19-4342; Rev 0; 10/08
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
The MAX9610 high-side current-sense amplifier offers
precision accuracy specifications of V OS less than
500μV (max) and gain error less than 0.5% (max). This
device features an ultra-low 1μA quiescent supply current. The MAX9610 fits in a tiny, 1mm x 1.5mm μDFN
package or a 5-pin SC70 package, making this part
ideal for applications in notebook computers, cell
phones, cameras, PDAs, and all lithium-ion (Li+) battery-operated portable devices where accuracy, low
quiescent current, and small size are critical.
The MAX9610 features an input voltage range (common mode) from 1.6V to 5.5V. This input range is excellent for monitoring the current of a single-cell,
lithium-ion battery, which at full charge is 4.2V, typically
3.6V in normal use, and less than 2.9V when ready to
be recharged. These current-sense amplifiers have a
voltage output and are offered in three gain versions:
25V/V (MAX9610T), 50V/V (MAX9610F), and 100V/V
(MAX9610H).
The three gain versions offer flexibility in the choice of
the external current-sense resistor. The very low 500μV
(max) input offset voltage allows small 25mV to 50mV
full-scale VSENSE voltage for very low voltage drop at
full-load current measurement.
The MAX9610 is offered in tiny 6-pin μDFN, (1mm x
1.5mm x 0.8mm footprint) and 5-pin SC70 packages,
specified for operation over the -40°C to +85°C temperature range.
For a very similar 1.6V to 28V input voltage device in a
4-bump UCSP™ package (1mm x 1mm x 0.6mm), refer
to the MAX9938 data sheet.
Features
♦ Ultra-Low Supply Current of 1µA (max)
♦ Low 500µV (max) Input Offset Voltage
♦ Low < 0.5% (max) Gain Error
♦ Input Common Mode: +1.6V to +5.5V
♦ Voltage Output
♦ Three Gain Versions Available
25V/V (MAX9610T)
50V/V (MAX9610F)
100V/V (MAX9610H)
♦ Tiny µDFN (1mm x 1.5mm x 0.8mm) and
SC70 Packages
Ordering Information
PINPACKAGE
PART*
GAIN
(V/V)
TOP MARK
MAX9610TELT+T
6 μDFN
25
OU
MAX9610FELT+T
6 μDFN
50
OS
MAX9610HELT+T
6 μDFN
100
OT
MAX9610TEXK+T
5 SC70
25
ATG
MAX9610FEXK+T
5 SC70
50
ATE
MAX9610HEXK+T
5 SC70
100
ATF
*All devices are specified over the -40°C to +85°C extended
temperature range.
+Denotes a lead-free/RoHS-compliant package.
T = Tape and reel.
Typical Operating Circuit
Applications
ILOAD
RSENSE
Cell Phones
RS+
Cameras
RSLOAD
Portable Li+ Battery Powered Systems
3.3V and 5V Power Management Systems
PDAs
R1
R1
VBATT =
1.6V to 5.5V
USB Ports
VDD = 3.3V
P
μC
OUT
Pin Configurations appear at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
ROUT
10kΩ
ADC
MAX9610
GND
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
1
MAX9610
General Description
MAX9610
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
ABSOLUTE MAXIMUM RATINGS
RS+, RS- to GND......................................................-0.3V to +6V
OUT to GND .............................................................-0.3V to +6V
RS+ to RS- .............................................................................±6V
Short-Circuit Duration: OUT to GND or RS+ ..............Continuous
