LT1999-10/LT1999-20/
LT1999-50
High Voltage, Bidirectional
Current Sense Amplifier
FeaTures
n
n
n
n
n
n
n
DescripTion
The
LT
®
1999
is a high speed precision current sense am-
plifier, designed to monitor bidirectional currents over a
wide common mode range. The LT1999 is offered in three
gain options: 10V/V, 20V/V, and 50V/V.
The LT1999 senses current via an external resistive shunt
and generates an output voltage, indicating both magnitude
and direction of the sensed current. The output voltage is
referenced halfway between the supply voltage and ground,
or an external voltage can be used to set the reference
level. With a 2MHz bandwidth and a common mode input
range of –5V to 80V, the LT1999 is suitable for monitor-
ing currents in H-Bridge motor controls, switching power
supplies, solenoid currents, and battery charge currents
from full charge to depletion.
The LT1999 operates from an independent 5V supply
and draws 1.55mA. A shutdown mode is provided for
minimizing power consumption.
The LT1999 is available in an 8-lead SOP, an 8-lead MSOP
(original pinout), or an 8-lead pinout option engineered
for FMEA.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
n
n
n
n
n
Buffered Output with 3 Gain Options:
10V/V, 20V/V, 50V/V
Gain Accuracy: 0.5% Max
Input Common Mode Voltage Range: –5V to 80V
AC CMRR > 80dB at 100kHz
Input Offset Voltage: 1.5mV Max
–3dB Bandwidth: 2MHz
Smooth, Continuous Operation Over Entire Common
Mode Range
4kV HBM Tolerant and 1kV CDM Tolerant
Low Power Shutdown <10µA
–55°C to 150°C Operating Temperature Range
8-Lead MSOP and 8-Lead SO (Narrow) Packages
8-Lead MSOP Pinout Option Engineered for FMEA
applicaTions
n
n
n
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n
High Side or Low Side Current Sensing
H-Bridge Motor Control
Solenoid Current Sense
High Voltage Data Acquisition
PWM Control Loops
Fuse/MOSFET Monitoring
Typical applicaTion
V
S
5V
1
V
+
SHDN
LT1999
V
+
2µA
8
R
G
Full Bridge Armature Current Monitor
V
OUT
2.5V
V
+IN
(20V/DIV)
V
OUT
(2V/DIV)
R
S
V
–IN
3
5V
4
0.1µF
V
+
0.8k
0.8k
4k
V
+
For more information
www.linear.com/LT1999
+
–
V
+IN
2
4k
+
–
V
SHDN
7
V
+
160k
6
160k
5
V
OUT
V
+IN
V
REF
0.1µF
TIME (10µs/DIV)
1999 TA01b
1999 TA01a
1999fd
1
LT1999-10/LT1999-20/
LT1999-50
absoluTe MaxiMuM raTings
(Note 1)
Differential Input Voltage
+IN to –IN (Notes 1, 3) ................................. ±60V, 10ms
+IN to GND, –IN to GND (Note 2) ............. –5.25V to 88V
Total Supply Voltage (V
+
to GND)................................6V
Input Voltage Pins 6 and 8 ................... V
+
+ 0.3V, –0.3V
Output Short-Circuit Duration (Note 4) ............ Indefinite
Operating Ambient Temperature (Note 5)
LT1999C ..............................................–40°C to 85°C
LT1999I................................................–40°C to 85°C
LT1999H ............................................ –40°C to 125°C
LT1999MP ......................................... –55°C to 150°C
Specified Temperature Range (Note 6)
LT1999C .................................................. 0°C to 70°C
LT1999I................................................–40°C to 85°C
LT1999H ............................................ –40°C to 125°C
LT1999MP ......................................... –55°C to 150°C
