General-Purpose Comparators
ADCMP370/ADCMP371
VCC
ADCMP370
OUT
IN+
IN–
04745-0-001
2.25 V to 5.5 V operating voltage range
Low power consumption (4 µA)
Output stages
ADCMP370: open-drain, high voltage (22 V tolerance)
ADCMP371: push-pull
50 nA input bias current
150 nA input offset current
9 mV input offset voltage
Rail-to-rail common-mode input range
Specified over –40°C to +85°C temperature range
5-lead SC70 package
FUNCTIONAL BLOCK DIAGRAMS
GND
Figure 1.
APPLICATIONS
Voltage detectors
Battery management systems
A/D converters
Low voltage applications
Battery-powered electronics
Portable equipment
VCC
ADCMP371
VCC
IN+
OUT
IN–
GENERAL DESCRIPTION
The ADCMP370/ADCMP371 are general-purpose comparators
with input offset voltages of 9 mV (max) and low power
consumption, which make them ideal for battery-powered
portable equipment.
GND
04745-0-002
FEATURES
Figure 2.
The ADCMP371 has a push-pull output stage, while the
ADCMP370 has an open-drain output. The inputs on both
parts and the output on the ADCMP370 can tolerate voltages
up to 22 V, making them suitable for use as voltage detectors in
portable equipment.
They are available in space-efficient 5-lead SC70 packaging.
Rev. 0
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However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703
© 2004 Analog Devices, Inc. All rights reserved.
ADCMP370/ADCMP371
TABLE OF CONTENTS
Specifications..................................................................................... 3
Applications........................................................................................9
Absolute Maximum Ratings............................................................ 4
Basic Comparator..........................................................................9
ESD Caution.................................................................................. 4
Adding Hysteresis..........................................................................9
Pin Configuration and Function Descriptions............................. 5
Outline Dimensions ....................................................................... 11
Typical Performance Characteristics ............................................. 6
Ordering Guide .......................................................................... 11
REVISION HISTORY
10/04—Revision 0: Initial Version
Rev. 0 | Page 2 of 12
ADCMP370/ADCMP371
SPECIFICATIONS
VCC = Full Operating Range, TA = −40°C to +85°C, unless otherwise noted.
Table 1.
Parameter
SUPPLY
VCC Operating Voltage Range
Supply Current
COMMON-MODE INPUT RANGE
INPUT OFFSET VOLTAGE
INPUT OFFSET VOLTAGE AVERAGE DRIFT
INPUT BIAS CURRENT
INPUT OFFSET CURRENT
OUT VOLTAGE LOW
OUT VOLTAGE HIGH (ADCMP371)
OUT LEAKAGE CURRENT (ADCMP370)
Output Rise Time
Output Fall Time
TIMING
Propagation Delay
Min
Typ
2.25
4
0
Max
Unit
Test Conditions/Comments
5.5
7
VCC
9
V
µA
V
mV
µV/°C
nA
nA
V
VIN = VCC/2
VCM = 0 V
VIN = VCC/2
VIN = VCC/2
IN+ < IN−, ISINK = 1.2 mA
5
50
150
0.4
0.8 VCC
V
IN+ > IN−, ISOURCE = 500 µA
30
45
µA
ns
ns
IN+ > IN−, OUT = 22 V
COUT = 15 pF
COUT = 15 pF
5
2
µs
µs
Input overdrive = 10 mV
Input overdrive = 100 mV
1
Rev. 0 | Page 3 of 12
ADCMP370/ADCMP371
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 2.
Parameter
VCC
IN+, IN−
OUT (ADCMP370)
OUT (ADCMP371)
Operating Temperature Range
Storage Temperature Range
θJA Thermal Impedance, SC70
Lead Temperature
Soldering (10 sec)
Vapor Phase (60 sec)
Infrared (15 sec)
Rating
−0.3 V to +6 V
−0.3 V to +25 V
−0.3 V to +25 V
−0.3 V to +VCC + 0.3 V
−40°C to +85°C
−65°C to +150°C
146°C/W
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only and functional operation of the device at these or
any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
300°C
215°C
220°C
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the
human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. 0 | Page 4 of 12
ADCMP370/ADCMP371
IN+
1
GND
2
IN–
3
5
VCC
4
OUT
ADCMP370/
ADCMP371
04745-0-003
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 3. Pin Configuration
Table 3. Pin Function Descriptions
Pin No.
1
2
3
4
5
Mnemonic
IN+
GND
IN–
OUT
VCC
Description
Noninverting Input.
Ground.
Inverting Input.
Comparator Output. Open-drain for ADCMP370. Push-pull for ADCMP371.