Continuous Input Current (Any Pin)..................................±20mA
Continuous Power Dissipation (TA = +70°C)
5-Pin SC70 (derate 3.1mW/°C above +70°C) ..............247mW
6-Pin μDFN (derate 2.1mW/°C above +70°C) .............168mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Package Reflow Soldering Temperature .........................+260°C
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
(VRS+ = VRS- = 3.6V, VSENSE = (VRS+ - VRS-) = 0, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
VRS+ = 3.6V, TA = +25°C
Supply Current
(Note 2)
ICC
TYP
MAX
0.6
1.0
VRS+ = 3.6V, -40°C < TA < +85°C
1.4
VRS+ = 5.5V, TA = +25°C
0.75
VRS+ = 5.5V, -40°C < TA < +85°C
Common-Mode Input Range
Common-Mode Rejection Ratio
VCM
CMRR
VOS
Guaranteed by CMRR,
-40°C < TA < +85°C
1.6
1.6V < VRS+ < 5.5V, -40°C < TA < +85°C
80
-40°C < TA < +85°C
Gain Error
G
GE
Output Resistance
ROUT
OUT Low Voltage
VOL
OUT High Voltage
2
VOH
5.5
104
±100
dB
±600
Gain = 100
±700
μV
25
MAX9610F
50
MAX9610H
100
TA = +25°C, gain = 25, 50, 100 (Note 4)
±0.1
-40°C < TA < +85°C
V
±500
Gain = 25, 50
MAX9610T
Gain
μA
1.6
TA = +25°C, gain = 25, 50, 100 (Note 3)
Input Offset Voltage
1.2
UNITS
Gain = 25, 50
±0.5
±0.8
Gain = 100
TA = +25°C (Note 5)
V/V
%
±1
7.0
10
13.2
G = 25
2.5
15
G = 50
5
30
G = 100
10
70
VOH = VRS- - VOUT (Note 6)
0.1
0.2
_______________________________________________________________________________________
kΩ
mV
V
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
(VRS+ = VRS- = 3.6V, VSENSE = (VRS+ - VRS-) = 0, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.)
(Note 1)
PARAMETER
SYMBOL
Small-Signal Bandwidth
CONDITIONS
BW
TYP
170
MAX
UNITS
kHz
VSENSE = 50mV, G = 50
110
VSENSE = 50mV, G = 100
60
tS
1% final value, VSENSE = 25mV
35
μs
tON
1% final value, VSENSE = 25mV
100
μs
Output Settling Time
Power-Up Time
MIN
VSENSE = 50mV, G = 25
All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design.
VOUT = 0V. ICC is the total current into RS+ plus RS-.
VOS is extrapolated from measurements for the Gain Error test.
Gain Error is calculated by applying two values of VSENSE and calculating the error of the slope, vs. the ideal:
G = 25: VSENSE 20mV and 120mV
G = 50: VSENSE 10mV and 60mV
G = 100: VSENSE 5mV and 30mV
Note 5: The device is stable for any external capacitance value.
Note 6: VOH is the voltage from VRS- to VOUT with VSENSE = 3.6V/Gain.
Note 1:
Note 2:
Note 3:
Note 4:
Typical Operating Characteristics
(VRS+ = VRS- = 3.6V, TA = +25°C.)
25
N (%)
20
N (%)
900
800
SUPPLY CURRENT (nA)
15
10
1000
MAX9610 toc02
30
MAX9610 toc01
20
SUPPLY CURRENT
vs. TEMPERATURE
MAX9610F
GAIN ACCURACY HISTOGRAM
15
10
5
MAX9610 toc03
MAX9610F
OFFSET VOLTAGE HISTOGRAM
5.5V
3.6V
700
600
500
1.6V
400
300
200
5
100
0
0
0
-250 -200-150-100 -50
0
50 100 150 200 250
OFFSET VOLTAGE (μV)
-0.2 -0.15 -0.1 -0.05
0
0.05 0.1 0.15 0.2
GAIN ACCURACY (%)
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
3
MAX9610
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(VRS+ = VRS- = 3.6V, TA = +25°C.)
