19-5015; Rev 3; 6/11
KIT
ATION
EVALU
BLE
AVAILA
-20V to +75V Input Range, Precision
Uni-/Bidirectional, Current-Sense Amplifiers
General Description
Features
o
-20V to +75V Input Common-Mode Voltage Range
o
400µV (max) Input Offset Voltage
o
0.6% (max) Gain Accuracy Error
o
Uni- or Bidirectional Current Sensing
o
Reference Input for Bidirectional OUT
o
120kHz, -3dB Bandwidth (MAX9919N)
o
Single-Supply Operation (4.5V to 5.5V)
o
1mA Supply Current
o
0.5µA (typ) Shutdown Current
o
Rail-to-Rail Output
o
-40°C to +125°C Automotive Temperature Range
MAX9918/MAX9919/MAX9920
The MAX9918/MAX9919/MAX9920 are single-supply,
high-accuracy current-sense amplifiers with a high
input common-mode range that extends from -20V to
+75V. These amplifiers are well suited for current moni-
toring of inductive loads such as motors and solenoids,
where common-mode voltages can become negative
due to inductive kickback, reverse-battery conditions,
or transient events.
The MAX9918/MAX9920 feature adjustable gain set by
an external resistive-divider network. The MAX9919 fea-
tures fixed gains of 45V/V (MAX9919F) and 90V/V
(MAX9919N). The MAX9918/MAX9919/MAX9920 oper-
ate as unidirectional amplifiers when V
REFIN
= GND
and as bidirectional amplifiers when V
REFIN
= V
CC
/2.
The MAX9920 attenuates the input signal by a factor of
4 at the input level-shifting stage allowing the device to
sense voltages up to 200mV (unidirectional operation)
or ±100mV (bidirectional operation).
The MAX9918/MAX9919/MAX9920 operate with a sin-
gle 5V supply voltage, are fully specified over the -40°C
to +125°C automotive temperature range, and are
available in an 8-pin SOIC package.
Ordering Information/
Selector Guide
PART
MAX9918ASA+
MAX9918ASA/V+
MAX9919FASA+
MAX9919NASA+
MAX9920ASA+
V
SENSE
(mV)
±50
±50
±50
±50
±200
GAIN
(V/V)
Adjustable
Adjustable
45
90
Adjustable
PIN-PACKAGE
8 SOIC-EP*
8 SOIC-EP*
8 SOIC-EP*
8 SOIC-EP*
8 SOIC-EP*
Applications
H-Bridge Motor Current Sensing
Solenoid Current Sensing
Current Monitoring of Inductive Loads
High- and Low-Side Precision Current Sensing
4x4 Transmission Control
Electronic Throttle Control
Super-Capacitor Charge/Discharge Monitoring in
Hybrid Cars
Precision High-Voltage Current Monitoring
Note:
All devices operate over the -40°C to +125°C temperature
range.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
*EP
= Exposed pad.
Typical Operating Circuit
V
BATT
V
CC
V
CC
φ1A
R
SENSE
M
φ2B
MAX9918
MAX9920
A
OUT
R2
ADC
RS+
INPUT STAGE
LEVEL SHIFTER
FB
R1
REFIN
ADJUSTABLE GAIN
SHDN
GND
GND
REF
μC
RS-
φ2B
φ1B
________________________________________________________________
Maxim Integrated Products
1
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.
-20V to +75V Input Range, Precision
Uni-/Bidirectional, Current-Sense Amplifiers
MAX9918/MAX9919/MAX9920
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ..............................................................-0.3V to +6V
RS+, RS- to GND (V
CC
= 5V) ..................................-30V to +80V
RS+, RS- to GND (V
CC
= 0V) .............-15V to +80V (15 minutes)
Differential Input Voltage (V
RS+
- V
RS-
)
(MAX9918/MAX9919).................................±15V (Continuous)
Differential Input Voltage
(V
RS+
- V
RS-
) (MAX9920) .............................±5V (Continuous)
REFIN, FB, OUT to GND.............................-0.3V to (V
CC
+ 0.3V)
SHDN to GND.........................................................-0.3V to +20V
**As
per JEDEC51 Standard (multilayer board).
