MAX971CSA [MAXIM]
Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators; 超低功耗，漏极开路输出，单/双电源比较器
| 型号： | MAX971CSA |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators |
| 文件： | 总16页 (文件大小：111K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-0450; Rev 0; 11/95
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
_______________Ge n e ra l De s c rip t io n
____________________________Fe a t u re s
The MAX971–MAX974 and MAX981–MAX984 single/
dual/quad low-voltage comparators feature the lowest
p owe r c ons ump tion a va ila b le . The s e mic rop owe r
d e vic e s d ra w le s s tha n 4µA s up p ly c urre nt ove r
temperature (MAX971/MAX972, MAX981/MAX982), and
inc lud e a n inte rna l 1.182V ± 1% (MAX971/MAX973/
MAX974) or ±2% (MAX981–MAX984) voltage reference
and programmable hysteresis.
♦ µMAX Package—Smallest 8-Pin SO
(MAX9_1/MAX9_2/MAX9_3)
♦ Ultra-Low 4µA Max Quiescent Current
Over Extended Temp. Range (MAX971/MAX981)
♦ Power Supplies: Single +2.5V to +11V
Dual ±1.25V to ±5.5V
♦ Input Voltage Range Includes Negative Supply
♦ Internal 1.182V ±1% Bandgap Reference
Ideal for 3V or 5V single-supply applications, these
devices operate from a single +2.5V to +11V supply (or
±1.25V to ±5.5V dual supplies), and each comparator’s
input voltage ranges from the negative supply rail to within
1.3V of the positive supply.
♦ 12µs Propagation Delay (10mV Overdrive)
♦ Output Has Separate GND Pin (MAX9_1/MAX9_4)
The single MAX971 and MAX981 and the dual MAX973
and MAX982/MAX983 provide a unique, simple method
for adding hysteresis without feedback or complicated
e q ua tions , s imp ly b y us ing the HYST p in p lus two
resistors.
________________________Ap p lic a t io n s
Battery-Powered Systems
Level Translators
Threshold Detectors
Oscillator Circuits
The MAX971–MAX974 and MAX981–MAX984’s open-
drain outputs permit wire-ORed configurations. Thanks to
an 11V output range and separate GND pin for the output
transistor (MAX971/MAX974, MAX981/MAX984), these
devices are ideal for level translators and bipolar to single-
ended converters. For similar devices with complementary
output stages, see the MAX921–MAX924 (1% reference)
and the MAX931–MAX934 (2% reference).
Window Comparators
______________Ord e rin g In fo rm a t io n
PART
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
8 Plastic DIP
8 SO
MAX971CPA
MAX971CSA
MAX971CUA
MAX971C/D
8 µMAX
Dice*
Ordering Information continued at end of data sheet.
* Dice are tested at T = +25°C, DC parameters only.
A
__________Typ ic a l Op e ra t in g Circ u it
8-Pin
DIP/SO/µMAX
MAX971
MAX972
MAX973
MAX974
MAX981
MAX982
MAX983
MAX984
1%
None
1%
1
2
2
4
1
2
2
4
Yes
No
V
IN
8-Pin
DIP/SO/µMAX
7
V+
3
IN+
8-Pin
DIP/SO/µMAX
Yes
No
OUT 8
4 IN-
1%
16-Pin DIP/SO
8-Pin
DIP/SO/µMAX
2%
Yes
Yes
Yes
No
HYST
5
8-Pin
DIP/SO/µMAX
2%
MAX971
MAX981
6 REF
8-Pin
DIP/SO/µMAX
GND
1
V-
2%
2
2%
16-Pin DIP/SO
THRESHOLD DETECTOR
________________________________________________________________ Maxim Integrated Products
1
Ca ll t o ll fre e 1 -8 0 0 -9 9 8 -8 8 0 0 fo r fre e s a m p le s o r lit e ra t u re .
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
ABSOLUTE MAXIMUM RATINGS
V+ to V-, V+ to GND, GND to V-................................-0.3V, +12V
Inputs
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C)........640mW
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)..842mW
16-Pin SO (derate 8.70mW/°C above +70°C) ................696mW
16-Pin CERDIP (derate 10.00mW/°C above +70°C)......800mW
Operating Temperature Ranges
MAX97_C_ _/MAX98_C_ _..................................0°C to +70°C
MAX97_E_ _/MAX98_E_ _ ...............................-40°C to +85°C
MAX97_MJ_/MAX98_MJ_ .............................-55°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Current: IN_+, IN_-, HYST..............................................20mA
Voltage: IN_+, IN_-, HYST ...............(V+ + 0.3V) to (V- - 0.3V)
Outputs
Current: REF...................................................................20mA
OUT_................................................................50mA
Voltage: REF....................................(V+ + 0.3V) to (V- - 0.3V)
OUT_ (MAX9_1/9_4) ...............+12V to (GND - 0.3V)
(MAX9_2/9_3) ....................+12V to (V- - 0.3V)
OUT_ Short-Circuit Duration ..................................Continuous
Continuous Power Dissipation (T = +70°C)
A
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ...727mW
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: 5V OPERATION
(V+ = 5V, V- = GND = 0V, T = T
A
to T
, unless otherwise noted. Typical values are at T = +25°C.)
