LT1990 [Linear]
250V Input Range G = 1, 10, Micropower, Difference Amplifier; 250V输入范围G = 1 , 10 ,微功耗,差分放大器型号: | LT1990 |
厂家: | Linear |
描述: | 250V Input Range G = 1, 10, Micropower, Difference Amplifier |
文件: | 总16页 (文件大小:223K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LT1990
±250V Input Range
G = 1, 10, Micropower,
Difference Amplifier
DESCRIPTIO
U
U
APPLICATIO S
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
voltagesupto±500V.TheLT1990isideallysuitedforboth
high side and low side current or voltage monitoring.
■
Pin Selectable Gain of 1 or 10
■
High Common Mode Voltage Range:
85V Window (VS = 5V, 0V)
±250V (VS = ±15V)
Common Mode Rejection Ratio: 70dB Min
Input Protection to ±350V
■
■
■
Gain Error: 0.28% Max
PSRR: 82dB Min
■
■
High Input Impedance: 2MΩ Differential,
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.
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
■
■
■
The LT1990 is specified for single 3V, 5V and ±15V
suppliesoverbothcommercialandindustrialtemperature
ranges. The LT1990 is available in the 8-pin SO package.
FEATURES
■
, LTC and LT are registered trademarks of Linear Technology Corporation.
Battery Cell Voltage Monitoring
High Voltage Current Sensing
Signal Acquisition in Noisy Environments
Input Protection
Fault Protected Front Ends
Level Sensing
Isolation
■
■
■
■
■
■
U
TYPICAL APPLICATIO
Full-Bridge Load Current Monitor
+V
SOURCE
5V
LT1990
900k
10k
8
6
5
7
2
100k
1M
1M
–
+
R
S
V
OUT
+
–
3
4
V
REF
= 1.5V
1nF
I
L
10k
OUT
LT6650
GND FB
IN
54.9k
40k
900k
100k
40k
20k
–12V ≤ V ≤ 73V
CM
OUT
1990 TA01
1
V
= V ± (10 • I • R )
REF L S
1µF
1990f
1
LT1990
W W U W
U
W
U
ABSOLUTE AXI U RATI GS
(Notes 1, 2)
PACKAGE/ORDER I FOR ATIO
Total Supply Voltage (V+ to V–)............................... 36V
Input Voltage Range
ORDER PART
NUMBER
TOP VIEW
Continuous ...................................................... ±250V
Transient (0.1s) ............................................... ±350V
Differential ....................................................... ±500V
Output Short-Circuit Duration (Note 3)............ Indefinite
Operating Temperature Range (Note 4) ...–40°C to 85°C
Specified Temperature Range (Note 5)....–40°C to 85°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10 sec.)................. 300°C
LT1990CS8
LT1990IS8
LT1990ACS8
LT1990AIS8
REF
–IN
+IN
1
2
3
4
8
7
6
5
GAIN1
+
V
OUT
–
V
GAIN2
S8 PART
MARKING
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 190°C/W
1990
1990A
1990I
1990AI
3V/5V ELECTRICAL CHARACTERISTICS
VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, TA = 25°C, unless otherwise noted. (Note 6)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
G
Gain
Pins 5 and 8 = Open
Pins 5 and 8 = GND
1
10
∆G
Gain Error
V
= 0.5V to (+Vs) –0.75V
OUT
LT1990, G = 1
LT1990A, G = 1
G = 10, V = 5V, 0V
0.4
0.07
0.2
0.6
0.28
0.8
%
%
%
S
GNL
Gain Nonlinearity
V = 5V, 0V; V
G = 1
G = 10
= 0.5V to 4.25V
OUT
S
0.001 0.005
0.01
%
%
V
Input Voltage Range
Guaranteed by CMRR
V = 3V, 0V; V = 1.25V
CM
–5
–5
–38
25
80
47
V
V
V
S
REF
V = 5V, 0V; V = 1.25V
S
REF
V = 5V, 0V; V = 2.5V
S
REF
CMRR
Common Mode Rejection Ratio
RTI (Referred to Input)
V = 3V, 0V (Note 7)
S
V
CM
= –5V to 25V, V
= 1.25V
= 1.25V
