General-Purpose Comparators
FEATURES
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
APPLICATIONS
Voltage detectors
Battery management systems
A/D converters
Low voltage applications
Battery-powered electronics
Portable equipment
ADCMP370/ADCMP371
FUNCTIONAL BLOCK DIAGRAMS
V
CC
ADCMP370
IN+
IN–
GND
Figure 1.
V
CC
ADCMP371
IN+
IN–
V
CC
OUT
04745-0-001
OUT
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.
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.
GND
Figure 2.
04745-0-002
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable.
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
Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
www.analog.com
ADCMP370/ADCMP371
TABLE OF CONTENTS
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 4
ESD Caution.................................................................................. 4
Pin Configuration and Function Descriptions............................. 5
Typical Performance Characteristics ............................................. 6
REVISION HISTORY
10/04—Revision 0: Initial Version
Applications........................................................................................9
Basic Comparator..........................................................................9
Adding Hysteresis..........................................................................9
Outline Dimensions ....................................................................... 11
Ordering Guide .......................................................................... 11
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 Min Typ Max Unit Test Conditions/Comments
SUPPLY
VCC Operating Voltage Range 2.25 5.5 V
Supply Current
COMMON-MODE INPUT RANGE 0 V
INPUT OFFSET VOLTAGE 9 mV VIN = VCC/2
INPUT OFFSET VOLTAGE AVERAGE DRIFT 5 µV/°C VCM = 0 V
INPUT BIAS CURRENT 50 nA VIN = VCC/2
INPUT OFFSET CURRENT 150 nA VIN = VCC/2
OUT VOLTAGE LOW 0.4 V
OUT VOLTAGE HIGH (ADCMP371) 0.8 V
OUT LEAKAGE CURRENT (ADCMP370) 1 µA
Output Rise Time 30 ns C
Output Fall Time 45 ns C
TIMING
Propagation Delay
4 7 µA
CC
CC
V
V
IN+ < IN−, I
IN+ > IN−, I
SINK
SOURCE
= 1.2 mA
= 500 µA
IN+ > IN−, OUT = 22 V
= 15 pF
OUT
= 15 pF
OUT
5 µs Input overdrive = 10 mV
2 µs Input overdrive = 100 mV
Rev. 0 | Page 3 of 12
ADCMP370/ADCMP371
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 2.
Parameter Rating
V
CC
IN+, IN− −0.3 V to +25 V
OUT (ADCMP370)
OUT (ADCMP371)
Operating Temperature Range
Storage Temperature Range
θ
Thermal Impedance, SC70 146°C/W
JA
Lead Temperature
Soldering (10 sec) 300°C
Vapor Phase (60 sec) 215°C
Infrared (15 sec) 220°C
−0.3 V to +6 V
−0.3 V to +25 V
−
0.3 V to +VCC
−40°C to +85°C
−65°C to +150°C
+ 0.3 V
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.
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
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
V
IN+
1
ADCMP370/
2
GND
ADCMP371
3
IN–
Figure 3. Pin Configuration
Table 3. Pin Function Descriptions
Pin No. Mnemonic Description
1 IN+ Noninverting Input.
2 GND Ground.
3 IN– Inverting Input.
4 OUT Comparator Output. Open-drain for ADCMP370. Push-pull for ADCMP371.
5 V
CC
Power Supply.
5
CC
4
OUT
04745-0-003
Rev. 0 | Page 5 of 12
ADCMP370/ADCMP371
TYPICAL PERFORMANCE CHARACTERISTICS
30
25
20
15
10
OFFSET (mV)
5
0
–5
0 5.51.0 1.5 2.0 4.5 5.0
CM I/P (V)
3.5 4.02.5 3.00.5
Figure 4. Input Offset vs. Common-Mode Input Voltage
4.5
4.0
t
–40°C
PLH
3.5
3.0
2.5
2.0
1.5
1.0
PROPAGATION DELAY (µs)
0.5
0
10 20 30 40 50 60 70 80 90 100 110 120 130
t
+125°C
PLH
t
+25°C
PLH
INPUT OVERDRIVE (mV)
Figure 5. Propagation Delay vs. Input Overdrive (Low to High)
04745-0-006
04745-0-007
3.0
2.5
t
PHL
2.0
1.5
1.0
PROPAGATION DELAY (µs)
0.5
t
PLH
0
–4025 851
TEMPERATURE (°C)
25
04745-0-013
Figure 7. Propagation Delay vs. Temperature
4.0
3.5
3.0
2.5
2.0
1.5
SUPPLY CURRENT (µA)
1.0
0.5
0
1
+25°C
–40°C
SUPPLY VOLTAGE (V)
+125°C
5432 6
04745-0-021
Figure 8. Supply Current vs. Supply Voltage (Output Low)
6
5