MIN
MAX
A
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
POWER REQUIREMENTS
Supply Voltage Range
Output Voltage Range
(Note 1)
2.5
0
11
11
3.2
4
V
V
T
= +25°C
2.5
2.5
3.1
5.5
A
MAX9_1,
HYST = REF
C/E temp. ranges
M temp. range
5
T
A
= +25°C
3.2
4
MAX972
C/E temp. ranges
M temp. range
5
Supply Current
IN+ = IN- + 100mV
µA
T
A
= +25°C
4.5
6
MAX982/
MAX9_3,
HYST = REF
C/E temp. ranges
M temp. range
7.5
6.5
8.5
11
7/1–MAX984
T
A
= +25°C
MAX9_4
C/E temp. ranges
M temp. range
COMPARATOR
Input Offset Voltage
V
= 2.5V
±10
±5
mV
nA
CM
C/E temp. ranges
M temp. range
±0.01
±0.02
Input Leakage Current (IN-, IN+)
Input Leakage Current (HYST)
IN+ = IN- = 2.5V
±40
MAX9_1/MAX982/MAX9_3
nA
V
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Voltage Noise
V-
V+ - 1.3
1.0
V- to (V+ - 1.3V)
0.1
0.1
20
mV/V
mV/V
V+ = 2.5V to 11V
1.0
100Hz to 100kHz
µV
RMS
Hysteresis Input Voltage Range
MAX9_1/MAX982/MAX9_3
REF - 0.05
REF
V
Overdrive = 10mV
Overdrive = 100mV
12
4
Response Time
(high-to-low transition)
T = +25°C, 100pF load,
A
1MΩ pull-up to V+
µs
Response Time
(low-to-high transition) (Note 2)
T
A
= +25°C, 100pF load, 1MΩ pull-up to V+
300
µs
2
_______________________________________________________________________________________
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
ELECTRICAL CHARACTERISTICS: 5V OPERATION (continued)
(V+ = 5V, V- = GND = 0V, T = T
A
to T
, unless otherwise noted. Typical values are at T = +25°C.)
MIN
MAX
A
PARAMETER
CONDITIONS
MAX9_2/MAX9_3, I = 1.8mA for C/E temp. ranges,
MIN
TYP
MAX
UNITS
OUT
V- + 0.4
I
= 1.2mA for M temp. range
OUT
Output Low Voltage
V
MAX9_1/MAX9_4, I
= 1.8mA for C/E temp. ranges,
OUT
GND + 0.4
100
I
= 1.2mA for M temp. range
OUT
Output Leakage Current
V
OUT
= 11V
nA
REFERENCE (MAX9_1/MAX982/MAX9_3/MAX9_4 ONLY)
C temp. range
1.170
1.182
25
1.194
1.206
1.217
Reference Voltage
Source Current
E temp. range
M temp. range
1.158
V
1.147
T
A
= +25°C
15
6
C/E temp. ranges
M temp. range
µA
µA
4
T
= +25°C
8
15
A
Sink Current
C/E temp. ranges
M temp. range
4
2
Voltage Noise
100Hz to 100kHz
100
µV
RMS
ELECTRICAL CHARACTERISTICS: 3V OPERATION
(V+ = 5V, V- = GND = 0V, T = T
A
to T
, unless otherwise noted. Typical values are at T = +25°C.)
MIN
MAX
A
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
POWER REQUIREMENTS
T
= +25°C
2.4
3.0
3.8
4.8
3.0
3.8
4.8
4.3
5.8
7.2
6.2
8.0
10.5
A
MAX9_1 C/E temp. ranges
M temp. range
T
A
= +25°C
2.4
3.4
5.2
MAX972 C/E temp. ranges
M temp. range
HYST = REF,
IN+ = (IN- + 100mV)
Supply Current
µA
T
A
= +25°C
MAX982/
MAX9_3
C/E temp. ranges
M temp. range
T
A
= +25°C
MAX9_4 C/E temp. ranges
M temp. range
COMPARATOR
Input Offset Voltage
V
= 1.5V
±10
±5
mV
nA
CM
C/E temp. ranges
M temp. range
±0.01
±0.02
Input Leakage Current (IN-, IN+)
Input Leakage Current (HYST)
IN+ = IN- = 1.5V
±40
MAX9_1/MAX982/MAX9_3
nA
V
Input Common-Mode Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
V-
V+ - 1.3
V- to (V+ - 1.3V)
V+ = 2.5V to 11V
0.2
0.1
1
1
mV/V
mV/V
_______________________________________________________________________________________
3
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
ELECTRICAL CHARACTERISTICS: 3V OPERATION (continued)
(V+ = 5V, V- = GND = 0V, T = T
A
to T
, unless otherwise noted. Typical values are at T = +25°C.)