SUPPLY CURRENT
vs. COMMON-MODE VOLTAGE
0.60
0.50
0.40
0.30
70
60
50
40
30
0.20
20
0.10
10
0
2.1
2.6
3.1
3.6
4.1
4.6
5.5
40
30
20
10
0
0
-40
-15
10
35
60
85
1.6
2.1
2.6
3.1
3.6
4.1
4.6
COMMON-MODE VOLTAGE (V)
TEMPERATURE (°C)
COMMON-MODE VOLTAGE (V)
GAIN ERROR vs. TEMPERATURE
GAIN ERROR
vs. COMMON-MODE VOLTAGE
VOUT vs. VSENSE
VRS+ = 5.5V
0.21%
-0.04%
GAIN ERROR (%)
0.19%
0.17%
0.15%
0.13%
6.0
5.5
5.0
4.5
-0.06%
-0.08%
VOUT (V)
0.23%
-0.02%
-0.10%
-0.12%
0.11%
-0.14%
0.09%
-0.16%
0.07%
-0.18%
10
35
60
1.6
85
VOUT vs. VSENSE
VRS+ = 1.6V
G = 100
2.1
2.6
3.1
3.6
4.1
4.6
5.1 5.5
0
0
NORMALIZED GAIN (dB)
1.4
G = 25
1.0
G = 50
G = 100
150
200
250
CMRR vs. FREQUENCY
-40
G = 100
-60
-5
G = 50
-10
100
-20
MAX9610 toc11
5
MAX9610 toc10
1.6
1.2
50
VSENSE (mV)
NORMALIZED GAIN
vs. FREQUENCY
1.8
0.6
G = 50
COMMON-MODE VOLTAGE (V)
TEMPERATURE (°C)
0.8
G = 25
MAX9610 toc12
-15
CMRR (dB)
-40
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
-0.20%
0.05%
5.1 5.5
MAX9610 toc09
0%
MAX9610 toc07
0.25%
MAX9610 toc08
1.6
MAX9610 toc06
50
OFFSET VOLTAGE (μV)
80
0.70
60
MAX9610 toc05
90
OFFSET VOLTAGE (μV)
0.80
SUPPLY CURRENT (μA)
100
MAX9610 toc04
0.90
GAIN ERROR (%)
OFFSET VOLTAGE
vs. COMMON-MODE VOLTAGE
OFFSET VOLTAGE
vs. TEMPERATURE
1.00
VOUT (V)
MAX9610
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
G = 25
-80
-15
-100
-20
-120
0.4
0.2
0
10
20
30
40
50
VSENSE (mV)
4
-140
-25
0
60
70
80
0.1
1
10
FREQUENCY (kHz)
100
1000
10
100
1k
FREQUENCY (Hz)
_______________________________________________________________________________________
10k
100k
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
SMALL-SIGNAL RESPONSE
G = 50
SMALL-SIGNAL RESPONSE
G = 25
MAX9610 toc14
MAX9610 toc13
20mV/div
VSENSE
VOUT
200mV/div
10mV/div
VSENSE
VOUT
200mV/div
10μs/div
10μs/div
SMALL-SIGNAL RESPONSE
G = 100
LARGE-SIGNAL RESPONSE
G = 25
MAX9610 toc16
MAX9610 toc15
5mV/div
VSENSE
VOUT
200mV/div
100mV/div
VSENSE
VOUT
1V/div
10μs/div
10μs/div
LARGE-SIGNAL RESPONSE
G = 50
LARGE-SIGNAL RESPONSE
G = 100
MAX9610 toc17
MAX9610 toc18
50mV/div
VSENSE
VOUT
1V/div
10μs/div
20mV/div
VSENSE
VOUT
1V/div
10μs/div
_______________________________________________________________________________________
5
MAX9610
Typical Operating Characteristics (continued)
(VRS+ = VRS- = 3.6V, TA = +25°C.)
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
MAX9610
Pin Description
PIN
NAME
FUNCTION
µDFN
SC70
1
1, 2
GND
Ground
2, 5
—
N.C.
No Connection. Not internally
connected.