Junction Temperature ........................................... 150°C
Storage Temperature Range .................. –65°C to 150°C
pin conFiguraTion
ORIGINAL MSOP PINOUT
TOP VIEW
V
+
+IN
–IN
V
+
1
2
3
4
8
7
6
5
SHDN
OUT
REF
GND
+IN
–IN
NC
V
+
1
2
3
4
MSOP PINOUT ENGINEERED FOR FMEA
TOP VIEW
8
7
6
5
SHDN
OUT
REF
GND
V
+
1
+IN 2
–IN 3
V
+
4
TOP VIEW
8
7
6
5
SHDN
OUT
REF
GND
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
Θ
JA
= 300°C/W
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
Θ
JA
= 300°C/W
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
Θ
JA
= 190°C/W
orDer inForMaTion
LEAD FREE FINISH
LT1999CMS8-10#PBF
LT1999IMS8-10#PBF
LT1999HMS8-10#PBF
LT1999MPMS8-10#PBF
LT1999CMS8-10F#PBF
LT1999IMS8-10F#PBF
LT1999HMS8-10F#PBF
LT1999MPMS8-10F#PBF
LT1999CS8-10#PBF
LT1999IS8-10#PBF
LT1999HS8-10#PBF
LT1999MPS8-10#PBF
LT1999CMS8-20#PBF
LT1999IMS8-20#PBF
LT1999HMS8-20#PBF
LT1999MPMS8-20#PBF
TAPE AND REEL
LT1999CMS8-10#TRPBF
LT1999IMS8-10#TRPBF
LT1999HMS8-10#TRPBF
LT1999MPMS8-10#TRPBF
LT1999CMS8-10F#TRPBF
LT1999IMS8-10F#TRPBF
LT1999HMS8-10F#TRPBF
LT1999CS8-10#TRPBF
LT1999IS8-10#TRPBF
LT1999HS8-10#TRPBF
LT1999MPS8-10#TRPBF
LT1999CMS8-20#TRPBF
LT1999IMS8-20#TRPBF
LT1999HMS8-20#TRPBF
LT1999MPMS8-20#TRPBF
PART MARKING*
LTFPB
LTFPB
LTFPB
LTFQP
LTGVB
LTGVB
LTGVB
199910
199910
199910
99MP10
LTFNZ
LTFNZ
LTFNZ
LTFQQ
PACKAGE DESCRIPTION
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
SPECIFIED TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
1999fd
LT1999MPMS8-10F#TRPBF LTGVB
2
For more information
www.linear.com/LT1999
LT1999-10/LT1999-20/
LT1999-50
orDer inForMaTion
LEAD FREE FINISH
LT1999CMS8-20F#PBF
LT1999IMS8-20F#PBF
LT1999HMS8-20F#PBF
LT1999MPMS8-20F#PBF
LT1999CS8-20#PBF
LT1999IS8-20#PBF
LT1999HS8-20#PBF
LT1999MPS8-20#PBF
LT1999CMS8-50#PBF
LT1999IMS8-50#PBF
LT1999HMS8-50#PBF
LT1999MPMS8-50#PBF
LT1999CMS8-50F#PBF
LT1999IMS8-50F#PBF
LT1999HMS8-50F#PBF
LT1999MPMS8-50F#PBF
LT1999CS8-50#PBF
LT1999IS8-50#PBF
LT1999HS8-50#PBF
LT1999MPS8-50#PBF
TAPE AND REEL
LT1999CMS8-20F#TRPBF
LT1999IMS8-20F#TRPBF
LT1999HMS8-20F#TRPBF
LT1999CS8-20#TRPBF
LT1999IS8-20#TRPBF
LT1999HS8-20#TRPBF
LT1999MPS8-20#TRPBF
LT1999CMS8-50#TRPBF
LT1999IMS8-50#TRPBF
LT1999HMS8-50#TRPBF
LT1999MPMS8-50#TRPBF
LT1999CMS8-50F#TRPBF
LT1999IMS8-50F#TRPBF
LT1999HMS8-50F#TRPBF
LT1999CS8-50#TRPBF
LT1999IS8-50#TRPBF
LT1999HS8-50#TRPBF
LT1999MPS8-50#TRPBF
PART MARKING*
LTGVC
LTGVC
LTGVC
199920
199920
199920
99MP20
LTFPC
LTFPC
LTFPC
LTFQR
LTGVD
LTGVD
LTGVD
199950
199950
199950
99MP50
PACKAGE DESCRIPTION
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead MSOP FMEA Pinout
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
SPECIFIED TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 150°C
LT1999MPMS8-20F#TRPBF LTGVC
LT1999MPMS8-50F#TRPBF LTGVD
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping
container.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
The
l
denotes the specifications which apply over the full operating
temperature range, 0°C < T
A
< 70°C for C-grade parts, –40°C < T
A
< 85°C for I-grade parts, and –40°C < T
A
< 125°C for H-grade parts, otherwise
specifications are at T
A
= 25°C. V
+
= 5V, GND = 0V, V
CM
= 12V, V
REF
= floating, V
SHDN
= floating, unless otherwise specified. See Figure 2.
