LT6106
36V Low Cost High Side
Current Sense in a SOT-23
FEATURES
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DESCRIPTION
The
LT
®
6106
is a versatile high side current sense ampli-
fier. Design flexibility is provided by the excellent device
characteristics: 250µV maximum offset and 40nA maxi-
mum input bias current. Gain for each device is set by two
resistors and allows for accuracy better than 1%.
The LT6106 monitors current via the voltage across an
external sense resistor (shunt resistor). Internal circuitry
converts input voltage to output current, allowing for a
small sense signal on a high common mode voltage to
be translated into a ground referenced signal. The low DC
offset allows for monitoring very small sense voltages. As
a result, a small valued shunt resistor can be used, which
minimizes the power loss in the shunt.
The wide 2.7V to 44V input voltage range, high accuracy
and wide operating temperature range make the LT6106
ideal for automotive, industrial and power management
applications. The very low power supply current of the
LT6106 also makes it suitable for low power and battery
operated applications.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners.
Gain Configurable with Two Resistors
Low Offset Voltage: 250µV Maximum
Output Current: 1mA Maximum
Supply Range: 2.7V to 36V, 44V Absolute Maximum
Low Input Bias Current: 40nA Maximum
PSRR: 106dB Minimum
Low Supply Current: 65µA Typical, V
+
= 12V
Operating Temperature Range: –40°C to 125°C
Low Profile (1mm) ThinSOT™ Package
APPLICATIONS
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Current Shunt Measurement
Battery Monitoring
Power Management
Motor Control
Lamp Monitoring
Overcurrent and Fault Detection
TYPICAL APPLICATION
3V to 36V, 5A Current Sense with A
V
= 10
3V TO 36V
Measurement Accuracy vs Load Current
0.6
0.4
ACCURACY (% OF FULL SCALE)
LIMIT OVER TEMPERATURE
0.02
100
+IN
LOAD
–IN
0.2
0
–0.2
–0.4
–0.6
–0.8
LIMIT OVER TEMPERATURE
TYPICAL PART AT T
A
= 25°C
V
–
LT6106
–
V
+
OUT
1k
6106 TA01a
+
V
OUT
200mV/A
5A FULL SCALE R
IN
= 100
R
OUT
= 1k
–1.0 R
SENSE
= 0.02
A
V
= 10
V
+
= 3V
–1.2
0
1
3
2
LOAD CURRENT (A)
4
5
6106 TA01b
6106fb
For more information
www.linear.com/LT6106
1
LT6106
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
+
to V
–
)..........................................44V
Input Voltage (+IN to V
–
) ............................................. V
+
(–IN to V
–
) ............................................ V
+
Input Current........................................................–10mA
Output Short-Circuit Duration .......................... Indefinite
Operating Temperature Range (Note 4)
LT6106C/LT6106I.................................–40°C to 85°C
LT6106H ............................................ –40°C to 125°C
Specified Temperature Range (Note 4)
LT6106C .................................................. 0°C to 70°C
LT6106I................................................–40°C to 85°C
LT6106H ............................................ –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
(Note 1)
PIN CONFIGURATION
TOP VIEW
OUT 1
V
–
2
–IN 3
4 +IN
5 V
+
S5 PACKAGE
5-LEAD PLASTIC TSOT-23
T
JMAX
= 150°C,
θ
JA
= 250°C/W
ORDER INFORMATION
TAPE AND REEL (MINI)
TAPE AND REEL
(http://www.linear.com/product/LT6106#orderinfo)
PART MARKING*
PACKAGE DESCRIPTION
SPECIFIED TEMPERATURE RANGE
LT6106CS5#TRMPBF
LT6106CS5#TRPBF
LTCWK
5-Lead Plastic TSOT-23
0°C to 70°C
LT6106IS5#TRMPBF