3
3
OUT
Output
4
4
RS-
Load-Side Connection to
External Sense Resistor
6
5
RS+
Power-Side Connection to
External Sense Resistor
Detailed Description
The MAX9610 family of unidirectional high-side, current-sense amplifiers features a 1.6V to 5.5V input common-mode range. The input range is excellent for
monitoring the current of a single-cell lithium-ion battery
(Li+), which at full charge is 4.2V, typically 3.6V in normal use, and less than 2.9V when ready to be
recharged. The MAX9610 is ideal for many batterypowered, handheld devices because it uses only 1μA
quiescent supply current to extend battery life. The
MAX9610 monitors current through a current-sense
resistor and amplifies the voltage across that resistor.
See the Typical Operating Circuit on page 1.
The MAX9610 is a unidirectional current-sense amplifier
that has a well-established history. An op amp is used
to force the current through an internal gain resistor at
RS+ that has a value of R1, such that its voltage drop
equals the voltage drop across an external sense resistor, RSENSE. There is an internal resistor at RS- with the
same value as R1 to minimize offset voltage. The current through R1 is sourced by a pFET. Its drain current
is the same as its source current that flows through a
second gain resistor, ROUT. This produces an output
voltage, VOUT, whose magnitude is ILOAD x RSENSE x
ROUT/R1. The gain accuracy is based on the matching
of the two gain resistors R1 and ROUT (see Table 1).
Total gain = 25V/V for the MAX9610T, 50V/V for the
MAX9610F, and 100V/V for the MAX9610H.
Applications Information
OUT Swing vs. VRS+ and VSENSE
The MAX9610 is unique since the supply voltage is the
input common-mode voltage (the average voltage at
RS+ and RS-). There is no separate VCC supply voltage
input. Therefore, the OUT voltage swing is limited by
the minimum voltage at RS+.
VOUT(MAX) = VRS+(MAX) - VSENSE(MAX) - VOH
and
RSENSE =
VOUT
G × I LOAD(MAX)
VSENSE full scale should be less than VOUT/gain at the
minimum RS+ voltage. For best performance with a
3.6V supply voltage, select RSENSE to provide approximately 120mV (gain of 25V/V), 60mV (gain of 50V/V), or
30mV (gain of 100V/V) of sense voltage for the fullscale current in each application. These can be
increased by use of a higher minimum input voltage.
Accuracy
In the linear region (VOUT < VOUT(MAX)), there are two
components to accuracy: input offset voltage (VOS) and
Gain Error (GE). The MAX9610 has VOS = 500μV (max)
and Gain Error of 0.5% (max). Use the following linear
equation to calculate total error.
VOUT = (Gain ± GE) x VSENSE ± (Gain x VOS)
A high RSENSE value allows lower currents to be measured more accurately because offsets are less significant when the sense voltage is larger.
Efficiency and Power Dissipation
At high current levels, the I2R loss in RSENSE can be
significant. Take this into consideration when choosing
the resistor value and its power dissipation (wattage)
rating. Also, the sense resistor’s value might drift if it is
allowed to heat up excessively. The precision VOS of
the MAX9610 allows the use of small sense resistors to
reduce power dissipation and reduce hot spots.
Table 1. MAX9610, Internal Gain Setting
Resistors (Typical Values)
GAIN (V/V)
R1 (Ω)
ROUT (Ω)
Choose RSENSE based on the following criteria.
100
100
10k
Voltage Loss
A high RSENSE value causes the power-source voltage
to drop due to IR loss. For minimal voltage loss, use the
lowest RSENSE value.
50
200
10k
25
400
10k
Choosing the Sense Resistor
6
_______________________________________________________________________________________
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
Optional Output Filter Capacitor
When designing a system that uses a sample and hold
stage in the analog-to-digital converter, the sampling
capacitor momentarily loads OUT and causes a drop in
the output voltage. If sampling time is very short (less
than a microsecond), consider using a ceramic capacitor across OUT and GND to hold VOUT constant during
sampling. This also decreases the small-signal bandwidth of the current-sense amplifier and reduces noise
at OUT.
