Single Comparator with
Accurate Reference Output
Preliminary Technical Data
ADCMP394
Rev.
PrC
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
www.analog.com
Fax: 781.461.3113 ©2014 Analog Devices, Inc. All rights reserved.
FEATURES
High accuracy reference output voltage: 1 V±0.8%
Single supply voltage operation: 2.3V to 5.5V
Rail-to-rail, common-mode input voltage range
Low input offset voltage,
V
OFFSET: 1mV Typical
Guarantees comparator output logic low from 0.9V VCC to
UVLO
Operating temperature range: -40°C to +125°C
Package type:
8-Narrow Body SOIC
APPLICATIONS
Battery Management/Monitoring
Power Supply Detection
Window Comparator
Threshold detectors/discriminators
Microprocessor systems
GENERAL DESCRIPTION
The ADCMP394 is a single rail-to-rail input low power
comparators ideal for use in general-purpose applications. The
devices operate from a supply voltage of 2.3V up to 5.5V and draws
minimal amount of current. The single ADCMP394 consumes only
36uA of supply current. The low voltage and low current operation
of the ADCMP394 makes it ideal for battery-powered systems.
The comparators feature a common-mode input voltage range of
200mV beyond rails, an offset voltage of 1mV typical across the full
common-mode range, and an undervoltage lockout (UVLO)
monitor. In addition, the design of the comparators allows a
defined output state upon power-up. The comparators generate a
logic low output while the supply voltage is still below the UVLO
threshold.
The comparators incorporate a 1V ±0.8% buffered reference
voltage. The reference voltage output can directly connect to the
comparator input to serve as the trip value for precise monitoring
and detection of positive voltage. It can also act as an offset when
monitoring negative voltage.
The ADCMP394 is available in an 8-pin Narrow Body SOIC
package. The ADCMP394 is specified to operate over the extended
temperature range of -40°C to +125°C.
F
UNCTIONAL BLOCK DIAG
RAMS
Figure 1 Block Diagrams
REF
ADCMP394
REF
IN+
IN-
VCC
OUT
GND
ADCMP394 Preliminary Technical Data
Rev. PrC | Page 2 of 14
TABLE OF CONTENT
Functional Block Diagrams ...............................................................................................................................................................................................1
Features ............................................................................................................................................................................................................................1
Applications .........................................................................................................................................................................................................................1
General Description ...........................................................................................................................................................................................................1
Specifications .......................................................................................................................................................................................................................3
Absolute Maximum Ratings ..............................................................................................................................................................................................4
Thermal Resistance ........................................................................................................................................................................................................4
ESD Caution ....................................................................................................................................................................................................................4
Pin Configuration and Function Descriptions ...............................................................................................................................................................5
Typical Performance Characteristics ...............................................................................................................................................................................6
Functional Diagrams ....................................................................................................................................................................................................... 10
Theory of Operation ....................................................................................................................................................................................................... 11
Applications ...................................................................................................................................................................................................................... 12
Outline Dimensions ........................................................................................................................................................................................................ 13
Ordering Guide ............................................................................................................................................................................................................ 14
Preliminary Technical Data ADCMP394
Rev. PrC | Page 3 of 14
SPECIFICATIONS
VCC
= 2.3V to 5.5V, T
A
= −40°C to +125°C, unless otherwise noted. Typical values are at T
A
= 25°C.
Table 1.