Output Short Circuit to V
CC
or GND...........................Continuous
Continuous Current into Any Pin
(Not to exceed package power dissipation) ................±20mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SOIC-EP (derate 24.4mW/°C above +70°C) .1951.2mW**
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
PACKAGE THERMAL CHARACTERISTICS (Note 1)
SOIC-EP
Junction-to-Ambient Thermal Resistance (θ
JA
) ...........41°C/W
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
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
(V
CC
= 5V, V
RS+
= V
RS-
= +14V, V
SENSE
= (V
RS+
- V
RS-
) = 0V, V
SHDN
= V
GND
= 0V, V
REFIN
= V
CC
/2, R
L
= 100kΩ; for MAX9918, A
V
=
90V/V, R2/R1 = 89kΩ/1kΩ; for MAX9920, A
V
= 20V/V, R2/R1 = 79kΩ/1kΩ; T
A
= -40°C to +125°C, unless otherwise noted. Typical val-
ues are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
V
RS+
= V
RS-
=
+14V, V
REFIN
= 0V
MAX9918
V
RS+
= V
RS-
=
-2V, V
REFIN
=
0V
V
RS+
= V
RS-
=
+14V, V
REFIN
= 0V
Input Offset Voltage (Note 2)
V
OS
MAX9919_
V
RS+
= V
RS-
=
-2V, V
REFIN
=
0V
V
RS+
= V
RS-
=
+14V, V
REFIN
= 0V
MAX9920
V
RS+
= V
RS-
=
-2V, V
REFIN
=
0V
T
A
= +25°C
T
A
= -40°C
to +125°C
T
A
= +25°C
T
A
= -40°C
to +125°C
T
A
= +25°C
T
A
= -40°C
to +125°C
T
A
= +25°C
T
A
= -40°C
to +125°C
T
A
= +25°C
T
A
= -40°C
to +125°C
T
A
= +25°C
T
A
= -40°C
to +125°C
±0.10
±0.48
±0.11
±0.18
±0.08
MIN
TYP
±0.14
MAX
±0.4
±0.7
±0.4
±1.3
±0.4
±0.9
±0.4
±1.0
±1.2
±3.0
±0.9
±3.5
mV
UNITS
2
_______________________________________________________________________________________
-20V to +75V Input Range, Precision
Uni-/Bidirectional, Current-Sense Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V, V
RS+
= V
RS-
= +14V, V
SENSE
= (V
RS+
- V
RS-
) = 0V, V
SHDN
= V
GND
= 0V, V
REFIN
= V
CC
/2, R
L
= 100kΩ; for MAX9918, A
V
=
90V/V, R2/R1 = 89kΩ/1kΩ; for MAX9920, A
V
= 20V/V, R2/R1 = 79kΩ/1kΩ; T
A
= -40°C to +125°C, unless otherwise noted. Typical val-
ues are at T
A
= +25°C.) (Note 1)
PARAMETERS
SYMBOL
MAX9918
Input Offset Voltage Drift
(Note 3)
V
OSD
MAX9919_
MAX9920
Common-Mode Range
Common-Mode Rejection Ratio
(Note 3)
V
CM
CONDITIONS
V
RS+
= V
RS-
= +14V
V
RS+
= V
RS-
= -2V
V
RS+
= V
RS-
= +14V
V
RS+
= V
RS-
= -2V
V
RS+
= V
RS-
= +14V
V
RS+
= V
RS-
= -2V
-20
80
96
72
86
±175
±250
0
-20V
≤
V
CM
≤
+75V, V
SHDN
= V
CC
= 5V
V
RS+
= V
RS-
= +14V, +75V, V
CC
= 0V
