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MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
General Description
The MAX9644/MAX9645/MAX9646 are small, single
comparators, ideal for a wide variety of portable electronics
applications such as cell phones, media players, and
notebooks that have extremely tight board space and
power constraints. These comparators are offered in
both a miniature 4-bump UCSP™ package with a 1mm
x 1mm footprint (as small as two 0402 resistors) and a
5-pin SOT23 package.
The ICs feature an input voltage range of -0.3V to +5.5V,
independent of supply voltage. These devices maintain
high impedance at the inputs even when powered down
(VCC or VREF = 0V). They also feature internal filtering to
provide high RF immunity.
The ICs have an internal 0.2V reference. These devices
feature either a push-pull or an open-drain output. They
consume only 700nA (max) supply current and operate
down to VCC = 1V over the extended -40ºC to +85ºC
temperature range.
Applications
●●
●●
●●
●●
●●
Cell Phones
Portable Media Players
Electronic Toys
Notebook Computers
Portable Medical Devices
Benefits and Features
●● Tiny, 1mm x 1mm x 0.6mm 4-Bump UCSP
• Footprint = Two 0402 Resistors
• Also Available in a 5-Pin SOT23 Package
●● Ultra-Low Operating Current (700nA max)
●● -0.3V to +5.5V Input Voltage Range
●● Internal 0.2V Reference Trimmed to 1% Accuracy
●● 15μs Propagation Delay
●● -40ºC to +85ºC Extended Temperature Range
Ordering Information
PIN-PACKAGE
TOP MARK
MAX9644EBS+G45
PART
4 UCSP
+AGL
MAX9644EUK+
5 SOT23
+AFJN
MAX9645EBS+G45
4 UCSP
+AGM
MAX9645EUK+
5 SOT23
+AFJO
MAX9646EBS+G45
4 UCSP
+AGN
MAX9646EUK+
5 SOT23
+AFJP
Note: All devices are specified over the extended -40°C to
+85°C operating temperature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
G45 = Protective die coating.
Selector Guide
PART
REFERENCE VOLTAGE (V)
INPUT
OUTPUT
MAX9644
0.2
Noninverting
Open-Drain
MAX9645
0.2
Inverting
Open-Drain
MAX9646
0.2
Noninverting
Push-Pull
UCSP is a trademark of Maxim Integrated Products, Inc.
19-5803; Rev 3; 11/19
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Absolute Maximum Ratings
VCC, REF, IN to GND...............................................-0.3V to +6V
OUT to GND (MAX9644/MAX9645).........................-0.3V to +6V
OUT to GND (MAX9646 only)................ -0.3V to + (VCC + 0.3V)
Output Short-Circuit Current Duration.................................... 10s
Input Current into Any Terminal.........................................±20mA
Continuous Power Dissipation
4-Bump UCSP (derate 3.0mW/ºC above +70ºC).........238mW
5-Pin SOT23 (derate 3.9mW/ºC above +70ºC)............312mW
Operating Temperature Range.............................-40ºC to +85ºC
Junction Temperature....................................................... +150ºC
Storage Temperature Range..............................-65°C to +150ºC
Bump Temperature (soldering) Reflow............................. +235ºC
Lead Temperature (soldering, 10s).................................. +300ºC
Soldering Temperature (reflow)........................................ +260ºC
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 = 3.3V, RPULLUP = 10kΩ to VPULLUP = 3.3V for MAX9644/MAX9645, TA = -40°C to +85°C. Typical values at TA = +25°C, unless
otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
+5.5
V