MIN
MAX
A
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
µV
Voltage Noise
100Hz to 100kHz
MAX9_1/MAX982/MAX9_3
T = +25°C, 100pF load,
A
20
RMS
Hysteresis Input Voltage Range
REF - 0.05
REF
V
Overdrive = 10mV
Overdrive = 100mV
12
4
Response Time
(high-to-low transition)
µs
1MΩ pull-up to V+
Response Time
(low-to-high transition) (Note 2)
T
A
= +25°C, 100pF load, 1MΩ pull-up to V+
300
µs
MAX9_2/MAX9_3, I
= 0.8mA for C/E temp. ranges,
OUT
V- + 0.4
I
= 0.6mA for M temp. range
OUT
Output Low Voltage
V
MAX9_1/MAX9_4, I
= 0.8mA for C/E temp. ranges,
OUT
GND + 0.4
100
I
= 0.6mA for M temp. range
OUT
Output Leakage Current
V
OUT
= 11V
nA
REFERENCE
C temp. range
E temp. range
M temp. range
1.170
1.182
25
1.194
1.206
1.217
Reference Voltage
Source Current
1.158
V
1.147
T
A
= +25°C
15
6
C/E temp. ranges
M temp. range
µA
µA
4
T
A
= +25°C
8
15
Sink Current
C/E temp. ranges
M temp. range
4
2
Voltage Noise
100Hz to 100kHz
100
µV
RMS
Note 1: MAX974/MAX984 comparators work below 2.5V; see Low-Voltage Operation section for more details.
Note 2: Low-to-high response time is the result of the 1MΩ pull-up and the 100pF capacitive load, based on three time constants.
A faster response time is achieved with a smaller RC.
7/1–MAX984
__________________________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s
(V+ = 5V, V- = GND, T = +25°C, unless otherwise noted.)
A
OUTPUT VOLTAGE LOW
vs. LOAD CURRENT
REFERENCE OUTPUT VOLTAGE vs.
MAX971/MAX973/MAX974
REFERENCE VOLTAGE vs. TEMPERATURE
OUTPUT LOAD CURRENT
1.22
1.21
1.20
1.19
1.18
2.5
2.0
1.190
V+ = 5V
SINK
MILITARY TEMP. RANGE
EXTENDED TEMP. RANGE
1.185
1.180
SOURCE
V+ = 3V
COMMERCIAL
TEMP. RANGE
1.5
1.0
1.175
1.170
1.165
1.160
1.155
1.17
1.16
1.15
1.14
V+ = 5V
0.5
0
OR
V+ = 3V
0
4
8
12
16
20
0
5
10
15
20
25
30
-60 -40 -20
0
20 40 60 80 100 120 140
LOAD CURRENT (mA)
OUTPUT LOAD CURRENT (µA)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
____________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s (c o n t in u e d )
(V+ = 5V, V- = GND, T = +25°C, unless otherwise noted.)
A
MAX9_1
SUPPLY CURRENT vs.
MAX972
MAX982/MAX9_3
TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
4.5
4.0
4.5
4.0
5.0
IN+ = IN- + 100mV
IN+ = (IN- + 100mV)
4.5
4.0
3.5
3.0
2.5
2.0
1.5
V+ = 5V, V- = - 5V
3.5
3.0
V+ = 5V, V- = 0V
V+ = 10V, V- = 0V
3.5
3.0
2.5
2.0
V+ = 3V, V- = 0V
V+ = 5V, V- = 0V
V+ = 3V, V- = 0V
2.5
2.0
V+ = 3V, V- = 0V
V+ = 5V, V- = 0V
-60
-20
20
60
100
140
-60
-20
20
60
100
140
-60
-20
20
60
100
140
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX9_4
MAX9_1/MAX982/MAX9_3
HYSTERESIS CONTROL
SUPPLY CURRENT vs.
LOW SUPPLY VOLTAGES
MAX9_4
SUPPLY CURRENT vs. TEMPERATURE
10
10
9
80
IN+ = (IN- + 100mV)
60
40
20
OUTPUT HIGH
8
1
7
V+ = 5V, V- = -5V
0
-20
-40
-60
NO CHANGE
6
0.1
V+ = 5V, V- = 0V
V+ = 3V, V- = 0V
5
OUTPUT LOW
10
4
0.01
3
-80
1.0
1.5
2.0
2.5
-60
-20
20
60
100
140
0
20
-V
30
(mV)
40
50
SINGLE-SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
V
REF HYST
RESPONSE TIME vs.