4
t
+125°C
3
t
+25°C
PHL
2
PROPAGATION DELAY (µs)
1
0
10 20 30 40 50 60 70 80 90 100 110 120 130
INPUT OVERDRIVE (mV)
PHL
t
–40°C
PHL
Figure 6. Propagation Delay vs. Input Overdrive (High to Low)
04745-0-008
Rev. 0 | Page 6 of 12
4.0
3.5
3.0
2.5
+25°C
2.0
1.5
SUPPLY CURRENT (µA)
1.0
0.5
0
1
SUPPLY VOLTAGE (V)
–40°C
432
5
Figure 9. Supply Current vs. Supply Voltage (Output High)
+125°C
6
04745-0-015
ADCMP370/ADCMP371
1000
900
800
700
600
500
400
300
OUTPUT LOW VOLTAGE (mV)
200
100
VCC = 3.3V
0
05321
SINK CURRENT (mA)
Figure 10. Output Low Voltage vs. Sink Current
V
4
CC
V
CC
= 2.25V
= 5V
04745-0-016
900
700
500
I BIAS (nA)
300
100
–100
5.1
VCC = 5.5V
VIN(V)
Figure 13. Input Bias Current vs. Input Voltage
5.55.2 5.45.3
04745-0-023
–1.0
–1.2
–1.4
–1.6
–1.8
–2.0
VCC = 2.25V
–2.2
OFFSET (mV)
VCC = 5V
–2.4
–2.6
–2.8
–3.0
–40 25 125
= 3.3V
V
CC
TEMPERATURE (°C)
85
Figure 11. Input Offset vs. Temperature
300
= 2mA
I
OUT
250
200
150
I
100
OUTPUT LOW VOLTAGE (mV)
50
OUT
= 1mA
04745-0-020
1.20
1.15
1.10
1.05
1.00
0.95
HYSTERESIS (mV)
0.90
0.85
0.80
2.25 2.75 3.25 3.75 4.25 4.75 5.25 5.50
(V)
V
CC
Figure 14. Hysteresis vs. Supply Voltage
3.0
2.5
2.0
1.5
1.0
HYSTERESIS (mV)
0.5
VCC = 5V
04745-0-027
0
–50 100 150
500
TEMPERATURE (°C)
Figure 12. Output Low Voltage vs. Temperature
04745-0-022
Rev. 0 | Page 7 of 12
0
–50 0 50 100 150
TEMPERATURE (°C)
Figure 15. Hysteresis vs. Temperature
04745-0-028
ADCMP370/ADCMP371
CH1 = (IN–) – IN+
1
1
CH1 = (IN–) – IN+
CH2 = OUT
2
CH1 10mV/DIV CH2 2.00V/DIV TIMEBASE: 3.00µs/DIV
Figure 16. Propagation Delay Timing 10 mV Overdrive
04745-0-029
CH2 = OUT
2
CH1 100mV/DIV TIMEBASE: 1.00µs/DIV
CH2 2.00V/DIV
Figure 17. Propagation Delay Timing 100 mV Overdrive
04745-0-030
Rev. 0 | Page 8 of 12
ADCMP370/ADCMP371
(
(
(
)
APPLICATIONS
BASIC COMPARATOR
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 k
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 V
V
CC
V+
ADM331
ADCMP370
V
IN
V
REF
OUT
Ω
.
CC
The upper input threshold level is given by
)
V
IN_HI
V
REF
=
R2
−+
R1VR2R1
CC
The lower input threshold level is given by
R2R1+
V
IN_LO
V
REF
=
R2
)
The hysteresis is the difference between these voltage levels and
is given by
V
R1
V =∆
CC
R2
IN
In the example in Figure 19, resistors R1 and R2 are chosen to
R
PULLUP
CC
R
LOAD
= 5 V.
= 5kΩ
give 1 V hysteresis about the reference of 2.5 V, with V
It’s important that R
voltage isn’t pulled below V
V
REF
V
IN
= 2.5V
R1 = 200kΩ
IN–
IN+
<< R
PULL-UP
CC
ADM331
ADCMP370
R2 = 1MΩ
so that the output high
LOAD
.
V
= 5V
CC
OUT
V
V+
V
REF
0V
Figure 18. Basic Comparator and Input and Output Signals
OUT
t
V
IN
04745-0-017
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 V
threshold is below V
; and when it’s decreasing, the
REF
.
REF
Rev. 0 | Page 9 of 12
V
OUT
V
V
V
IN_LO
IN_HI
= 2V
= 3V
Figure 19. Noninverting Comparator Configuration with Hysteresis
IN
With the inverting configuration, the upper and lower
switching thresholds are
V
V
CC
=
IN_HI
()
||
CC
=
IN_LO
()
+
R2R3R1
+
R3R2||||V
R3R2R1
R2
V
04745-0-018
ADCMP370/ADCMP371
V
VCC = 5V
R1 = 1M
IN
Ω
IN+
IN–
R2 = 1M
ADCMP371
Ω
V
V
V
IN_HI
V
OUT
OUT
CC
R3 = 1M
HIGH:
R2
V
IN_LO
= 1.67V
R3R1
V
V
= 3.33V
Ω
IN_LO
IN_HI
V
CC
V
LOW:
OUT
V
CC
R1
R3R2
V
IN
Figure 20. Noninverting Comparator Configuration with Hysteresis
OUT
R
LOAD
04745-0-019
Rev. 0 | Page 10 of 12
ADCMP370/ADCMP371
OUTLINE DIMENSIONS
2.00 BSC
0.30
0.15
45
0.65 BSC
2.10 BSC
1.10 MAX
SEATING
PLANE
0.22
0.08
0.46
0.36
0.26
1.25 BSC
1.00
0.90
0.70
0
.
0
1
123
PIN 1
M
X
A
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 Temperature Range Package Description Package Option Branding
ADCMP370AKS-REEL −40°C to +85°C 5-Lead SC70 KS-5 M1F
ADCMP370AKS-REEL7 −40°C to +85°C 5-Lead SC70 KS-5 M1F
ADCMP371AKS-REEL −40°C to +85°C 5-Lead SC70 KS-5 M1G
ADCMP371AKS-REEL7 −40°C to +85°C 5-Lead SC70 KS-5 M1G
Rev. 0 | Page 11 of 12
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
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