DC CHARACTERISTICS
Input Voltage Range
Input Bias Current
Input Leakage Current
Output Voltage Low
Output Voltage High
(MAX9464 Only)
Output Leakage Current
(MAX9644/MAX9645 Only)
VIN
Guaranteed by IIN test
IIN
VIN = 0.2V to 5.5V (Note 2)
0.06
15
nA
VCC = 0V, VIN = 5.5V (Note 2)
< 0.1
15
nA
ISINK = 50µA, VCC = 1.0V
0.03
0.2
ISINK = 200µA, VCC = 1.2V
0.08
0.20
ISINK = 500µA, VCC = 1.8V
0.13
0.23
ISINK = 0.75mA, VCC = 3.3V
0.14
0.3
ISINK = 1.2mA, VCC = 5.5V
0.19
0.5
ISOURCE = 15µA, VCC = 1.0V
VCC 0.08V
VCC - 0.2V
ISOURCE = 40µA, VCC = 1.2V
VCC 0.08V
VCC 0.20V
ISOURCE = 180µA, VCC = 1.8V
VCC 0.15V
VCC 0.23V
ISOURCE = 0.3mA, VCC = 3.3V
VCC 0.13V
VCC - 0.3V
ISOURCE = 0.75mA, VCC = 5.5V
VCC 0.24V
VCC - 0.5V
OUT = high, VPULLUP = 5.5V
(Note 2)
< 0.1
15
IIN_SHDN
VOL
VOH
IOUT_LEAKAGE
-0.3
V
V
nA
AC CHARACTERISTICS
Propagation Delay
tPD
VOVERDRIVE = ±100mV (Note 3)
15
µs
Fall Time
tF
CL = 10pF
14
ns
Rise Time
tR
CL = 10pF, MAX9646 only
30
ns
REFERENCE VOLTAGE
Input Threshold (Note 4)
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VREF
MAX964_EBS+
200
MAX964_EUK+
199
mV
Maxim Integrated │ 2
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Electrical Characteristics (continued)
(VCC = 3.3V, RPULLUP = 10kΩ to VPULLUP = 3.3V for MAX9644/MAX9645, TA = -40°C to +85°C. Typical values at TA = +25°C, unless
otherwise noted.) (Note 1)
PARAMETER
SYMBOL
Input Threshold Error
(Note 4)
Delta-VREF
Input Threshold Hysteresis
VHYS
REF Tempco
CONDITIONS
MIN
TA = +25°C
TA = -40°C to +85°C
TYP
+1
-3.5
+3.5
TA = -40°C to +85°C (Note 5)
VREF_TEMPCO (Note 6)
Power-Supply Rejection
Ratio
PSRR
VCC = 1.0V to 5.5V
MAX
-1
40
UNITS
%
±0.9
mV
6
µV/°C
53
dB
POWER SUPPLY
Supply Voltage
VCC
Supply Current
ICC
Power-Up Time
tON
Note
Note
Note
Note
Note
Note
Guaranteed by VOL/VOH tests
1.0
5.5
VCC = 1.0V
0.4
0.7
VCC = 5.5V
0.6
1.1
V
µA
3
ms
1: All devices are 100% production tested at TA = +25°C. Temperature limits are guaranteed by design.
2: Too small to be measured in an ATE test environment. Only gross test to catch failures is implemented.
3: Overdrive is defined as the voltage above or below the switching points.
4: Guaranteed by ATE and/or bench characterization over temperature. VREF is the average of the trip points.
5: Hysteresis is half the input voltage difference between the two switching points.
6: Includes reference error along with comparator offset voltage error.
Typical Operating Characteristics
(VCC = 3.3V, VREF = 1.8V, RPULLUP = 10kΩ to VPULLUP = 3.3V for MAX9644/MAX9645, VGND = 0V, TA = +25°C, unless otherwise
noted.)
SUPPLY CURRENT
vs. OUTPUT TRANSITION FREQUENCY
+25C
600
400
10
VCC = 3.3V
VCC = 1.8V
200
MAX9644 toc03
VCC = 5V
1.0
0.9
OUTPUT VOLTAGE LOW (V)
+85C
SUPPLY CURRENT (A)
SUPPLY CURRENT (nA)
800
100
MAX9644 toc01
1000
OUTPUT VOLTAGE LOW
vs. SINK CURRENT
MAX9644 toc02
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
0.8
0.7
0.6
0.5
VREF = 5V
0.4
0.3
VREF = 3.3V
0.2
-40C
0
1
2
VREF = 1.8V
0.1
1
0
3
4
SUPPLY VOLTAGE (V)
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5
6
0
0.1
1
10
OUTPUT TRANSITION FREQUENCY (kHz)
100
0
2
4
6
8
SINK CURRENT (mA)
Maxim Integrated │ 3
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Typical Operating Characteristics (continued)
(VCC = 3.3V, VREF = 1.8V, RPULLUP = 10kΩ to VPULLUP = 3.3V for MAX9644/MAX9645, VGND = 0V, TA = +25°C, unless otherwise
noted.)