LOAD CAPACITANCE
RESPONSE TIME FOR VARIOUS
INPUT OVERDRIVES (V
MAX9_1/MAX972/MAX9_4
TRANSFER FUNCTION
)
OHL
18
16
5.0
4.5
+5V
V- = 0V
5
10k
100k
V
0
4
3
2
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
14
12
10mV
20mV
10µF
V
OHL
100mV
10
8
1
0
50mV
100
0
6
4
2
0
20
40
60
80
100
-2
2
6
10
14
18
-0.3
-0.1
0.1
0.2
0.3
-0.2
0
LOAD CAPACITANCE (nF)
RESPONSE TIME (µs)
IN+ INPUT VOLTAGE (mV)
_______________________________________________________________________________________
5
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
____________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s (c o n t in u e d )
(V+ = 5V, V- = GND, T = +25°C, unless otherwise noted.)
A
SHORT-CIRCUIT SINK CURRENT
vs. SUPPLY VOLTAGE
RESPONSE TIME
AT LOW SUPPLY VOLTAGES (V
MAX924 RESPONSE TIME
AT LOW SUPPLY VOLTAGES
)
OHL
25
20
15
1000
100
OUT CONNECTED TO V+
GND CONNECTED TO V-
R
= 10kΩ
PULL-UP
100
10
10
1
10
5
-20mV
-100mV
SINK CURRENT AT V
OUT
= 0.4V
2.0
0
1
0.1
0
5
10
1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4
SINGLE-SUPPLY VOLTAGE (V)
1.0
1.5
2.5
TOTAL SUPPLY VOLTAGE (V)
SINGLE-SUPPLY VOLTAGE (V)
____________________________________________________________P in De s c rip t io n s
PIN
NAME
FUNCTION
MAX971
MAX981
MAX973
MAX983
MAX972 MAX982
Ground. Connect to V- for single-supply operation. Output
transistor pulls to GND.
1
—
2
—
1
—
1
—
1
GND
OUTA
V-
Comparator A Open-Drain Output. Sinks current to V-.
Negative Supply. Connect to ground for single-supply operation
(MAX9_1).
2
2
2
7/1–MAX984
3
—
3
—
3
—
3
IN+
INA+
IN-
Noninverting Comparator Input
—
4
Noninverting Input of Comparator A
Inverting Comparator Input
—
4
—
—
—
4
—
—
4
—
—
—
INA-
INB-
INB+
Inverting Input of Comparator A
5
Inverting Input of Comparator B
6
—
Noninverting Input of Comparator B
Hysteresis Input. Connect to REF if not used. Input voltage range is
5
—
5
5
HYST
from V
to V
- 50mV.
REF
REF
6
7
—
7
6
7
6
7
REF
V+
Reference Output. 1.182V with respect to V-.
Positive Supply
8
—
8
—
8
—
8
OUT
OUTB
Comparator Output. Sinks current to GND.
Comparator B Open-Drain Output. Sinks current to V-.
—
6
_______________________________________________________________________________________
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
_______________________________________________P in De s c rip t io n s (c o n t in u e d )
PIN
NAME
FUNCTION
MAX974
MAX984
1
2
OUTB
OUTA
V+
Comparator B Open-Drain Output. Sinks current to GND.
Comparator A Open-Drain Output. Sinks current to GND.
Positive Supply
3
4
INA-
INA+
INB-
INB+
REF
Inverting Input of Comparator A
5
Noninverting Input of Comparator A
6
Inverting Input of Comparator B
7
Noninverting Input of Comparator B
8
Reference Output. 1.182V with respect to V-.
Negative Supply. Connect to ground for single-supply operation.
Inverting Input of Comparator C
9
V-
10
11
12
13
14
15
16
INC-
INC+
IND-
IND+
GND
OUTD
OUTC
Noninverting Input of Comparator C
Inverting Input of Comparator D
Noninverting Input of Comparator D
Ground. Connect to V- for single-supply operation.
Comparator D Open-Drain Output. Sinks current to GND.
Comparator C Open-Drain Output. Sinks current to GND.
_______________________________________________________________________________________
7
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
P o w e r-S u p p ly a n d In p u t S ig n a l Ra n g e s
_______________De t a ile d De s c rip t io n
This family of devices operates from a single +2.5V to
+11V power supply. The MAX9_1 and MAX9_4 have a
separate ground for the output driver, allowing operation
with d ua l s up p lie s ra ng ing from ± 1.25V to ± 5.5V.
Connect V- to GND when operating the MAX9_1 or
MAX9_4 from a single sup ply. The ma ximum tota l
supply voltage in this case is still 11V.
The MAX971–MAX974 and MAX981–MAX984 comprise
various combinations of a micropower 1.182V reference
and micropower comparators. The Typical Operating
Circuit shows the MAX971/MAX981 configuration, and
Figures 1a–1d show the MAX9_2–MAX9_4 configurations.
Inte rna l hys te re s is in the MAX9_1, MAX982, a nd
MAX9_3 provides the easiest method for implementing
hysteresis. It also produces faster hysteresis action and
consumes much less current than circuits using external
positive feedback.