ILOAD
Typical Application Circuit
Bidirectional Application
Battery-powered systems may require a precise bidirectional current-sense amplifier to accurately monitor
the battery’s charge and discharge currents.
Measurements of the two separate outputs with respect
to GND yield an accurate measure of the charge and
discharge currents, respectively (Figure 1).
RSENSE
TO WALL-CUBE/
CHARGER
RS+
RS-
RS+
RSLOAD
R1
R1
R1
R1
VDD = 3.3V
VBATT = 1.6V TO 5.5V
P
P
MICROCONTROLLER
OUT
ROUT
MAX9610
GND
OUT
ROUT
MAX9610
ADC
GND
ADC
Figure 1. Bidirectional Application
_______________________________________________________________________________________
7
MAX9610
Kelvin Connections
Because of the high currents that flow through RSENSE,
take care to eliminate parasitic trace resistance from
causing errors in the sense voltage. Either use a four
terminal current-sense resistor or use Kelvin (force and
sense) PCB layout techniques.
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
MAX9610
Pin Configurations
Chip Information
PROCESS: BiCMOS
TOP VIEW
(PINS ON BOTTOM)
RS+
N.C.
RS-
6
5
4
MAX9610T/F/H
+
1
2
3
GND
N.C.
OUT
1mm x 1.5mm μDFN
TOP VIEW
RS+
5
RS4
MAX9610T/F/H
+
1
2
GND
GND
3
OUT
2mm x 2.2mm SC70
(DIAGRAMS NOT TO SCALE.)
8
_______________________________________________________________________________________
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
PACKAGE CODE
DOCUMENT NO.
6 μDFN
L611+1
21-0147
5 SC70
X5+1
21-0076
TOPMARK
3
2
5
e
A
4
b
5
4
AA
PIN 1
MARK
6L UDFN.EPS
PACKAGE TYPE
6
PIN 1
0.075x45∞
L
E
1
A2
D
A1
TOP VIEW
3
2
A
L1
SIDE VIEW
A
1
L2
BOTTOM VIEW
COMMON DIMENSIONS
b
SECTION A-A
MIN.
0.65
-0.00
1.45
0.95
0.30
0.00
0.05
0.17
A
A1
A2
D
E
L
L1
L2
b
e
Pkg.
Code
NOM.
0.72
0.20
-1.50
1.00
0.35
--0.20
0.50 BSC.
MAX.
0.80
-0.05
1.55
1.05
0.40
0.08
0.10
0.23
L611-1, L611-2
TITLE:
PACKAGE OUTLINE, 6L uDFN, 1.5x1.0x0.8mm
APPROVAL
-DRAWING NOT TO SCALE-
DOCUMENT CONTROL NO.
21-0147
REV.
E
1
2
_______________________________________________________________________________________
9
MAX9610
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
MAX9610
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
TABLE 1
Translation Table for Calendar Year Code
Calendar Year
2006
Marked with bar
Legend:
TABLE 2
2005
2007
2008
2009
2010
2011
2012
2013
42-47
48-51
52-05
2014
Blank space - no bar required
Translation Table for Payweek Binary Coding
Payweek
Legend:
06-11
12-17
Marked with bar
18-23
24-29
30-35
36-41
Blank space - no bar required
TITLE:
PACKAGE OUTLINE, 6L uDFN, 1.5x1.0x0.8mm
APPROVAL
-DRAWING NOT TO SCALE-
10
DOCUMENT CONTROL NO.
21-0147
______________________________________________________________________________________
REV.
E
2
2
1µA, µDFN/SC70, Lithium-Ion Battery,
Precision Current-Sense Amplifier
SC70, 5L.EPS
PACKAGE OUTLINE, 5L SC70
21-0076
E
1
1
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11
© 2008 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
MAX9610
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.