MAX9918,
MAX9919_
Input Resistance
MAX9920
Full-Scale Sense Voltage (Note 4)
V
SENSE
Inferred from gain
error test
MAX9918, MAX9920
Gain (Notes 2, 4)
G
MAX9919F
MAX9919N
Minimum Adjustable Gain
G
ADJ
MAX9918
MAX9920
Common mode
Differential
Common mode
Differential
MAX9918, MAX9919_
MAX9920
300
715
330
224
50
200
Adj
45
90
30
7.5
V/V
V/V
±8
±30
±30
μA
μA
μA
μA
kΩ
Ω
kΩ
Ω
mV
dB
-2V
≤
V
CM
≤
+14V
-20V
≤
V
CM
≤
+75V
-2V
≤
V
CM
≤
+14V
-20V
≤
V
CM
≤
+75V
T
A
= +25°C
T
A
= -40°C to +125°C
MIN
TYP
±1.2
±3.3
±1.8
±1.8
±2.4
±8.8
+75
V
μV/°C
MAX
UNITS
MAX9918/MAX9919/MAX9920
Inferred from CMRR tests
MAX9918, MAX9919
CMRR
MAX9920
Input Bias Current
Input Offset Current
Input Leakage Current in
Shutdown
Input Leakage Current
I
RS+
, I
RS-
(I
RS+
- I
RS-
)
-20V
≤
V
CM
≤
+75V
_______________________________________________________________________________________
3
-20V to +75V Input Range, Precision
Uni-/Bidirectional, Current-Sense Amplifiers
MAX9918/MAX9919/MAX9920
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V, V
RS+
= V
RS-
= +14V, V
SENSE
= (V
RS+
- V
RS-
) = 0V, V
SHDN
= V
GND
= 0V, V
REFIN
= V
CC
/2, R
L
= 100kΩ; for MAX9918, A
V
=
90V/V, R2/R1 = 89kΩ/1kΩ; for MAX9920, A
V
= 20V/V, R2/R1 = 79kΩ/1kΩ; T
A
= -40°C to +125°C, unless otherwise noted. Typical val-
ues are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
T
A
= +25°C,
V
REFIN
= 0V
T
A
= -40°C to
+125°C,
V
REFIN
= 0V
T
A
= +25°C
T
A
= -40°C to
+125°C
±0.13
±0.02
MIN
TYP
±0.08
MAX
±0.6
UNITS
V
RS+
= V
RS-
=
+14V
MAX9918
V
RS+
= V
RS-
=
-2V, V
REFIN
=
0V
±1.2
±0.6
±1.0
±0.45
±1.2
±0.10
±0.45
±0.9
±0.16
±0.6
±1.2
±0.11
±0.6
±1.0
±0.29
±1.0
±1.7
±0.24
±1.0
±1.7
5
15
10
mV
40
10
mV
40
mA
Ω
V
CC
-
1.9
V
V
CC
-
2.4
nA
%
MAX9919F
Gain Error
(Note 2)
GE
V
RS+
= V
RS-
= T
A
= +25°C
+14V, V
REFIN
= T
A
= -40°C to
0V
+125°C
V
RS+
= V
RS-
=
-2V, V
REFIN
=
0V
T
A
= +25°C
T
A
= -40°C to
+125°C
MAX9919N
V
RS+
= V
RS-
= T
A
= +25°C
+14V, V
REFIN
= T
A
= -40°C to
0V
+125°C
V
RS+
= V
RS-
=
-2V, V
REFIN
=
0V
T
A
= +25°C
T
A
= -40°C to
+125°C
MAX9920
V
RS+
= V
RS-
= T
A
= +25°C
+14V, V
REFIN
= T
A
= -40°C to
0V
+125°C
V
RS+
= V
RS-
=
-2V, V
REFIN
=
0V
T
A
= +25°C
T
A
= -40°C to
+125°C
FB Input Bias Current
Output-Voltage High (Note 4)
I
FB
MAX9918, MAX9920
R
L
= 100kΩ to GND
R
L
= 10kΩ to GND
R
L
= 100kΩ to V
CC
R
L
= 10kΩ to V
CC
Output-Voltage Low (Note 4)
Short-Circuit Current