For proper comparator operation, the input signal can
range from the negative supply (V-) to within one volt of
the p os itive s up p ly (V+ - 1V). The g ua ra nte e d
common-mode input voltage range extends from V- to
(V+ - 1.3V). The inputs can be taken above and below
the supply rails by up to 300mV without damage.
MAX9_3
1
OUTA
OUTB 8
MAX972
1
OUTA
OUTB
8
2
3
4
V-
V+
REF
7
6
5
2
3
4
V-
V+
INB+
INB-
7
6
5
INA+
INB-
INA+
INA-
HYST
V-
Figure 1c. MAX973/MAX983 Functional Diagram (Window
Comparator)
Figure 1a. MAX972 Functional Diagram
7/1–MAX984
MAX9_4
OUTB
OUTA
OUTC 16
OUTD 15
1
2
3 V+
GND 14
IND+ 13
IND- 12
INA-
4
5
MAX982
1
OUTA
OUTB 8
INA+
2
3
4
V-
V+
REF
7
6
5
INA+
INB+
6
7
8
INB-
INB+
REF
INC+ 11
INC- 10
HYST
V-
V-
9
Figure 1d. MAX974/MAX984 Functional Diagram
Figure 1b. MAX982 Functional Diagram
8
_______________________________________________________________________________________
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
The negative supply does not affect the output sink
current. The positive supply provides gate drive for the
output N-channel MOSFET and heavily influences the
outp ut c urre nt c a p a b ility, e s p e c ia lly a t low s up p ly
voltages (see Typical Operating Characteristics section).
THRESHOLDS
IN+
IN-
The MAX9_2 and MAX9_3 have no GND pin, and their
outputs sink current to V-.
HYSTERESIS
BAND
V
- V
REF HYST
V
HB
Vo lt a g e Re fe re n c e
The internal bandgap voltage reference has an output
of 1.182V a b ove V-. Note tha t the REF volta g e is
referenced to V-, not to GND. Its accuracy is ±1%
(MAX971/MAX973/MAX974) or ±2% (MAX981–MAX984)
in the 0°C to +70°C range. The REF output is typically
capable of sourcing 25µA and sinking 15µA. Do not
bypass the REF output.
OUT
No is e Co n s id e ra t io n s
Although the comparators have a very high gain, useful
gain is limited by noise. This is shown in the Transfer
Function graph (see Typical Operating Characteristics).
As the inp ut volta g e a p p roa c he s the c omp a ra tor’s
offset, the output begins to bounce back and forth; this
Figure 2. Threshold Hysteresis Band
Low-Voltage Operation: V+ = 1V (MAX9_4 Only)
The guaranteed minimum operating voltage is 2.5V (or
±1.25V). As the total supply voltage falls below 2.5V,
performance degrades and the supply current falls.
The re fe re nc e will not func tion b e low a b out 2.2V,
although the comparators will continue to operate with a
total supply voltage as low as 1V. While the MAX9_4
has comparators that may be used at supply voltages
below 2V, the MAX9_1/MAX9_2/MAX9_3 may not be
used with supply voltages below 2.5V.
peaks when V = V . (The lowpass filter shown on the
IN
OS
graph averages out the bouncing, making the transfer
func tion e a s y to ob s e rve .) Cons e q ue ntly, the
comparator has an effective wideband peak-to-peak
nois e of a round 300µV. The volta g e re fe re nc e ha s
peak-to-peak noise approaching 1mV. Thus, when a
comparator is used with the reference, the combined
peak-to-peak noise is about 1mV. This, of course, is
muc h hig he r tha n the RMS nois e of the ind ivid ua l
c omp one nts . Ta ke c a re in your la yout to a void
capacitive coupling from any output to the reference
pin. Crosstalk can significantly increase the actual
noise of the reference.
At low supply voltages, the comparators’ output sink
c a p a b ility is re d uc e d a nd the p rop a g a tion d e la y
increases (see Typical Operating Characteristics). The
useful input voltage range extends from the negative
supply to a little under 1V below the positive supply,
which is slightly closer to the positive rail than when the
device operates from higher supply voltages. Test your
prototype over the full temperature and supply-voltage
range if you anticipate operation below 2.5V.
2.5V TO 11V
7
I
REF
6
5
Co m p a ra t o r Ou t p u t
With 100mV of overdrive, propagation delay is typically
3µs. The Typical Operating Characteristics show the
propagation delay for various overdrive levels. The
open-drain outputs are intended for wire-ORed and
le ve l-s hifting a p p lic a tions . The ma ximum outp ut
voltage is 11V above V-, and may be applied even
when no supply voltage is present (V+ = V-).
V+
REF
MAX9_1
MAX982
MAX9_3
R1
R2
HYST
V-
2
The MAX9_1 and MAX9_4 outputs sink current to GND,
making these devices ideal for bipolar to single-ended
conversion and level-shifting applications.
Figure 3. Programming the HYST Pin
_______________________________________________________________________________________
9
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
__________Ap p lic a t io n s In fo rm a t io n
V+
Hys t e re s is
Hysteresis increases the comparators’ noise margin by
increasing the upper threshold and decreasing the
lower threshold (Figure 2).