Parameter Symbol Min Typ Max Unit Test Conditions/Comments
POWER SUPPLY
Supply Voltage VCC 2.3 5.5 V
0.9 UVLO V Guarantees comparator output low
VCC Quiescent Current I
CC
36 43 uA Output in high-Z state
35 40 uA Output low
UNDERVOLTAGE LOCKOUT
VCC Rising UVLO
RISE
2.062 2.162 2.262 V
Hysteresis UVLO
HYS
5 25 50 mV
REFERENCE OUTPUT
Reference Output Voltage V
REF
TBA 1 TBA V I
REF
=±1 mA,
T
A
= −40°C to +85°C
0.994 1 1.008 V I
REF
=±1 mA
COMPARATOR INPUT
Common-mode Input Range V
CMR
-200
VCC+200 mV
Input Offset Voltage V
OFFSET
0.5
0.5
4
TBA
mV
mV
IN+ = IN- = 1V
IN+ = IN- = 1V,
T
A
= -40°C to +85°C
1
1
10
TBA
mV
mV
(-200mV)<V
CMR
<(VCC+200mV)
(-200mV)<V
CMR
<(VCC+200mV),
T
A
=-40°Cto+85°C
Input Offset Current I
OFFSET
10 nA
Input Bias Current I
BIAS
±TBA nA VIN= 0.95 V to 1.05 V
±80 nA (-50mV)<V
CMR
<(VCC+50mV)
Input Hysteresis V
HYST
3
6
TBA
TBA
mV
mV
V
CM
= 1V
(-200mV)<V
CMR
<(VCC+200mV)
COMPARATOR OUTPUT
Output Low Voltage V
OL
0.1 0.3 V VCC=2.3 V; I
SINK
= 2.5 mA
0.01 0.15 V VCC=0.9 V; I
SINK
= 100 uA
Output Leakage Current I
LEAK
200 nA V
OUT
= 0 to 5.5V
COMPARATOR CHARACTERISTICS
Power-Supply Rejection Ratio PSRR 60 80
dB VCC=2.3V to 5.5V
Common-Mode Rejection Ratio CMRR 50 74
dB -200 mV < V
CMR
< VCC+200mV
Voltage Gain
Rise Time
1
Fall Time
1
GV
t
R
t
F
200
1.1
0.15
V/mV
us
us
V
OUT
= 10% to 90% of VCC
V
OUT
= 90% to 10% of VCC
Propagation Delay Input Rising
1
T
PROP_R
4.72 us 10 mV overdrive, VCC=2.3 V
4.85 us 10 mV overdrive, VCC=5.5 V
TBA us 100 mV overdrive, VCC=2.3V
TBA us 100 mV overdrive, VCC=5.5V
Propagation Delay Input Falling
1
T
PROP_F
4.46 us 10 mV overdrive VCC=2.3 V
9.9 us 10 mV overdrive, VCC=5.5 V
TBA us 100 mV overdrive, VCC=2.3V
TBA us 100 mV overdrive, VCC=5.5V
1
Rpull-up = 10 kΩ, C
L
= 50pF
ADCMP394 Preliminary Technical Data
Rev. PrC | Page 4 of 14
ABSOLUTE
MAXIMUM RATINGS
Table 2.
Parameter Rating
VCC pin −0.3 V to +6 V
All IN+ and IN- pins −0.3 V to +6 V
All OUT pins −0.3 V to +6 V
Reference Load Current, I
REF
±1 mA
OUT pins Sink Current, I
SINK
10 mA
Storage Temperature Range -TBA°C to +TBA°C
Operating Temperature Range −40°C to +125°C
Lead Temperature (10 sec) TBA°C
Junction Temperature TBA°C
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.
THERMAL RESISTANCE
Table 3. Thermal Resistance
Package Type θ
JA
Unit
8-Lead Narrow Body SOIC
121
°C/W
ESD CAUTION
Preliminary Technical Data ADCMP394
Rev. PrC | Page 5 of 14
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 2. Pin Configuration—View from the Top of the Die
Table 4. ADCMP394 Pin Function Descriptions
1
Pin No.
SOIC
Pin Name Description
1 GND Device ground
2 NC No connect
3 IN+ Comparator non-inverting input
4 IN- Comparator inverting input
5 NC No connect
6 REF Reference output, can be used to setup comparator threshold
7 VCC Device supply input
8 OUT Comparator output, open-drain
ADCMP394 Preliminary Technical Data
Rev. PrC | Page 6 of 14
TYPICAL PERFORMANCE CHARACTERISTICS
Figure
3
.
Input Offset Voltage vs. Common
-
Mode Voltage
, V
CC
=3.3V
Figure
5
.
Input Offset Voltage vs. Temperature
,
V
CM
=1V
Figure
7
.
Supply Current vs. Supply Voltage @ V
OUT
Low
Figure
4
.
Input Offset Voltage
vs. Supply Vol
tage
, V
CM
=1V
Figure6. Output Voltage
vs. Supply Voltage
, R
PULL-UP
=10kΩ
Figure
8
.
Supply Current vs.