OUTPUT VOLTAGE HIGH
vs. SOURCE CURRENT (MAX9646)
0.9
INPUT BIAS CURRENT (nA)
0.8
0.7
0.6
0.5
VCC = 5V
0.4
0.3
VCC = 3.3V
0.2
-5
-10
-15
VCC = 3.3V
-20
0.5
1.0
1.5
2.0
2.5
3.0
0
0.05
0.10
0.15
0.20
0.25
SOURCE CURRENT (mA)
INPUT BIAS VOLTAGE (V)
REFERENCE VOLTAGE
vs. TEMPERATURE
REFERENCE VOLTAGE
vs. SUPPLY VOLTAGE
VCC = 3.3V
201.9
201.0
200.8
REFERENCE VOLTAGE (mV)
201.8
201.7
201.6
201.5
201.4
201.3
200.6
200.4
200.2
200.0
199.8
199.6
201.2
199.4
201.1
199.2
201.0
0.30
MAX9644 toc07
202.0
MAX9644 toc06
0
199.0
-15
10
35
60
85
1.0
1.5
2.0
2.5
3.0
3.5
4.0
TEMPERATURE (C)
SUPPLY VOLTAGE (V)
PROPAGATION DELAY
vs. TEMPERATURE
PROPAGATION DELAY
vs. INPUT OVERDRIVE
VOD = 100mV
16
15
VCC = 5V
14
13
VCC = 3.3V
12
VCC = 1.8V
11
10
4.5
80
70
PROPAGATION DELAY (s)
17
MAX9644 toc08
-40
5.0
MAX9644 toc09
REFERENCE VOLTAGE (mV)
0
VCC = 1.8V
0.1
0
PROPAGATION DELAY (s)
MAX9644 toc05
5
MAX9644 toc04
OIUTPUT VOLTAGE HIGH (VCC - VOH, V)
1.0
INPUT BIAS CURRENT
vs. INPUT BIAS VOLTAGE
60
50
VCC = 1.8V
40
VCC = 3.3V
30
VCC = 5V
20
10
9
0
-40
-15
10
35
TEMPERATURE (C)
www.maximintegrated.com
60
85
0
50
100
150
200
250
INPUT OVERDRIVE (mV)
Maxim Integrated │ 4
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Typical Operating Characteristics (continued)
(VCC = 3.3V, VREF = 1.8V, RPULLUP = 10kΩ to VPULLUP = 3.3V for MAX9644/MAX9645, VGND = 0V, TA = +25°C, unless otherwise
noted.)
MAX9644 toc10
202.0
VCC = 3.3V
201.9
REFERENCE VOLTAGE (mV)
0.3V
IN+
100mV/div
0.1V
OUT
2V/div
0V
MAX9644 toc11
REFERENCE VOLTAGE
vs. TEMPERATURE
PROPAGATION DELAY AT VCC = 3.3V
201.8
201.7
201.6
201.5
201.4
201.3
201.2
201.1
201.0
-40
100s/div
-15
10
35
60
85
TEMPERATURE (C)
OUTPUT RESPONSE TO
SUPPLY VOLTAGE TRANSIENT
POWER-UP/POWER-DOWN RESPONSE
MAX9644 toc12
MAX9644 toc13
VIN = 0.3V
VCC = 3.3V
3.2V
3V
VCC
2V/div
VIN = VTH + 1mV
VCC
200mV/div
OUT
2V/div
0V
OUT
2V/div
0V
VIN = VTH + 10mV
0V
VIN = VTH + 20mV
0V
OUT
2V/div
OUT
2V/div
0V
1ms/div
1ms/div
POWER-SUPPLY REJECTION
FOR NO FALSE TRIGGERING
MAX9644 toc14
206
TRIP POINT (mV)
204
202
UPPER TRIP POINT
200
198
LOWER TRIP POINT
196
VCC = 3.3V + 100mVP-P
194
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
www.maximintegrated.com
Maxim Integrated │ 5
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Pin Configuration
TOP VIEW (BUMPS ON BOTTOM)
OUT
A1
A2
IN
MAX9644
MAX9645
MAX9646
VCC
B1
B2
GND
VCC
1
GND
2
GND
3
+
5
OUT
4
IN
MAX9644
MAX9645
MAX9646
UCSP
SOT23
Pin Description
PIN
NAME
UCSP
SOT23
A1
5
OUT
A2
4
IN
FUNCTION
Comparator Output. The MAX9644/MAX9645 have open-drain outputs. The MAX9646 has a
push-pull output.
Comparator Input. The MAX9644/MAX9646 have noninverting inputs. The MAX9645 has
inverting inputs.