Output Resistance
V
SENSE
= 200mV for
MAX9918, MAX9919_,
V
CC
- V
OH
V
SENSE
= 400mV for
MAX9920
V
SENSE
= -200mV for
MAX9918, MAX9919_,
V
OL
V
SENSE
= -400mV for
MAX9920
OUT shorted to V
CC
I
SC
OUT shorted to GND
R
OUT
3
12
3
10
44
41
0.1
V
CC
/2
V
CC
/2
MAX9918, MAX9919_
REFIN Voltage Range
Inferred from REFIN
CMRR test
MAX9920
0
0
4
_______________________________________________________________________________________
-20V to +75V Input Range, Precision
Uni-/Bidirectional, Current-Sense Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V, V
RS+
= V
RS-
= +14V, V
SENSE
= (V
RS+
- V
RS-
) = 0V, V
SHDN
= V
GND
= 0V, V
REFIN
= V
CC
/2, R
L
= 100kΩ; for MAX9918, A
V
=
90V/V, R2/R1 = 89kΩ/1kΩ; for MAX9920, A
V
= 20V/V, R2/R1 = 79kΩ/1kΩ; T
A
= -40°C to +125°C, unless otherwise noted. Typical val-
ues are at T
A
= +25°C.) (Note 1)
PARAMETERS
REFIN Common-Mode Rejection
Ratio
SYMBOL
CONDITIONS
MAX9918, MAX9919_
REFIN
CMRR
MAX9920
REFIN Current
SHDN Logic-High
SHDN Logic-Low
SHDN Logic Input Current
Supply Voltage Range
Power-Supply Rejection Ratio
(Note 3)
V
CC
PSRR
I
REFIN
V
IH
V
IL
0
≤
V
SHDN
≤
V
CC
Inferred from PSRR test
MAX9918, MAX9919_
MAX9920
V
RS+
= V
RS-
= +14V
Supply Current
I
CC
V
RS+
= V
RS-
= -2V
Shutdown Supply Current
I
CC_SHDN
V
SHDN
= V
CC
= 5V
MAX9918, V
SENSE
= 50mV
Small Signal -3dB Bandwidth
BW
MAX9919F, V
SENSE
= 50mV
MAX9919N, V
SENSE
= 50mV
MAX9920, V
SENSE
= 200mV
MAX9918
Slew Rate
SR
MAX9919F
MAX9919N
MAX9920
MAX9918
MAX9919F
1% Settling Time from V
SENSE
Step
MAX9919N
MAX9920
V
SENSE
= 5mV to 50mV step
V
SENSE
= 50mV to 5mV step
V
SENSE
= 5mV to 50mV step
V
SENSE
= 50mV to 5mV step
V
SENSE
= 5mV to 50mV step
V
SENSE
= 50mV to 5mV step
V
SENSE
= 20mV to 200mV step
V
SENSE
= 200mV to 20mV step
4.5V
≤
V
CC
≤
5.5V
4.5V
≤
V
CC
≤
5.5V
T
A
= +25°C
T
A
= -40°C to +125°C
T
A
= +25°C
T
A
= -40°C to +125°C
0.5
75
250
120
230
0.6
0.9
3.0
1.5
12
7
3.5
2.5
3.5
3
5
3
μs
V/μs
kHz
1.0
4.5
74
68
103
100
0.7
1.2
1.5
1.6
2.2
10
μA
mA
0V
≤
V
REFIN
≤
(V
CC
- 1.9V)
0V
≤
V
REFIN
≤
(V
CC
- 2.4V)
MIN
82
75
TYP
103
dB
90
±100
±100
2.0
0.8
5
5.5
μA
V
V
μA
V
dB
MAX
UNITS
MAX9918/MAX9919/MAX9920
MAX9918, MAX9919_, V
RS+
= V
RS-
= ±50mV
MAX9920, V
RS+
= V
RS-
= ±200mV
_______________________________________________________________________________________
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