Supply Voltage @ V
OUT
High
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
-0.5 0 0.5 1 1.5 2 2.5 3 3.5
VOS (mV)
VCM (V)
Sample 1 Sample 2 Sample 3
TBD
-0.3
-0.25
-0.2
-0.15
-0.1
-0.05
0
0.05
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120
130
V
OS
, mV
Temperature (°C)
Vcc=2.3V
Vcc=3.3V
Vcc=5.5V
35
37
39
41
43
45
47
49
51
53
2 2.5 3 3.5 4 4.5 5 5.5
Supply Current, I
CC
(uA)
Supply Voltage, V
CC
(V)
25
85
125
-40
TBD
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2
Output Voltage(V)
Supply Voltage(V)
35
37
39
41
43
45
47
49
51
53
2 2.5 3 3.5 4 4.5 5 5.5
Supply Current, I
CC
(uA)
Supply Voltage, V
CC
(V)
25
85
125
-40
IN+ = IN- +10mV
V
CM
= IN- = 1V
Preliminary Technical Data ADCMP394
Rev. PrC | Page 7 of 14
Figure
9
.
Supply Current vs. Temperature @
V
OUT
High
Figure
11
.
Hysteresis vs. Supply Voltage
, V
CM
=1V
Figure
13
.
Propagation Delay vs. Temperature
, Lo
w to High, 10mV Input
Overdrive
Figure
10
.
Supply Current vs. Temperature @
V
OUT
Low
Figure 12. Hysteresis vs. Temperature, V
CM
=1V
Figure
14
.
Propagation Delay vs. Temperature, High
to
Low, 10mV input
Overdrive
35
37
39
41
43
45
47
49
51
53
-50 -25 0 25 50 75 100 125
Supply Current, I
CC
(uA)
Temperature (°C)
2.3V
3.3V
5.5V
TBD
BD
2
3
4
5
6
7
8
-50 -25 0 25 50 75 100 125
Propagation Delay (us)
Temperature (°C)
Vcc=2.3V
Vcc=3.3V
Vcc=5.5V
35
37
39
41
43
45
47
49
51
53
-50 -25 0 25 50 75 100 125
Supply Current, I
CC
(uA)
Temperature (°C)
2.3V
3.3V
5.5V
TBD
0
2
4
6
8
10
12
14
-50 -25 0 25 50 75 100 125
Propagation Delay (us)
Temperature (°C)
Vcc=2.3V
Vcc=3.3V
Vcc=5.5V
ADCMP394 Preliminary Technical Data
Rev. PrC | Page 8 of 14
Figure
15
.
Propagation Delay vs. Input Overdrive Voltage
,Low to High
Figure 17. Output voltage rise time vs. Pull-up Resistance
Figure 19. Reference Voltage vs. Ref Pin Sink Current, V
CC
=3.3V
Figure
16
.
Propagation Delay vs. Input Overdrive Voltage
, High to Low
Figure 18. Output voltage fall time vs. Pull-up Resistance
Figure
20
.
Reference Voltage vs.
Ref pin
Source
Current
, V
CC
=3.3V
0
2
4
6
8
10
12
14
16
18
1 10 100
tR(us)
R
PULL-UP
(kΩ)
1.0026
1.0027
1.0028
1.0029
1.003
1.0031
1.0032
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
VREF (V)
Isink (mA)
1
2
3
4
5
6
7
8
9
10
10 20 30 40 50 60 70 80 90 100
Propagation Delay(us)
Overdrive(mV)
V
CC
=5.5V
V
CC
=3.3V
V
CC
=2.3V
100
110
120
130
140
150
160
170
180
190
200
1 10 100
t
F
(ns)
R
PULL-UP
(kΩ)
1.0018
1.002
1.0022
1.0024
1.0026
1.0028
1.003
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
VREF (V)
Isource (mA)
V
CC
=3.3V
C
L
=50pF
R
PULL-UP
=10kΩ
C
L
=50pF
V
CM
=1V
R
PULL-UP
=10kΩ
C
L
=50pF
V
CM
=1V
V
CC
=3.3V
C
L
=50pF
Preliminary Technical Data ADCMP394
Rev. PrC | Page 9 of 14
Figure 21. Reference Voltage vs. Temperature, V
CC
=3.3V
Figure 22. Output Voltage Low vs. Sink Current, V
CC
=0.9V
Figure 23. Output Voltage Low vs. Sink Current
0.999
0.9995
1
1.0005
1.001
1.0015
1.002
1.0025
1.003
-45 -35 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115
125
Reference Voltage, V
REF
(V)
Temp (°C)
0
100
200
300
400
500
600
700
012345678910
Vout (mV)
Isink (mA)
Vcc=2.3V
Vcc=3.3V
Vcc=5.5V
ADCMP394 Preliminary Technical Data
Rev. PrC | Page 10 of 14
FUNCTIONAL DIAGRAMS
REF
ADCMP394
REF
IN+
IN-
VCC
OUT
GND
Preliminary Technical Data ADCMP394
Rev. PrC | Page 11 of 14
THEORY OF OPERATION
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
Figure XX. Basic Comparator and Input and Output Signals
RAIL-TO-RAIL INPUT (RRI)
Using a CMOS non rail-to-rail input stage (that is a single
differential pair) limits the input voltage to approximately one
gate-source voltage (V
GS
) away from one of the supply lines.