SYMBOL
V
SENSE
V
CM
R
IN(DIFF)
R
INCM
V
OSI
ΔV
OSI
/ΔT
A
V
A
V
Error
PARAMETER
Full-Scale Input Sense Voltage (Note 7)
V
SENSE
= V
+IN
– V
–IN
CM Input Voltage Range
Differential Input Impedance
CM Input Impedance
Input Referred Voltage Offset
l
elecTrical characTerisTics
CONDITIONS
LT1999-10
LT1999-20
LT1999-50
ΔV
INDIFF
= ±2V/Gain
ΔV
CM
= 5.5V to 80V
ΔV
CM
= –5V to 4.5V
l
l
l
l
l
l
l
MIN
–0.35
–0.2
–0.08
–5
6.4
5
3.6
–750
–1500
9.95
19.9
49.75
–0.5
TYP
MAX
0.35
0.2
0.08
80
UNITS
V
V
V
V
kΩ
MΩ
kΩ
μV
μV
μV/°C
V/V
V/V
V/V
%
1999fd
8
20
4.8
±500
5
9.6
6
750
1500
10.05
20.1
50.25
0.5
Input Referred Voltage Offset Drift
Gain
LT1999-10
LT1999-20
LT1999-50
ΔV
OUT
= ±2V
l
l
l
l
10
20
50
±0.2
Gain Error
For more information
www.linear.com/LT1999
3
LT1999-10/LT1999-20/
LT1999-50
elecTrical characTerisTics
SYMBOL
I
B
I
OS
PSRR
CMRR
PARAMETER
Input Bias Current
I(+IN) = I(–IN)
(Note 8)
Input Offset Current
I
OS
= I(+IN) – I(–IN)
(Note 8)
Supply Rejection Ratio
Sense Input Common Mode Rejection
The
l
denotes the specifications which apply over the full operating
temperature range, 0°C < T
A
< 70°C for C-grade parts, –40°C < T
A
< 85°C for I-grade parts, and –40°C < T
A
< 125°C for H-grade parts, otherwise
specifications are at T
A
= 25°C. V
+
= 5V, GND = 0V, V
CM
= 12V, V
REF
= floating, V
SHDN
= floating, unless otherwise specified. See Figure 2.
CONDITIONS
V
CM
> 5.5V
V
CM
= –5V
V
SHDN
= 0.5V, 0V < V
CM
< 80V
V
CM
> 5.5V
V
CM
= –5V
V
SHDN
= 0.5V, 0V < V
CM
< 80V
V
+
= 4.5V to 5.5V
V
CM
= –5V to 80V
V
CM
= –5V to 5.5V
V
CM
= 12V, 7V
P-P
, f = 100kHz,
V
CM
= 0V, 7V
P-P
, f = 100kHz
f = 10kHz
f = 0.1Hz to 10Hz
LT1999-10
LT1999-20
LT1999-50
V
SHDN
= 0.5V
V
SHDN
= 0.5V
LT1999-10
LT1999-20
LT1999-50
V
+
= 5.5V, V
SHDN
= 0V
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
MIN
100
–2.35
–1
–10
–2.5
68
96
96
75
80
TYP
137.5
–1.95
0.001
MAX
175
–1.5
2.5
1
10
2.5
UNITS
μA
mA
μA
μA
μA
μA
dB
dB
dB
dB
dB
nV/√Hz
μV
P-P
dB
dB
dB
77
105
120
90
100
97
8
e
n
REF
RR
Differential Input Referred Noise Voltage Density
REF Pin Rejection, V
+
= 5.5V
ΔV
REF
= 3.0V
ΔV
REF
= 3.25V
ΔV
REF
= 3.25V
REF Pin Input Impedance
Open Circuit Voltage
REF Pin Input Range (Note 9)
62
62
62
60
0.15
2.45
1
1.25
1.125
1.125
–6
V
+
– 0.5
70
70
70
80
0.4
2.5
2.5
100
0.65
2.55
2.75
V
+
– 1.25
V
+
– 1.125
V
+
– 1.125
–2
0.5
2
2
1.2
3
2.5
0.8
1
1.3
R
REF
V
REF
V
REFR
I
SHDN
V
IH
V
IL
f
3dB
SR
t
s
t
r
V
S
I
S
R
O
I
SRC
I
SNK
V
OUT
kΩ
MΩ
V
V
V
V
V
μA
V
V
MHz
MHz
MHz
V/μs
μs
μs
μs
μs
Pin Pull-Up Current
SHDN
Pin Input High
SHDN
Pin Input Low
Small Signal Bandwidth
LT1999-10
LT1999-20
LT1999-50
0.5% Settling
LT1999-10
LT1999-20
LT1999-50
l
Slew Rate
Settling Time due to Input Step, ΔV
OUT
= ±2V
Common Mode Step Recovery Time
ΔV
CM
= ±50V, 20ns
(Note 10)
Supply Voltage (Note 11)
Supply Current
V
CM
> 5.5V
V
CM
= –5V
V
+
= 5.5V, V
SHDN
= 0.5V, V
CM
> 0V
ΔI
O
= ±2mA
R
LOAD
= 50Ω to GND
R
LOAD
= 50Ω to V
+
R
LOAD
= 1kΩ to Mid-Supply
R
LOAD
= Open
R
LOAD
= 1kΩ to Mid-Supply
R
LOAD
= Open
V
SHDN
= 0V to 5V
V
SHDN
= 5V to 0V
l
l
l
l
l
l
4.5
5
1.55
5.8
3
0.15
5.5
1.9
7.1
10
40
40
250
125
400
225
V
mA
mA
μA
Ω
mA
mA
mV
mV
mV
mV
μs
μs
1999fd
l
l
l
Output Impedance
Sourcing Output Current
Sinking Output Current
Swing Output High (with Respect to V
+
)
Swing Output Low (with Respect to V
–
)
6
15
31
26
125
5
250
150
1
1
t
ON
t
OFF
Turn-On Time
Turn-Off Time
4
For more information
www.linear.com/LT1999
LT1999-10/LT1999-20/
LT1999-50
elecTrical characTerisTics
SYMBOL
V
SENSE
V
CM
R
IN(DIFF)
R
INCM
V
OSI
ΔV
OSI
/ΔT
A
V
A
V
Error
I
B
I
OS
PSRR
CMRR
PARAMETER
Full-Scale Input Sense Voltage (Note 7)
V
SENSE
= V
+IN
– V
–IN
CM Input Voltage Range
Differential Input Impedance
CM Input Impedance
Input Referred Voltage Offset
l
The
l
denotes the specifications which apply over the full operating
temperature range, –55°C < T
A
< 150°C for MP-grade parts, otherwise specifications are at T
A
= 25°C. V
+
= 5V, GND = 0V, V
CM
= 12V,
V
REF
= floating, V
SHDN
= floating, unless otherwise specified. See Figure 2.