LT6106IS5#TRPBF
LTCWK
5-Lead Plastic TSOT-23
–40°C to 85°C
LT6106HS5#TRMPBF
LT6106HS5#TRPBF
LTCWK
5-Lead Plastic TSOT-23
–40°C to 125°C
*Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Parts ending with PBF are RoHS and WEEE compliant.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
ELECTRICAL CHARACTERISTICS
SYMBOL
V
+
V
OS
ΔV
OS
/ΔT
I
B
I
OS
I
OUT
PSRR
V
SENSE(MAX)
A
V
Error
PARAMETER
Supply Voltage Range
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current (+IN)
Input Offset Current
Maximum Output Current
Power Supply Rejection Ratio
Input Sense Voltage Full Scale
Gain Error (Note 3)
CONDITIONS
The
l
denotes the specifications which apply over the full specified
operating temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 12V, V
+
= V
SENSE+
, R
IN
= 100Ω, R
OUT
= 10k, Gain = 100
unless otherwise noted. (Note 6)
MIN
l
TYP
150
MAX
36
250
350
40
65
UNITS
V
µV
µV
µV/°C
nA
nA
nA
mA
dB
V
2.7
V
SENSE
= 5mV
l
V
SENSE
= 5mV
V
+
= 12V, 36V
l
l
1
V
+
= 12V, 36V
(Note 2)
V
+
= 2.7V to 36V, V
SENSE
= 5mV
R
IN
= 500Ω (Notes 2, 7)
V
SENSE
= 500mV, R
IN
= 500Ω, R
OUT
= 10k, V
+
= 12.5V
V
SENSE
= 500mV, R
IN
= 500Ω, R
OUT
= 10k, V
+
= 36V
l
l
l
l
l
1
1
106
0.5
–0.65
–0.45
–0.25
–0.14
0
0.1
%
%
6106fb
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For more information
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LT6106
ELECTRICAL CHARACTERISTICS
SYMBOL
V
OUT(HIGH)
PARAMETER
Output Swing High
(Referred to V
+
)
Minimum Output Voltage
(Note 5)
CONDITIONS
V
SENSE
= 120mV
l
The
l
denotes the specifications which apply over the full specified
operating temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 12V, V
+
= V
SENSE+
, R
IN
= 100Ω, R
OUT
= 10k, Gain = 100
unless otherwise noted.
MIN
TYP
MAX
1.2
1.4
12
l
UNITS
V
V
mV
mV
mV
mV
kHz
µs
V
SENSE
= 0mV, R
IN
= 100Ω, R
OUT
= 10k
V
SENSE
= 0mV, R
IN
= 500Ω, R
OUT
= 10k, V
+
= 12V, 36V
l
45
65
16
22
7
200
3.5
60
l
BW
t
r
I
S
Signal Bandwidth (–3dB)
Input Step Response (to 50% of
Output Step)
Supply Current
I
OUT
= 1mA, R
IN
= 100Ω, R
OUT
= 5k
ΔV
SENSE
= 100mV Step, R
IN
= 100Ω, R
OUT
= 5k,
Rising Edge
V
+
= 2.7V, I
OUT
= 0µA, (V
SENSE
= –5mV)
V
+
= 12V, I
OUT
= 0µA, (V
SENSE
= –5mV)
l
85
115
95
120
100
130
µA
µA
µA
65
70
l
V
+
= 36V, I
OUT
= 0µA, (V
SENSE
= –5mV)
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime. In addition to the Absolute Maximum Ratings, the
output current of the LT6106 must be limited to insure that the power
dissipation in the LT6106 does not allow the die temperature to exceed
150°C. See the applications information section “Power Dissipation
Considerations” for further information.
Note 2:
Guaranteed by the gain error test.
Note 3:
Gain error refers to the contribution of the LT6106 internal
circuitry and does not include errors in the external gain setting resistors.
Note 4:
The LT6106C is guaranteed functional over the operating
temperature range of –40°C to 85°C. The LT6106C is designed,
characterized and expected to meet specified performance from –40°C to
85°C but is not tested or QA sampled at these temperatures. The LT6106I
is guaranteed to meet specified performance from –40°C to 85°C. The
LT6106H is guaranteed to meet specified performance from –40°C to
125°C.
Note 5:
The LT6106 output is an open collector current source. The
minimum output voltage scales directly with the ratio R
OUT
/10k.
Note 6:
V
SENSE+
is the voltage at the high side of the sense resistor,
R
SENSE
. See Figure 1.