Power Supply.
Rev. 0 | Page 5 of 12
ADCMP370/ADCMP371
TYPICAL PERFORMANCE CHARACTERISTICS
30
3.0
25
PROPAGATION DELAY (µs)
2.5
15
10
5
tPHL
2.0
1.5
tPLH
1.0
0.5
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
–40
04745-0-006
–5
5.5
CM I/P (V)
25
85
TEMPERATURE (°C)
125
04745-0-013
OFFSET (mV)
20
Figure 7. Propagation Delay vs. Temperature
Figure 4. Input Offset vs. Common-Mode Input Voltage
4.0
4.5
4.0
3.5
3.5
SUPPLY CURRENT (µA)
3.0
2.5
tPLH +125°C
2.0
tPLH +25°C
1.5
1.0
3.0
–40°C
+25°C
2.5
+125°C
2.0
1.5
1.0
0.5
0
10
20
30
40
50
60
70
80
90
100 110 120 130
INPUT OVERDRIVE (mV)
04745-0-007
0.5
0
Figure 5. Propagation Delay vs. Input Overdrive (Low to High)
1
2
3
4
SUPPLY VOLTAGE (V)
5
6
04745-0-021
PROPAGATION DELAY (µs)
tPLH –40°C
Figure 8. Supply Current vs. Supply Voltage (Output Low)
4.0
6
3.5
SUPPLY CURRENT (µA)
4
tPHL +125°C
tPHL +25°C
tPHL –40°C
2
1
0
10
3.0
–40°C
2.5
+125°C
+25°C
2.0
1.5
1.0
0.5
20
30
40
50 60 70 80 90 100 110 120 130
INPUT OVERDRIVE (mV)
0
1
2
3
4
SUPPLY VOLTAGE (V)
5
Figure 9. Supply Current vs. Supply Voltage (Output High)
Figure 6. Propagation Delay vs. Input Overdrive (High to Low)
Rev. 0 | Page 6 of 12
6
04745-0-015
3
04745-0-008
PROPAGATION DELAY (µs)
5
ADCMP370/ADCMP371
1000
900
800
700
700
VCC = 2.25V
600
I BIAS (nA)
OUTPUT LOW VOLTAGE (mV)
900
500
400
500
300
VCC = 3.3V
VCC = 5.5V
300
VCC = 5V
200
100
0
1
2
3
4
5
SINK CURRENT (mA)
–100
5.1
5.2
5.3
5.4
5.5
VIN (V)
04745-0-023
0
04745-0-016
100
Figure 13. Input Bias Current vs. Input Voltage
Figure 10. Output Low Voltage vs. Sink Current
–1.0
1.20
–1.2
1.15
–1.4
1.10
HYSTERESIS (mV)
OFFSET (mV)
–1.6
–1.8
–2.0
–2.2
VCC = 2.25V
VCC = 5V
VCC = 3.3V
–2.4
1.05
1.00
0.95
0.90
–2.6
25
85
TEMPERATURE (°C)
125
04745-0-020
–3.0
–40
0.80
2.25
2.75
3.25
3.75
4.25
VCC (V)
4.75
5.25
5.50
04745-0-027
0.85
–2.8
Figure 14. Hysteresis vs. Supply Voltage
Figure 11. Input Offset vs. Temperature
3.0
300
2.5
200
2.0
HYSTERESIS (mV)
250
150
IOUT = 1mA
100
1.5
1.0
VCC = 5V
50
0
50
TEMPERATURE (°C)
100
150
0
–50
0
50
TEMPERATURE (°C)
100
Figure 15. Hysteresis vs. Temperature
Figure 12. Output Low Voltage vs. Temperature
Rev. 0 | Page 7 of 12
150
04745-0-028
0
–50
0.5
04745-0-022
OUTPUT LOW VOLTAGE (mV)
IOUT = 2mA
ADCMP370/ADCMP371
1
CH1 = (IN–) – IN+
1
CH1 = (IN–) – IN+
CH2 = OUT
CH2 = OUT
CH2 2.00V/DIV
TIMEBASE: 3.00µs/DIV
CH1 100mV/DIV CH2 2.00V/DIV
TIMEBASE: 1.00µs/DIV
Figure 17. Propagation Delay Timing 100 mV Overdrive
Figure 16. Propagation Delay Timing 10 mV Overdrive
Rev. 0 | Page 8 of 12
04745-0-030
CH1 10mV/DIV
2
04745-0-029
2
ADCMP370/ADCMP371
APPLICATIONS
BASIC COMPARATOR
The upper input threshold level is given by
In its most basic configuration, a comparator can be used to
convert an analog input signal to a digital output signal. The
analog signal on IN+ is compared to the voltage on IN− and the
voltage at OUT is either high or low, depending on whether
IN+ is at a higher or lower potential than IN−, respectively.