R
H
R
PULL-UP
V
IN
Hysteresis (MAX9_1/MAX982/MAX9_3)
To add hysteresis to the MAX9_1, MAX982, or MAX9_3,
c onne c t re s is tor R1 b e twe e n REF a nd HYST, a nd
connect resistor R2 between HYST and V- (Figure 3). If
no hysteresis is required, connect HYST to REF. When
hysteresis is added, the upper threshold increases by
the same amount that the lower threshold decreases.
The hysteresis band (the difference between the upper
V+ OUT
V-
MAX9_4
GND
V
REF
and lower thresholds, V ) is approximately equal to
HB
twice the voltage between REF and HYST. The HYST
input can be adjusted to a maximum voltage of REF
a nd to a minimum volta g e of (REF - 50mV). The
maximum difference between REF and HYST (50mV)
will therefore produce a 100mV max hysteresis band.
Use the following equations to determine R1 and R2:
Figure 4. External Hysteresis
Bo a rd La yo u t a n d Byp a s s in g
Power-supply bypass capacitors are not needed if the
supply impedance is low, but 100nF bypass capacitors
should be used when the supply impedance is high or
when the supply leads are long. Minimize signal lead
lengths to reduce stray capacitance between the input
and output that might cause instability. Do not bypass
the reference output.
V
HB
R1 =
2 × I
(
)
REF
V
HB
1.182 –
2
R2 =
I
REF
Win d o w De t e c t o r
The MAX9_3 is id e a l for ma king wind ow d e te c tors
(undervoltage/overvoltage detectors). The schematic is
shown in Figure 5, with component values selected for a
4.5V undervoltage threshold and a 5.5V overvoltage
threshold. Choose different thresholds by changing the
values of R1, R2, and R3. To prevent chatter at the
output when the supply voltage is close to a threshold,
hysteresis has been added using R4 and R5. Taken
alone, OUTA would provide an active-low undervoltage
ind ic a tion, a nd OUTB would g ive a n a c tive -low
overvoltage indication. Wired-ORing the two outputs
provides an active-high, power-good signal.
whe re I
(the c urre nt s ourc e d b y the re fe re nc e )
REF
s hould not e xc e e d the REF s ourc e c a p a b ility, a nd
s hould b e s ig nific a ntly la rg e r tha n the HYST inp ut
c urre nt.
usually appropriate. If 2.4MΩ is chosen for R2 (I
0.5µA), the e q ua tion for R1 a nd
approximated as:
I
va lue s b e twe e n 0.1µA a nd 4µA a re
REF
=
REF
7/1–MAX984
V
HB
c a n b e
R1 (kΩ) = V (mV)
HB
Whe n hyste re sis is obta ine d in this ma nne r for the
MAX982/MAX9_3, the same hysteresis applies to both
comparators.
Hysteresis (MAX972/MAX9_4)
Hysteresis can be implemented with any comparator
using positive feedback, as shown in Figure 4. This
approach generally draws more current than circuits
using the HYST pin on the MAX9_1/MAX982/MAX9_3,
and the high feedback impedance slows hysteresis. In
addition, because the output does not source current,
any increase in the upper threshold is dependent on
the load or pull-up resistor on the output.
The design procedure is as follows:
1) Choose the required hysteresis level and calculate
values for R4 and R5 according to the formulas in
the Hysteresis (MAX9_1/MAX982/MAX9_3) section.
In this example, ±5mV of hysteresis has been added
at the comparator input (V = V / 2). This means
H
HB
that the hysteresis apparent at V will be larger
because of the input resistor divider.
IN
10 ______________________________________________________________________________________
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
2) Select R1. The leakage current into INB- is normally
under 1nA, so the current through R1 should exceed
100nA for the thresholds to be accurate. R1 values
up to about 10MΩ can be used, but values in the
100kΩ to 1MΩ range are usually easier to deal with.
In this example, choose R1 = 294kΩ.
V
V
UTH
= 5.5V
= 4.5V
V
IN
OTH
+5V
R3
1M
7
1M
V+
3) Ca lc ula te R2 + R3. The ove rvolta g e thre s hold
3
INA+
s hould b e 5.5V whe n V is ris ing . The d e s ig n
IN
OUTA
1
equation is as follows:
V
OTH
+ V
H
5
6
HYST
REF
R2 + R3 = R1 ×
− 1
V
R2
62.2k
REF
R5
10k
5.5
(1.182 + 0.005)
= 294k ×
− 1
R4
2.4M
OUTB
8
POWER GOOD
= 1.068MΩ
4
INB-
2
4) Calculate R2. The undervoltage threshold should be
R1
294k
MAX9_3
4.5V when V is falling. The design equation is as
V-
IN
follows:
(V
− V )
H
REF
V
R2 = (R1 + R2 + R3) ×
− R1
UTH
(1.182 − 0.005)
= (294k + 1.068M) ×
= 62.2kΩ
− 294k
4.5
Figure 5. Window Detector
Ba t t e ry S w it c h o ve r Circ u it
The switc hove r from line -p owe re d DC to a b a c kup
battery is often accomplished with diodes. But this
simple method is sometimes unacceptable, due to the
voltage drop and associated power loss across the
d iod e in s e rie s with the b a tte ry. Fig ure 6’s c irc uit
Choose R2 = 61.9kΩ (1% standard value).