REF
LT1990
LT1990A
60
70
68
75
dB
dB
V = 5V, 0V
S
V
CM
= –5V to 80V, V
REF
LT1990
LT1990A
60
70
68
75
dB
dB
V = 5V, 0V (Note 7)
S
V
= –38V to 47V, V = 2.5V
CM
REF
LT1990
LT1990A
60
70
68
75
dB
dB
V
Offset Voltage, RTI
G = 1, 10
0.8
22
1
3
mV
OS
e
Input Noise Voltage, RTI
Noise Voltage Density, RTI
f = 0.1Hz to 10Hz
O
µV
P-P
n
f = 1kHz
O
µV/√Hz
1990f
2
LT1990
3V/5V ELECTRICAL CHARACTERISTICS
VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, TA = 25°C, unless otherwise noted. (Note 6)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
R
Input Resistance
Differential
Common Mode
2
0.5
MΩ
MΩ
IN
PSRR
Power Supply Rejection Ratio, RTI
Minimum Supply Voltage
Supply Current
V = 2.7V to 12.7V, V = V = 1.25V
80
92
2.4
105
30
dB
V
S
CM
REF
Guaranteed by PSRR
2.7
120
50
I
(Note 8)
µA
mV
S
+
V
V
Output Voltage Swing LOW
Output Voltage Swing HIGH
–IN = V , +IN = Half Supply (Note 8)
OL
OH
–IN = 0V, +IN = Half Supply
+
V = 3V, 0V, Below V
V = 5V, 0V, Below V
S
100
120
150
175
mV
mV
S
+
I
Output Short-Circuit Current
Bandwidth (–3dB)
Short to GND (Note 9)
Short to V (Note 9)
4
13
8
20
mA
mA
SC
+
BW
SR
G = 1
G = 10
100
6.5
kHz
kHz
Slew Rate
G = 1, V = 5V, 0V, V
= 0.5V to 4.5V
OUT
0.5
45
V/µs
µs
S
Settling Time to 0.01%
Reference Gain to Output
4V Step, G = 1, V = 5V, 0V
S
AV
1 ± 0.0007
REF
The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k,
VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
∆G
Gain Error
V
OUT
= 0.5V to (+V ) – 0.75V
S
LT1990, G = 1
LT1990A, G = 1
G = 10
●
●
●
0.65
0.33
0.90
%
%
%
G/T
Gain vs Temperature
Input Voltage Range
G = 1 (Note 10)
G = 10 (Note 10)
●
●
2
7
10
20
ppm/°C
ppm/°C
V
Guaranteed by CMRR
CM
V = 3V, 0V, V = 1.25V
●
●
●
–5
–5
–37
25
80
48
V
V
V
S
REF
V = 5V, 0V, V = 1.25V
S
REF
V = 5V, 0V, V = 2.5V
S
REF
CMRR
Common Mode Rejection Ratio, RTI
V = 3V, 0V (Note 7)
S
V
= –5V to 25V, V = 1.25V
CM
REF
LT1990
LT1990A
●
●
58
68
dB
dB
V = 5V, 0V
S
V
= –5V to 80V, V = 1.25V
CM
REF
LT1990
LT1990A
●
●
58
68
dB
dB
V = 5V, 0V (Note 7)
S
V
= –38V to 47V, V = 2.5V
CM
REF
LT1990
LT1990A
●
●
58
68
dB
dB
V
Input Offset Voltage, RTI
V = 3V, 0V
G = 1, 10
●
●
OS
S
4.1
4.1
mV
mV
V = 5V, 0V
●
●
S
G = 1, 10
1990f
3
LT1990
3V/5V ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k,
VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
PARAMETER
CONDITIONS
(Note 10)
MIN
TYP
5
MAX
UNITS
µV/°C
µV
V
V
/T
OS
OSH
Input Offset Voltage Drift, RTI
Input Offset Voltage Hysteresis, RTI
Power Supply Rejection Ratio, RTI
●
●
22
(Note 11)
230
PSRR
V = 2.7V to 12.7V
S
V
= V = 1.25V
CM
REF
G = 1, 10
●
●
●
●
78
dB
V
Minimum Supply Voltage
Supply Current
Guaranteed by PSRR
2.7
150
60
I
(Note 8)
µA
mV
S
+
V
V
Output Voltage Swing LOW
Output Voltage Swing HIGH
–IN = V , +IN = Half Supply (Note 8)
OL
OH
–IN = 0V, +IN = Half Supply
+
V = 3V, 0V, Below V
●
●
180
205
mV
mV
S
+
V = 5V, 0V, Below V
S
I
Output Short-Circuit Current
Short to GND (Note 9)
Short to V (Note 9)
●
●
3
11
mA
mA
SC
+
The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k,
VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
PARAMETER
CONDITIONS
V = 0.5V to (+V ) – 0.75V
OUT
MIN
TYP
MAX
UNITS
∆G
Gain Error
S
LT1990, G = 1
LT1990A, G = 1
G = 10
●
●
●
0.67
0.35
0.95
%
%
%
G/T
