LT1990
±250V
Input Range
G = 1, 10, Micropower,
Difference Amplifier
DESCRIPTIO
The LT
®
1990 is a micropower precision difference ampli-
fier with a very high common mode input voltage range. It
has pin selectable gains of 1 or 10. The LT1990 operates
over a
±250V
common mode voltage range on a
±15V
supply. The inputs are fault protected from common
mode voltage transients up to
±350V
and differential
voltages up to
±500V.
The LT1990 is ideally suited for both
high side and low side current or voltage monitoring.
On a single 5V supply, the LT1990 has an adjustable 85V
input range, 70dB min CMRR and draws less than 120µA
supply current. The rail-to-rail output maximizes the dy-
namic range, especially important for single supplies as
low as 2.7V.
The LT1990 is specified for single 3V, 5V and
±15V
supplies over both commercial and industrial temperature
ranges. The LT1990 is available in the 8-pin SO package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
FEATURES
■
■
■
■
■
■
■
■
■
■
■
■
Pin Selectable Gain of 1 or 10
High Common Mode Voltage Range:
85V Window (V
S
= 5V, 0V)
±250V
(V
S
=
±15V)
Common Mode Rejection Ratio: 70dB Min
Input Protection to
±350V
Gain Error: 0.28% Max
PSRR: 82dB Min
High Input Impedance: 2MΩ Differential,
500kΩ Common Mode
Micropower: 120µA Max Supply Current
Wide Supply Range: 2.7V to 36V
–3dB Bandwidth: 100kHz
Rail-to-Rail Output
8-Pin SO Package
APPLICATIO S
■
■
■
■
■
■
■
Battery Cell Voltage Monitoring
High Voltage Current Sensing
Signal Acquisition in Noisy Environments
Input Protection
Fault Protected Front Ends
Level Sensing
Isolation
TYPICAL APPLICATIO
+V
SOURCE
Full-Bridge Load Current Monitor
5V
LT1990
900k
7
2
1M
100k
10k
8
– +
I
L
R
S
3
V
REF
= 1.5V
4
OUT
IN
LT6650
GND FB
54.9k
1nF
40k
40k
20k
1
900k
100k
10k
1M
–12V
≤
V
CM
≤
73V
V
OUT
= V
REF
±
(10 • I
L
• R
S
)
1µF
1990fb
U
–
+
U
U
6
V
OUT
5
1990 TA01
1
LT1990
ABSOLUTE
(Notes 1, 2)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
REF 1
–IN 2
+IN 3
V
–
4
8
7
6
5
GAIN1
V
+
OUT
GAIN2
Total Supply Voltage (V
+
to V
–
) ............................... 36V
Input Voltage Range
Continuous ......................................................
±250V
Transient (0.1s) ...............................................
±350V
Differential .......................................................
±500V
Output Short-Circuit Duration (Note 3) ............ Indefinite
Operating Temperature Range (Note 4)
LT1990C .............................................. –40°C to 85°C
LT1990I ............................................... –40°C to 85°C
LT1990H ........................................... –40°C to 125°C
Specified Temperature Range (Note 5)
LT1990C .............................................. –40°C to 85°C
LT1990I ............................................... –40°C to 85°C
LT1990H ........................................... –40°C to 125°C
Junction Temperature ........................................... 150°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec.)................. 300°C
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 190°C/W
ORDER PART NUMBER
LT1990CS8
LT1990IS8
LT1990HS8
LT1990ACS8
LT1990AIS8
LT1990AHS8
S8 PART MARKING
1990
1990I
1990H
1990A
1990AI
1990AH
Order Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
3V/5V ELECTRICAL CHARACTERISTICS
V
S
= 3V, 0V; V
S
= 5V, 0V; R
L
= 10k, V
CM
= V
REF
= half supply, G = 1, 10, T
A
= 25°C, unless otherwise noted. (Note 6)