5) Calculate R3:
R3 = (R2 + R3) − R2
= 1.068M − 61.9k
= 1.006MΩ
re p la c e s the d iod e with
a P-c ha nne l MOSFET
controlled by one of the MAX9_3 comparator outputs.
Choose R3 = 1MΩ (1% standard value)
When the DC wall adapter drops below 4V (determined
b y R1 a nd R2), OUTA g oe s low, turning on Q1.
Comparator B is used to measure the battery voltage,
and gives a “low-battery” indication when the battery
drops below 3.6V.
6) Verify the resistor values. The equations are as
follows, evaluated for the above example:
Overvoltage Threshold :
(R1 + R2 + R3)
V
= (V
+ V ) ×
OTH
REF H
R1
Le ve l S h ift e r
Figure 7 shows a circuit to shift from bipolar ±5V inputs
to s ing le -e nd e d +5V outp uts . The 10kΩ re s is tors
protect the comparator inputs, and do not materially
affect the circuit’s operation.
= 5.474V
Undervoltage Threshold :
(R1 + R2 + R3)
V
= (V
− V ) ×
UTH
REF H
(R1 + R2)
= 4.484V
R5
R4
where the hysteresis voltage V = V
×
REF
.
H
______________________________________________________________________________________ 11
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
+5V
+3.3V
WALL
ADAPTER
3
V+
+9V DC
STEP-DOWN
10k
MAX974
MAX984
REGULATOR
5
INA+
+3.3V
V
INA
Q1
LOGIC
SUPPLY
OUTA
2
1
4
7
INA-
1M
10k
7
INB+
V
INB
V+
BATTERY
(4 CELLS)
OUTB
MAX973
MAX983
10k
6
INB-
953k
470k
4
INB-
10k
10k
11 INC+
OUTB
8
V
INC
LOW BATT
OUTC 16
OUTD 15
10 INC-
13 IND+
1
3
OUTA
INA+
R1
110k
DC OK
V
IND
REF
6
5
12 IND-
8
REF
N.C.
20k
R2
HYST
47k
V-
GND
14
V-
2
2.4M
9
-5V
Figure 7. Level Shifter: ±5V Input to Single-Ended +3.3V
Output
7/1–MAX984
Figure 6. Battery Switchover Circuit
__________________________________________________________P in Co n fig u ra t io n s
TOP VIEW
GND
1
2
3
4
8
OUTA
8
OUTA
8
1
2
3
4
1
2
3
4
OUT
V+
OUTB
V+
OUTB
V+
V-
IN+
IN-
7
6
5
V-
INA+
INA-
7
6
5
V-
INA+
INB+
7
6
5
MAX971
MAX981
MAX972
MAX982
REF
HYST
INB+
INB-
REF
HYST
DIP/SO/µMAX
DIP/SO/µMAX
DIP/SO/µMAX
12 ______________________________________________________________________________________
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
_____________________________________________P in Co n fig u ra t io n s (c o n t in u e d )
TOP VIEW
OUTB
OUTA
V+
1
2
3
4
5
6
7
8
16
OUTC
15 OUTD
14 GND
13 IND+
12 IND-
11 INC+
10 INC-
OUTA
1
2
3
4
8
OUTB
V+
V-
INA+
INB-
7
6
5
INA-
INA+
INB-
INB+
REF
MAX974
MAX984
MAX973
MAX983
REF
HYST
DIP/SO/µMAX
9
V-
DIP/Narrow SO
__________________________________________Ord e rin g In fo rm a t io n (c o n t in u e d )
PART
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
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
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
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 Plastic DIP
8 SO
PART
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
0°C to +70°C
PIN-PACKAGE
8 Plastic DIP
8 SO
MAX981CPA
MAX981CSA
MAX981CUA
MAX981EPA
MAX981ESA
MAX982CPA
MAX982CSA
MAX982CUA
MAX982EPA
MAX982ESA
MAX983CPA
MAX983CSA
MAX983CUA
MAX983EPA
MAX983ESA
MAX984CPE
MAX984CSE
MAX984EPE
MAX984ESE
MAX971EPA
MAX971ESA
MAX971MJA
MAX972CPA
MAX972CSA
MAX972CUA
MAX972C/D
MAX972EPA
MAX972ESA
MAX972MJA
MAX973CPA
MAX973CSA
MAX973CUA
MAX973C/D
MAX973EPA
MAX973ESA
MAX973MJA
MAX974CPE
MAX974CSE
MAX974C/D
MAX974EPE
MAX974ESE
MAX974MJE
8 µMAX
8 CERDIP**
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
0°C to +70°C
8 Plastic DIP
8 SO
0°C to +70°C
8 µMAX
0°C to +70°C
Dice*
8 µMAX
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
0°C to +70°C
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 CERDIP**
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
0°C to +70°C
8 µMAX
0°C to +70°C
8 µMAX
8 Plastic DIP
8 SO
0°C to +70°C
Dice*
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
0°C to +70°C
8 Plastic DIP
8 SO
16 Plastic DIP
16 Narrow SO
16 Plastic DIP
16 Narrow SO
8 CERDIP**
16 Plastic DIP
16 Narrow SO
Dice*
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
16 Plastic DIP
16 Narrow SO
16 CERDIP**
*
Dice are tested at T = +25°C, DC parameters only.