The ADCMP370 and ADCMP371 have different digital output
structures. The ADCMP370 has an open-drain output stage
which requires an external resistor to pull OUT to the logic
high voltage level when the output transistor is switched off.
This voltage level can be as high as 22 V. The same 22 V
tolerance applies also to the inputs of the comparators. The
pull-up resistor should be large enough to avoid excessive
power dissipation, but small enough to switch logic levels
reasonably quickly when the comparator output is connected to
other digital circuitry. A suitable value would be between 1 kΩ
and 10 kΩ. The ADCMP371 has a push-pull output stage, which
has an internal PMOS pull-up and therefore doesn’t require an
external resistor. Faster switching speeds between low and high
rails are possible, but the logic high level is limited to VCC.
VIN_HI =
VREF (R1 + R2 ) − VCC R1
R2
The lower input threshold level is given by
VIN_LO =
VREF (R1 + R2 )
R2
The hysteresis is the difference between these voltage levels and
is given by
∆VIN =
VCC R1
R2
In the example in Figure 19, resistors R1 and R2 are chosen to
give 1 V hysteresis about the reference of 2.5 V, with VCC = 5 V.
It’s important that RPULL-UP << RLOAD so that the output high
voltage isn’t pulled below VCC.
VCC = 5V
ADM331
ADCMP370
VCC
V+
VREF = 2.5V
ADM331
ADCMP370
IN–
RLOAD
IN+
VIN
OUT
RPULLUP = 5kΩ
OUT
R1 = 200kΩ
VIN
VREF
R2 = 1MΩ
VOUT
VOUT
V+
0V
VIN_LO VIN_HI
= 2V
= 3V
VIN
04745-0-017
t
VIN
Figure 19. Noninverting Comparator Configuration with Hysteresis
Figure 18. Basic Comparator and Input and Output Signals
With the inverting configuration, the upper and lower
switching thresholds are
ADDING HYSTERESIS
To prevent oscillations at the output caused by noise or slowly
moving signals passing the switching threshold, positive
feedback can be used to add hysteresis to the differential input.
For the noninverting configuration, shown in Figure 19, two
resistors are used to create different switching thresholds,
depending on whether the input signal is increasing or
decreasing in magnitude. When the input voltage is increasing,
the threshold is above VREF; and when it’s decreasing, the
threshold is below VREF.
Rev. 0 | Page 9 of 12
VIN_HI =
VCC R2
(R1 || R3) + R2
VIN_LO =
VCC (R2 || R3 )
R1 + (R2 || R3 )
04745-0-018
VREF
ADCMP370/ADCMP371
VCC = 5V
ADCMP371
R1 = 1MΩ
VCC
IN+
OUT
RLOAD
R3 = 1MΩ
R2 = 1MΩ
VOUT HIGH:
VOUT LOW:
VCC
R1
VCC
R3
R1
VIN_LO
VIN_HI
R2
R2
R3
VOUT
VIN_LO VIN_HI
= 1.67V = 3.33V
VIN
Figure 20. Noninverting Comparator Configuration with Hysteresis
Rev. 0 | Page 10 of 12
04745-0-019
VIN
IN–
ADCMP370/ADCMP371
OUTLINE DIMENSIONS
2.00 BSC
5
4
1.25 BSC
2.10 BSC
1
2
3
PIN 1
0.65 BSC
1.00
0.90
0.70
1.10 MAX
0.22
0.08
0.30
0.15
0.10 MAX
SEATING
PLANE
0.46
0.36
0.26
0.10 COPLANARITY
COMPLIANT TO JEDEC STANDARDS MO-203AA
Figure 21. 5-Lead Thin Shrink Small Outline Transistor Package [SC70]
(KS-5)
Dimensions shown in millimeters
ORDERING GUIDE
Model
ADCMP370AKS-REEL
ADCMP370AKS-REEL7
ADCMP371AKS-REEL
ADCMP371AKS-REEL7
Temperature Range
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
Package Description
5-Lead SC70
5-Lead SC70
5-Lead SC70
5-Lead SC70
Rev. 0 | Page 11 of 12
Package Option
KS-5
KS-5
KS-5
KS-5
Branding
M1F
M1F
M1G
M1G
ADCMP370/ADCMP371
NOTES
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D04745-0-10/04(0)
Rev. 0 | Page 12 of 12