SYMBOL
G
∆G
PARAMETER
Gain
Gain Error
CONDITIONS
Pins 5 and 8 = Open
Pins 5 and 8 = V
REF
V
OUT
= 0.5V to (+Vs) –0.75V
LT1990, G = 1
LT1990A, G = 1
G = 10, V
S
= 5V, 0V
V
S
= 5V, 0V; V
OUT
= 0.5V to 4.25V
G=1
G = 10
Guaranteed by CMRR
V
S
= 3V, 0V; V
REF
= 1.25V
V
S
= 5V, 0V; V
REF
= 1.25V
V
S
= 5V, 0V; V
REF
= 2.5V
V
S
= 3V, 0V (Note 7)
V
CM
= –5V to 25V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V
V
CM
= –5V to 80V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V (Note 7)
V
CM
= –38V to 47V, V
REF
= 2.5V
LT1990
LT1990A
–5
–5
–38
MIN
TYP
1
10
0.4
0.07
0.2
0.001
0.01
0.6
0.28
0.8
0.005
%
%
%
%
%
V
V
V
MAX
UNITS
GNL
Gain Nonlinearity
V
CM
Input Voltage Range
25
80
47
CMRR
Common Mode Rejection Ratio
RTI (Referred to Input)
60
70
68
75
60
70
68
75
60
70
68
75
1990fb
2
U
dB
dB
dB
dB
dB
dB
W
U
U
W W
W
LT1990
3V/5V ELECTRICAL CHARACTERISTICS
V
S
= 3V, 0V; V
S
= 5V, 0V; R
L
= 10k, V
CM
= V
REF
= half supply, G = 1, 10, T
A
= 25°C, unless otherwise noted. (Note 6)
SYMBOL
V
OS
e
n
R
IN
PSRR
I
S
V
OL
V
OH
PARAMETER
Offset Voltage, RTI
Input Noise Voltage, RTI
Noise Voltage Density, RTI
Input Resistance
Power Supply Rejection Ratio, RTI
Minimum Supply Voltage
Supply Current
Output Voltage Swing LOW
Output Voltage Swing HIGH
CONDITIONS
G = 1, 10
f
O
= 0.1Hz to 10Hz
f
O
= 1kHz
Differential
Common Mode
V
S
= 2.7V to 12.7V, V
CM
= V
REF
= 1.25V
Guaranteed by PSRR
(Note 8)
–IN = V
+
, +IN = Half Supply (Note 8)
–IN = 0V, +IN = Half Supply
V
S
= 3V, 0V, Below V
+
V
S
= 5V, 0V, Below V
+
Short to GND (Note 9)
Short to V
+
(Note 9)
G=1
G = 10
G = 1, V
S
= 5V, 0V, V
OUT
= 0.5V to 4.5V
4V Step, G = 1, V
S
= 5V, 0V
G=1
G = 10
4
13
80
MIN
TYP
0.8
22
1
2
0.5
92
2.4
105
30
100
120
8
20
100
6.5
0.5
45
1
±
0.0007
1
±
0.007
2.7
120
50
150
175
MAX
3
UNITS
mV
µV
P-P
µV/√Hz
MΩ
MΩ
dB
V
µA
mV
mV
mV
mA
mA
kHz
kHz
V/µs
µs
I
SC
BW
SR
AV
REF
Output Short-Circuit Current
Bandwidth (–3dB)
Slew Rate
Settling Time to 0.01%
Reference Gain to Output
The
●
denotes the specifications which apply over the temperature range of 0
°
C
≤
T
A
≤
70
°
C. V
S
= 3V, 0V; V
S
= 5V, 0V; R
L
= 10k,
V
CM
= V
REF
= half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
∆G
PARAMETER
Gain Error
CONDITIONS
V
OUT
= 0.5V to (+V
S
) – 0.75V
LT1990, G = 1
LT1990A, G = 1
G = 10
G = 1 (Note 10)
G = 10 (Note 10)
Guaranteed by CMRR
V
S
= 3V, 0V, V
REF
= 1.25V
V
S
= 5V, 0V, V
REF
= 1.25V
V
S
= 5V, 0V, V
REF
= 2.5V
V
S
= 3V, 0V (Note 7)
V
CM
= –5V to 25V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V
V
CM
= –5V to 80V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V (Note 7)
V
CM
= –38V to 47V, V
REF
= 2.5V
LT1990
LT1990A
●
●
●
●
●
●
●
●
LT1990C/LT1990I
MIN
TYP
MAX
0.65
0.33
0.90
2
7
–5
–5
–37
10
20
25
80
48
UNITS
%
%
%
ppm/°C
ppm/°C
V
V
V
G/T
V
CM
Gain vs Temperature
Input Voltage Range
CMRR
Common Mode Rejection Ratio, RTI
●
●
58
68
dB
dB
●
●
58
68
dB
dB
●
●
58
68
dB
dB
1990fb
3
LT1990
3V/5V ELECTRICAL CHARACTERISTICS
SYMBOL
V
OS
PARAMETER
Input Offset Voltage, RTI
CONDITIONS
V
S
= 3V, 0V
G = 1, 10
V
S
= 5V, 0V
G = 1, 10
V
OS
/T
V
OSH
PSRR
Input Offset Voltage Drift, RTI
Input Offset Voltage Hysteresis, RTI
Power Supply Rejection Ratio, RTI
(Note 10)
(Note 11)
V
S
= 2.7V to 12.7V
V
CM
= V
REF
= 1.25V
G = 1, 10
Guaranteed by PSRR
(Note 8)
–IN = V
+
, +IN = Half Supply (Note 8)
–IN = 0V, +IN = Half Supply
V
S
= 3V, 0V, Below V
+
V
S
= 5V, 0V, Below V
+
Short to GND (Note 9)
Short to V
+