B1
1
VCC
Power-Supply Voltage. Bypass to ground with a 0.1µF bypass capacitor.
B2
2, 3
GND
Ground
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Maxim Integrated │ 6
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Detailed Description
Output Stage Structure
The MAX9644/MAX9645/MAX9646 are extremely small
comparators ideal for compact, low-current, and lowvoltage applications.
The ICs consume only 400nA (typ). The low-voltage
operating capability of the operating current makes these
devices extremely attractive to long-life battery-operated
devices—these applications can now use a single digital
power-supply rail to power the new generation of microcontrollers (which can be down to 0.9V). All parts are
available in a tiny 4-bump UCSP, which is only 0.6mm tall
and occupies a 1mm x 1mm footprint and a 5-pin SOT23.
Input Stage Circuitry
Noninverting inputs are available on the MAX9644/
MAX9646 and inverting inputs are available on the
MAX9645.
The MAX9644/MAX9645/MAX9646 incorporate an innovative input stage architecture that allows their input
voltage to exceed VCC by several volts (limited only by
the Absolute Maximum Ratings). This is unlike traditional
comparators that have an input ESD diode clamp between
the input and VCC, limiting this maximum overvoltage to
about 0.3V. The ICs architecture maintains a high input
impedance to input signals even when the device powersupply voltage is completely turned off (VCC or REF
taken to 0V). This greatly benefits flexible power-saving
schemes to be easily implemented in advanced batteryoperated devices. On-chip filtering provides immunity
from any RF noise being picked up by input traces. These
devices feature an internal temperature-compensated,
low-power 0.2V reference voltage
The MAX9644/MAX9645 have open-drain outputs that
allow them to interface to logic circuitry running from supply voltages other than the one supplied to the part. These
devices require an external pullup resistor or current
source for proper operation. Many microcontroller digital
inputs ports can be readily programmed to include these.
The MAX9646 has a push-pull output stage that can
both sink and source current, eliminating the need for an
external pullup resistor. In this case, the MAX9646 uses
the microcontroller's power supply as VCC
Applications Information
Bypassing REF/VCC
Place a 0.1μF capacitor between REF or VCC and GND
as close as possible to the device. During a switching
event, all comparators draw a current spike from their
power-supply rails. This current spike is minimized by the
use of an internal break-before-make design.
Hysteresis Operation
The ICs feature internal hysteresis for noise immunity and
glitch-free operation. If additional hysteresis is needed, an
external positive feedback network can be easily implemented on the MAX9644 and MAX9646 noninverting input
devices. Additional external hysteresis is not possible on
the MAX9645 because the noninverting input of the comparator is not externally accessible.
Table 1. How Devices Behave Under Various Input Voltage Conditions
PART
INPUT VOLTAGE CONDITIONS
MAX9644
MAX9645
MAX9646
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ACTION AT OUTPUT
VIN > 0.2V
External pullup resistor pulls output high.
VIN < 0.2V
Output asserts low.
VIN > 0.2V
Output asserts low.
VIN < 0.2V
External pullup resistor pulls output high.
VIN > 0.2V
Output asserts high.
VIN < 0.2V
Output asserts low.
Maxim Integrated │ 7
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Typical Operating Circuits
VCC = 1.0V TO 5.5V
0.2V REF
VDD
VCC = 1.0V TO 5.5V
INTERNAL
PULLUP
MAX9644
INTERNAL
PULLUP
MAX9645
0.2V REF
OUT I/O
IN
VDD
OUT I/O
MICROCONTROLLER
IN
MICROCONTROLLER
VCC = 1.0V TO 5.5V
VDD
0.2V REF
MAX9646
OUT I/O
IN
MICROCONTROLLER
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
LAND PATTERN NO.
4 UCSP
B4+1
21-0789
Refer to Application Note 1891
5 SOT23
U5+2
21-0057
90-0174
www.maximintegrated.com
Maxim Integrated │ 8
MAX9644/MAX9645/
MAX9646
nanoPower Comparators with
Precision Reference in 4-Bump UCSP
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
0
3/14
Initial release
—
1
10/11
Updated Features section
1
2
3/17
Updated title to include “nanoPower”
1–11
3
11/19
Updated Absolute Maximum Ratings and Package Information
2, 8
DESCRIPTION
For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2019 Maxim Integrated Products, Inc. │ 9