Note 7:
V
SENSE (MAX)
is the maximum sense voltage for which the Electrical
Characteristics will apply. Higher voltages can affect performance but will
not damage the part provided that the output current of the LT6106 does
not exceed the allowable power dissipation as described in Note 1.
TYPICAL PERFORMANCE CHARACTERISTICS
V
OS
Distribution
14
PERCENT OF UNITS (%)
12
10
8
6
4
2
0
–200
–120
120
–40 0 40
INPUT OFFSET VOLTAGE (µV)
200
6106 G23
Input Offset Voltage vs
Supply Voltage
70
60
50
40
30
20
10
0
–10
–20
–30
–40
–50
–60
–70
CHANGE IN INPUT OFFSET VOLTAGE (µV)
V
SENSE
= 5mV
R
IN
= 100
R
OUT
= 10k
TYPICAL UNITS
400
Input Offset Voltage vs
Temperature
V
SENSE
= 5mV R
OUT
= 10k
A
V
= 100
V
+
= 12V
300
TYPICAL UNITS
R
IN
= 100
200
100
0
–100
–200
–300
16
INPUT OFFSET VOLTAGE (µV)
40
V
+
= 12V
V
SENSE
= 5mV
R
IN
= 100
R
OUT
= 10k
1068 UNITS
0
5
10 15 20 25 30
SUPPLY VOLTAGE (V)
35
–400
–55
–25
35
65
5
95
TEMPERATURE (°C)
125
6106 G03
6106 G02
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For more information
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3
LT6106
TYPICAL PERFORMANCE CHARACTERISTICS
Gain Error vs Temperature
0
–0.10
–0.15
GAIN ERROR (%)
–0.20
–0.25
–0.30
–0.35
–0.40
–0.45
–0.50
–0.55
V
OUT
= 1V
I
OUT
= 1mA
R
OUT
= 1k
TYPICAL UNIT
15 35 55 75 95 115 130
TEMPERATURE (°C)
6106 G04
Power Supply Rejection Ratio
vs Frequency
120
POWER SUPPLY REJECTION RATIO (dB)
POWER SUPPLY REJECTION RATIO (dB)
110
100
90
80
70
60
50
40
30
20
10
0
100
V
OUT
= 0.5V
V
OUT
= 1V
V
OUT
= 2V
1k
10k
100k
FREQUENCY (Hz)
1M
6106 G08
–0.05
V
+
= 36V
V
+
= 12V
V
+
= 5V
V
+
= 2.7V
V
+
= 12.5V
A
V
= 20
R
IN
= 100
R
OUT
= 2k
120
110
100
90
80
70
60
50
40
30
20
10
Power Supply Rejection Ratio
vs Frequency
V
+
= 12.5V
A
V
= 20
R
IN
= 500
R
OUT
= 10k
–0.60
–45 –25 –5
0
100
V
OUT
= 2.5V
V
OUT
= 5V
V
OUT
= 10V
1k
10k
100k
FREQUENCY (Hz)
1M
6106 G06
Gain Error Distribution
24
22
20
PERCENT OF UNITS (%)
18
16
14
12
10
8
6
4
2
0
–0.60
–0.48
–0.36 –0.24
GAIN ERROR (%)
–0.12
0
6106 G24
Gain vs Frequency
45
40
35
30
25
20
15
10
5
0
–5
–10
–15
–20
–25
–30
V
OUT
= 10V
V
OUT
= 2.5V
V
+
= 12.5V
A
V
= 100
R
IN
= 100
R
OUT
= 10k
GAIN (dB)
45
40
35
30
25
20
15
10
5
0
–5
–10
–15
–20
–25
–30
Gain vs Frequency
V
OUT
= 10V
V
OUT
= 2.5V
V
+
= 12.5V
A
V
= 20
R
IN
= 500
R
OUT
= 10k
GAIN (dB)
V
+
= 12.5V
V
SENSE
= 500mV
R
IN
= 500
R
OUT
= 10k