Because V
GS
for normal operation is commonly more than 1V, a
single differential pair, input stage comparator greatly restricts
the allowable input voltage. This can be quite limiting with low
supply voltage supplies. To solve this problem, RRI stages are
designed to allow the input signal to range to the supply
voltages. In the case of the ADCMP396, the inputs continue to
operate 200mV beyond the supply rails.
OPEN-DRAIN OUTPUT
The ADCMP396 has an open-drain output stage that requires
an external resistor to pull OUT to the logic high voltage level
when the output transistor is switched off. 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 is between 1kΩ and 10kΩ.
POWER-UP BEHAVIOR
On power-up, when V
CC
reaches 0.9V, the ADCMP396 is
guaranteed to assert an output low logic. When the voltage on
the V
CC
pin exceeds 2.162V (typ.), the comparator inputs take
control.
CROSSOVER BIAS POINT
Rail-to-rail inputs of this type, in both op amps and
comparators, have a dual front-end design. Certain devices are
active near the V
CC
rail and others are active near the GND. At
some predetermined point in the common-mode range, a
crossover occurs. At this point, normally 0.8V and V
CC
- 0.8V
the direction of the bias current reverses and there are changes
in measured offset voltages.
COMPARATOR HYSTERESIS
The addition of hysteresis, V
H
, to a comparator is often
desirable in a noisy environment, or when the differential input
amplitudes are relatively small or slow moving. The transfer
function for a comparator with hysteresis is shown in Figure
XX. As the input voltage approaches the threshold (0V in Figure
XX) from below the threshold region in a positive direction, the
comparator switches from low to high when the input crosses
+V
H
/2. The new switch threshold becomes –V
H
/2. The
comparator remains in the high state until the threshold, -V
H
/2,
is crossed from below the threshold region in a negative
direction. In this manner, noise or feedback output signals
centered on 0V input cannot cause the comparator to switch
states unless it exceeds the region bounded by ±V
H
/2.
Figure XX. Comparator Hysteresis Transfer Function
ADCMP394 Preliminary Technical Data
Rev. PrC | Page 12 of 14
APPLICATIONS
ADDING HYSTERESIS
For the noninverting configuration, shown in Figure XX, 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
REF
, and when it is decreasing, the
threshold is below V
REF
.
Figure XX. Noninverting Comparator Configuration with Hysteresis
The upper input threshold level is given by
_
=
+
The lower input threshold level is given by
_
=
+
−
The hysteresis is the difference between these voltages levels
∆
=
In the example in Figure XX. resistor R
1
and resistor R
2
are
chosen to give 1V hysteresis about the reference of 2.5V, with
V
CC
= 5V.
Preliminary Technical Data ADCMP394
Rev. PrC | Page 13 of 14
OUTLINE DIMENSIONS
Figure 21. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body (R-8)
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
COMPLIANT TO JEDEC STANDARDS MS-012-AA
012407-A
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
0.50 (0.0196)
0.25 (0.0099) 45°
8°
0°
1.75 (0.0688)
1.35 (0.0532)
SEATING
PLANE
0.25 (0.0098)
0.10 (0.0040)
4
1
8 5
5.00
(0.1968)
4.80 (0.1890)
4.00 (0.1574)
3.80 (0.1497)
1.27 (0.0500)
BSC
6.20 (0.2441)
5.80 (0.2284)
0.51 (0.0201)
0.31 (0.0122)
COPLANARIT
Y
0.10
ADCMP394 Preliminary Technical Data
Rev. PrC | Page 14 of 14
ORDERING GUIDE
Model
1
Temperature
Range
Package
Description
Package
Option
ADCMP394ARZ −40°C to +125°C 8-Lead SOIC_N R-8
ADCMP394ARZ-R7 −40°C to +125°C 8-Lead SOIC_N R-8
EVAL-ADCMP396ARZ Evaluation Board
1
Z = RoHS Compliant Part.
©
2014
Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
PR12209-0-2/14(PrC)