(Note 9)
●
●
●
●
The
●
denotes the specifications which apply over the temperature range of 0
°
C
≤
T
A
≤
70
°
C. V
S
= 3V, 0V; V
S
= 5V, 0V; R
L
= 10k,
V
CM
= V
REF
= half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
LT1990C/LT1990I
MIN
TYP
MAX
4.1
4.1
5
230
22
UNITS
mV
mV
µV/°C
µV
●
●
●
●
●
●
●
●
78
2.7
150
60
180
205
3
11
dB
V
µA
mV
mV
mV
mA
mA
Minimum Supply Voltage
I
S
V
OL
V
OH
Supply Current
Output Voltage Swing LOW
Output Voltage Swing HIGH
I
SC
Output Short-Circuit Current
The
●
denotes the specifications which apply over the temperature range of –40°C
≤
T
A
≤
85°C. V
S
= 3V, 0V; V
S
= 5V, 0V; R
L
= 10k,
V
CM
= V
REF
= half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
∆G
PARAMETER
Gain Error
CONDITIONS
V
OUT
= 0.5V to (+V
S
) – 0.75V
LT1990, G = 1
LT1990A, G = 1
G = 10
G = 1 (Note 10)
G = 10 (Note 10)
Guaranteed by CMRR
V
S
= 3V, 0V, V
REF
= 1.25V
V
S
= 5V, 0V, V
REF
= 1.25V
V
S
= 5V, 0V, V
REF
= 2.5V
V
S
= 3V, 0V (Note 7)
V
CM
= –5V to 25V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V
V
CM
= –5V to 80V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V (Note 7)
V
CM
= –38V to 47V, V
REF
= 2.5V
LT1990
LT1990A
●
●
●
●
●
●
●
●
LT1990C/LT1990I
MIN
TYP
MAX
0.67
0.35
0.95
2
7
–5
–5
–37
10
20
25
80
48
UNITS
%
%
%
ppm/°C
ppm/°C
V
V
V
G/T
V
CM
Gain vs Temperature
Input Voltage Range
CMRR
Common Mode Rejection Ratio, RTI
●
●
57
67
dB
dB
●
●
57
67
dB
dB
●
●
57
67
dB
dB
1990fb
4
LT1990
3V/5V ELECTRICAL CHARACTERISTICS
SYMBOL
V
OS
PARAMETER
Input Offset Voltage, RTI
CONDITIONS
V
S
= 3V, 0V
G = 1, 10
V
S
= 5V, 0V
G = 1, 10
V
OS
/T
V
OSH
PSRR
Input Offset Voltage Drift, RTI
Input Offset Voltage Hysteresis, RTI
Power Supply Rejection Ratio, RTI
Minimum Supply Voltage
I
S
V
OL
V
OH
Supply Current
Output Voltage Swing LOW
Output Voltage Swing HIGH
(Note 10)
(Note 11)
V
S
= 2.7V to 12.7V
V
CM
= V
REF
= 1.25V
Guaranteed by PSRR
(Note 8)
–IN = V
+
, +IN = Half Supply (Note 8)
–IN = 0V, +IN = Half Supply
V
S
= 3V, 0V, Below V
+
V
S
= 5V, 0V, Below V
+
Short to GND (Note 9)
Short to V
+
(Note 9)
●
●
●
●
●
●
●
●
●
●
●
●
The
●
denotes the specifications which apply over the temperature range of –40°C
≤
T
A
≤
85°C. V
S
= 3V, 0V; V
S
= 5V, 0V;
R
L
= 10k, V
CM
= V
REF
= half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
LT1990C/LT1990I
MIN
TYP
MAX
4.5
4.5
5
230
76
2.7
170
70
200
275
2
8
22
UNITS
mV
mV
µV/°C
µV
dB
V
µA
mV
mV
mV
mA
mA
I
SC
Output Short-Circuit Current
3V/5V ELECTRICAL CHARACTERISTICS
The
●
denotes the specifications which apply over the temperature range of –40°C
≤
T
A
≤
125°C. V
S
= 3V, 0V; V
S
= 5V, 0V; R
L
= 10k,
V
CM
= V
REF
= half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
∆G
PARAMETER
Gain Error
CONDITIONS
V
OUT
= 0.5V to (+V
S
) – 0.75V
LT1990, G = 1
LT1990A, G = 1
G = 10
G = 1 (Note 10)
G = 10 (Note 10)
Guaranteed by CMRR
V
S
= 3V, 0V, V
REF
= 1.25V
V
S
= 5V, 0V, V
REF
= 1.25V
V
S
= 5V, 0V, V
REF
= 2.5V
V
S
= 3V, 0V (Note 7)
V
CM
= –5V to 25V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V
V
CM
= –5V to 80V, V
REF
= 1.25V
LT1990
LT1990A
V
S
= 5V, 0V (Note 7)
V
CM
= –38V to 47V, V
REF
= 2.5V
LT1990
LT1990A
●
●
●
●
●
●
●
●
MIN
LT1990H
TYP
MAX
0.69
0.37
0.97
2
7
10
20
25
80
48
UNITS
%
%
%
ppm/°C
ppm/°C
V
V
V
G/T
V
CM
Gain vs Temperature
Input Voltage Range
–5
–5
–37
CMRR
Common Mode Rejection Ratio, RTI
●
●
56
66
dB
dB
●
●
56
66
dB
dB
●
●
56
66
dB
dB
1990fb
5
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