11,072 UNITS
T
A
= 25°C
1k
10k
100k
1M
FREQUENCY (Hz)
10M
6106 G09
1k
10k
100k
1M
FREQUENCY (Hz)
10M
6106 G14
Input Bias Current vs Supply
Voltage
20
V
SENSE
= 5mV
19 R
IN
= 100
INPUT BIAS CURRENT (nA)
18
17
16
15
14
13
12
11
10
0
5
T
A
= –40°C
T
A
= 25°C
T
A
= 70°C
T
A
= 85°C
T
A
= 125°C
10 15 20 25 30 35 40 45 50
SUPPLY VOLTAGE (V)
6106 G05
Step Response 0mV to 10mV
(R
IN
= 100Ω)
V
SENSE
20mV/DIV
V
SENSE
20mV/DIV
Step Response 10mV to 20mV
(R
IN
= 100Ω)
V
OUT
500mV/DIV
V
OUT
500mV/DIV
0V
A
V
= 100
V
OUT
= 0V TO 1V
R
OUT
= 10k
V
+
= 12V
5µs/DIV
6106 G10
0V
A
V
= 100
V
OUT
= 1V TO 2V
R
OUT
= 10k
V
+
= 12V
5µs/DIV
6106 G11
6106fb
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For more information
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LT6106
TYPICAL PERFORMANCE CHARACTERISTICS
Step Response 0mV to 100mV
(R
IN
= 100Ω)
V
SENSE
200mV/DIV
V
SENSE
200mV/DIV
Step Response 10mV to 100mV
(R
IN
= 100Ω)
V
SENSE
100mV/DIV
Step Response 50mV to 100mV
(R
IN
= 500Ω)
V
OUT
2V/DIV
V
OUT
2V/DIV
V
OUT
500mV/DIV
0V
A
V
= 100
5μs/DIV
V
OUT
= 0V TO 10V
R
OUT
= 10k
V
+
= 12V
6106 G12
0V
A
V
= 100
5µs/DIV
V
OUT
= 1V TO 10V
R
OUT
= 10k
V
+
= 12V
6106 G13
0V
A
V
= 20
V
OUT
= 1V TO 2V
R
OUT
= 10k
V
+
= 12V
5µs/DIV
6106 G15
Step Response 0mV to 50mV
(R
IN
= 500Ω)
V
SENSE
100mV/DIV
V
SENSE
1V/DIV
Step Response 50mV to 500mV
(R
IN
= 500Ω)
V
SENSE
1V/DIV
Step Response 0mV to 500mV
(R
IN
= 500Ω)
V
OUT
2V/DIV
V
OUT
500mV/DIV
0V
A
V
= 20
V
OUT
= 0V TO 1V
R
OUT
= 10k
V
+
= 12V
5µs/DIV
6106 G16
V
OUT
2V/DIV
0V
A
V
= 20
5µs/DIV
V
OUT
= 1V TO 10V
R
OUT
= 10k
V
+
= 12V
6106 G17
0V
5µs/DIV
A
V
= 20
V
OUT
= 0V TO 10V
R
OUT
= 10k
V
+
= 12V
6106 G18
Output Voltage Swing vs
Temperature
11.10
11.05
OUTPUT VOLTAGE (V)
11.00
10.95
10.90
10.85
10.80
–50 –25
V
+
= 12V
A
V
= 100
R
IN
= 100
R
OUT
= 10k
V
SENSE
= 120mV
1100
1000
900
800
V
OUT
(mV)
700
600
500
400
300
200
100
50
25
75
0
TEMPERATURE (°C)
100
125
0
Output Voltage vs Input Sense
Voltage (0mV ≤ V
SENSE
≤ 10mV)
V
+
= 12V
A
V
= 100
R
IN
= 100
R
OUT
= 10k
V
OUT
(mV)
220
200
180
160
140
120
100
80
60
40
20
0
1
2
3
4 5 6 7
V
SENSE
(mV)
8
9
10
0
Output Voltage vs Input Sense
Voltage (0mV ≤ V
SENSE
≤ 10mV)
V
+
= 12V
A
V
= 20
R
IN
= 500
R
OUT
= 10k
0
1
2
3
4 5 6 7
V
SENSE
(mV)
8
9
10
6106 G07
6106 G19
6106 G20
6106fb
For more information
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5
