4.70
4.63
4.50
4.38
4.30
4.20
4.10
4.00
3.90
3.80
3.70
3.60
3.50
3.40
3.30
3.20
3.08
3.00
2.93
2.80
2.70
2.63
4.656
4.559
4.491
4.365
4.249
4.171
4.074
3.977
3.880
3.783
3.686
3.589
3.492
3.395
3.298
3.201
3.104
2.988
2.910
2.842
2.716
2.619
2.551
4.944
4.841
4.769
4.635
4.511
4.429
4.326
4.223
4.120
4.017
3.914
3.811
3.708
3.605
3.502
3.399
3.296
3.172
3.090
3.018
2.884
2.781
2.709
_______________________________________________________________________________________
5
3-Pin, Low-Power
µP Reset Circuits
Selector Guide (Standard Versions*)
MIN RESET
TIMEOUT (ms)
SOT
TOP MARK
PART
OUTPUT STAGE
NOMINAL V (V)
TH
MAX6800UR26D3-T
MAX6800UR29D3-T
MAX6800UR31D3-T
MAX6800UR44D3-T
MAX6800UR46D3-T
MAX6801UR26D3-T
MAX6801UR29D3-T
MAX6801UR31D3-T
MAX6801UR44D3-T
MAX6801UR46D3-T
MAX6802UR26D3-T
MAX6802UR29D3-T
MAX6802UR31D3-T
MAX6802UR44D3-T
MAX6802UR46D3-T
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Push/Pull RESET
Open-Drain RESET
Open-Drain RESET
Open-Drain RESET
Open-Drain RESET
Open-Drain RESET
2.63
2.93
3.08
4.38
4.63
2.63
2.93
3.08
4.38
4.63
2.63
2.93
3.08
4.38
4.63
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
FZIE
FZIF
FZIG
FZIH
FZII
FZIK
FZIM
FZIN
FZIO
FZIP
FZIQ
FZIR
FZIS
FZIT
FZIU
*Sample stock is generally held on all standard versions.
Chip Information
TRANSISTOR COUNT: 505
PROCESS: BiCMOS
6
_______________________________________________________________________________________
3-Pin, Low-Power
µP Reset Circuits
Package Information
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.
7 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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