CONDITIONS
LT1999-10
LT1999-20
LT1999-50
ΔV
INDIFF
= ±2V/GAIN
ΔV
CM
= 5.5V to 80V
ΔV
CM
= –5V to 4.5V
l
l
l
l
l
l
l
MIN
–0.35
–0.2
–0.08
–5
6.4
5
3.6
–750
–2000
9.95
19.9
49.75
–0.5
100
–2.35
–1
–10
–10
68
96
96
75
80
TYP
MAX
0.35
0.2
0.08
80
UNITS
V
V
V
V
kΩ
MΩ
kΩ
μV
μV
μV/°C
V/V
V/V
V/V
%
μA
mA
μA
μA
μA
μA
dB
dB
dB
dB
dB
nV/√Hz
μV
P-P
dB
dB
dB
8
20
4.8
±500
8
9.6
6
750
2000
10.05
20.1
50.25
0.5
180
–1.5
10
1
10
10
Input Referred Voltage Offset Drift
Gain
LT1999-10
LT1999-20
LT1999-50
ΔV
OUT
= ±2V
V
CM
> 5.5V
V
CM
= –5V
V
SHDN
= 0.5V, 0V < V
CM
< 80V
V
CM
> 5.5V
V
CM
= –5V
V
SHDN
= 0.5V, 0V < V
CM
< 80V
V
+
= 4.5V to 5.5V
V
CM
= –5V to 80V
V
CM
= –5V to 5.5V
V
CM
= 12V, 7V
P-P
, f = 100kHz,
V
CM
= 0V, 7V
P-P
, f = 100kHz
f= 10kHz
f = 0.1Hz to 10Hz
LT1999-10
LT1999-20
LT1999-50
V
SHDN
= 0.5V
V
SHDN
= 0.5V
LT1999-10
LT1999-20
LT1999-50
V
+
= 5.5V, V
SHDN
= 0V
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
10
20
50
±0.2
137.5
–1.95
0.001
Gain Error
Input Bias Current
I(+IN) = I(–IN)
(Note 8)
Input Offset Current
I
OS
= I(+IN) – I(–IN)
(Note 8)
Supply Rejection Ratio
Sense Input Common Mode Rejection
77
105
120
90
100
97
8
e
n
REF
RR
Differential Input Referred Noise Voltage Density
REF Pin Rejection, V
+
= 5.5V
ΔV
REF
= 2.75V
ΔV
REF
= 3.25V
ΔV
REF
= 3.25V
REF Pin Input Impedance
Open Circuit Voltage
REF Pin Input Range (Note 9)
62
62
62
60
0.15
2.45
0.25
1.5
1.125
1.125
–6
V
+
– 0.5
70
70
70
80
0.4
2.5
2.5
100
0.65
2.55
2.75
V
+
– 1.25
V
+
– 1.125
V
+
– 1.125
–2
0.5
2
2
1.2
3
2.5
R
REF
V
REF
V
REFR
I
SHDN
V
IH
V
IL
f
3dB
SR
t
S
kΩ
MΩ
V
V
V
V
V
μA
V
V
MHz
MHz
MHz
V/μs
μs
Pin Pull-Up Current
SHDN
Pin Input High
SHDN
Pin Input Low
Small Signal Bandwidth
LT1999-10
LT1999-20
LT1999-50
0.5% Settling
Slew Rate
Settling Time Due to Input Step, ΔV
OUT
= ±2V
1999fd
For more information
www.linear.com/LT1999
5