A
** Contact factory for availability and processing to MIL-STD-883.
______________________________________________________________________________________ 13
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
___________________Ch ip In fo rm a t io n
MAX971/MAX972/MAX973
TRANSISTOR COUNT: 164
SUBSTRATE CONNECTED TO V+
MAX974
TRANSISTOR COUNT: 267
SUBSTRATE CONNECTED TO V+
7/1–MAX984
14 ______________________________________________________________________________________
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
7/1–MAX984
_______________________________________________________P a c k a g e In fo rm a t io n
INCHES
MILLIMETERS
DIM
MIN
0.036
MAX
0.044
0.008
0.014
0.007
0.120
0.120
MIN
0.91
0.10
0.25
0.13
2.95
2.95
MAX
1.11
0.20
0.36
0.18
3.05
3.05
A
C
A1 0.004
α
A
B
C
D
E
e
0.010
0.005
0.116
0.116
0.101mm
0.004 in
e
B
A1
L
0.0256
0.65
H
L
0.188
0.016
0°
0.198
0.026
6°
4.78
0.41
0°
5.03
0.66
6°
α
21-0036D
E
H
8-PIN µMAX
MICROMAX SMALL-OUTLINE
PACKAGE
D
INCHES
MILLIMETERS
DIM
MIN
MAX
0.069
0.010
0.019
0.010
0.157
MIN
1.35
0.10
0.35
0.19
3.80
MAX
1.75
0.25
0.49
0.25
4.00
A
0.053
D
A1 0.004
B
C
E
e
0.014
0.007
0.150
0°-8°
A
0.101mm
0.004in.
0.050
1.27
e
H
L
0.228
0.016
0.244
0.050
5.80
0.40
6.20
1.27
A1
C
B
L
INCHES
MILLIMETERS
DIM PINS
Narrow SO
SMALL-OUTLINE
PACKAGE
MIN MAX
MIN
MAX
5.00
8.75
8
0.189 0.197 4.80
D
D
D
E
H
14 0.337 0.344 8.55
16 0.386 0.394 9.80 10.00
21-0041A
(0.150 in.)
______________________________________________________________________________________ 15
Ult ra -Lo w -P o w e r, Op e n -Dra in ,
S in g le /Du a l-S u p p ly Co m p a ra t o rs
__________________________________________P a c k a g e In fo rm a t io n (c o n t in u e d )
INCHES
MILLIMETERS
DIM
E
MIN
MAX
0.200
–
MIN
–
MAX
5.08
–
A
–
E1
D
A1 0.015
A2 0.125
A3 0.055
0.38
3.18
1.40
0.41
1.14
0.20
0.13
7.62
6.10
2.54
7.62
–
0.175
0.080
0.022
0.065
0.012
0.080
0.325
0.310
–
4.45
2.03
0.56
1.65
0.30
2.03
8.26
7.87
–
A3
A2
A1
A
L
B
0.016
B1 0.045
0.008
D1 0.005
0.300
E1 0.240
0.100
eA 0.300
C
0° - 15°
E
C
e
e
B1
eA
eB
–
–
B
eB
L
–
0.400
0.150
10.16
3.81
0.115
2.92
D1
INCHES
MILLIMETERS
PKG. DIM
PINS
Plastic DIP
PLASTIC
DUAL-IN-LINE
PACKAGE
(0.300 in.)
MIN
MAX MIN
MAX
8
P
P
P
P
P
N
D
D
D
D
D
D
0.348 0.390 8.84
9.91
14
16
18
20
24
0.735 0.765 18.67 19.43
0.745 0.765 18.92 19.43
0.885 0.915 22.48 23.24
1.015 1.045 25.78 26.54
1.14 1.265 28.96 32.13
21-0043A
7/1–MAX984
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.
16 __________________Ma x im In t e g ra t e d P ro d u c t s , 1 2 0 S a n Ga b rie l Drive , S u n n yva le , CA 9 4 0 8 6 (4 0 8 ) 7 3 7 -7 6 0 0
© 1995 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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