Gain vs Temperature
Input Voltage Range
G = 1 (Note 10)
G = 10 (Note 10)
●
●
2
7
10
20
ppm/°C
ppm/°C
V
Guaranteed by CMRR
CM
V = 3V, 0V, V = 1.25V
●
●
●
–5
–5
–37
25
80
48
V
V
V
S
REF
V = 5V, 0V, V = 1.25V
S
REF
V = 5V, 0V, V = 2.5V
S
REF
CMRR
Common Mode Rejection Ratio, RTI
V = 3V, 0V (Note 7)
S
V
CM
= –5V to 25V, V = 1.25V
REF
LT1990
LT1990A
●
●
57
67
dB
dB
V = 5V, 0V
S
V
CM
= –5V to 80V, V = 1.25V
REF
LT1990
LT1990A
●
●
57
67
dB
dB
V = 5V, 0V (Note 7)
S
V
CM
= –38V to 47V, V = 2.5V
REF
LT1990
LT1990A
●
●
57
67
dB
dB
V
Input Offset Voltage, RTI
V = 3V, 0V
G = 1, 10
●
●
OS
OS
S
4.5
mV
V = 5V, 0V
●
●
S
G = 1, 10
(Note 10)
(Note 11)
4.5
22
mV
µV/°C
µV
V
V
/T
Input Offset Voltage Drift, RTI
●
●
5
Input Offset Voltage Hysteresis, RTI
Power Supply Rejection Ratio, RTI
230
OSH
PSRR
V = 2.7V to 12.7V
S
V
CM
= V = 1.25V
●
76
dB
REF
1990f
4
LT1990
3V/5V ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C. VS = 3V, 0V; VS = 5V, 0V;
RL = 10k, VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
PARAMETER
CONDITIONS
Guaranteed by PSRR
(Note 8)
MIN
TYP
MAX
2.7
UNITS
V
Minimum Supply Voltage
Supply Current
●
●
●
I
170
70
µA
S
+
V
V
Output Voltage Swing LOW
Output Voltage Swing HIGH
–IN = V , +IN = Half Supply (Note 8)
mV
OL
OH
–IN = 0V, +IN = Half Supply
+
V = 3V, 0V, Below V
S
●
●
200
225
mV
mV
S
+
V = 5V, 0V, Below V
I
Output Short-Circuit Current
Short to GND (Note 9)
Short to V (Note 9)
●
●
2
8
mA
mA
SC
+
±15V ELECTRICAL CHARACTERISTICS
VS = ±15V, RL = 10k, VCM = VREF = 0V, G = 1, 10, TA = 25°C, unless otherwise noted. (Note 6)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
G
Gain
Pins 5 and 8 = Open
1
10
Pins 5 and 8 = V
REF
∆G
Gain Error
V
= ±10V
OUT
LT1990, G = 1
LT1990A, G = 1
G = 10
0.4
0.07
0.2
0.6
0.28
0.8
%
%
%
GNL
Gain Nonlinearity
V
= ±10V
OUT
G = 1
G = 10
Guaranteed by CMRR
= –250V to 250V
0.0008 0.002
%
%
0.005
0.02
V
Input Voltage Range
–250
250
V
CM
CMRR
Common Mode Rejection Ratio, RTI
V
CM
LT1990
LT1990A
60
70
68
75
dB
dB
V
Offset Voltage, RTI
G = 1, 10
0.9
22
1
5.2
mV
OS
e
Input Noise Voltage, RTI
Noise Voltage Density, RTI
Input Resistance
f = 0.1Hz to 10Hz
O
µV
P-P
n
f = 1kHz
O
µV/√Hz
R
Differential
Common Mode
2
0.5
MΩ
MΩ
IN
PSRR
Power Supply Rejection Ratio, RTI
Minimum Supply Voltage
Supply Current
V = ±1.35V to ±18V
82
100
±1.2
140
dB
V
S
Guaranteed by PSRR
±1.35
I
180
µA
V
S
V
Output Voltage Swing
±14.5 ±14.79
OUT
–
I
Output Short-Circuit Current
Short to V
Short to V
6
15
9
22
mA
mA
SC
+
BW
SR
Bandwidth
G = 1
G = 10
105
7
kHz
kHz
Slew Rate
G = 1, V
= ±10V
0.3
0.55
60
V/µs
µs
OUT
Settling Time to 0.01%
Reference Gain to Output
10V Step, G = 1
AV
REF
1 ± 0.0007
1990f
5
LT1990
±15V ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = ±15V, RL = 10k, VCM = VREF = 0V,
G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
PARAMETER
CONDITIONS
V = ±10V
OUT
MIN
TYP
MAX
UNITS
∆G
Gain Error
LT1990, G = 1
LT1990A, G = 1
G = 10
●
●
●
0.65
0.33
0.9
%
%
%
GNL
G/T
Gain Nonlinearity
V
G = 1
G = 10
= ±10V
OUT
●
●
0.0025
0.025
%
%
Gain vs Temperature
G = 1 (Note 10)
G = 10 (Note 10)
●
●
2
7
10
20
ppm/°C
ppm/°C
V
Input Voltage Range
Guaranteed by CMRR
●
–250
250
V
CM
CMRR
Common Mode Rejection Ratio, RTI
V
= –250V to 250V
CM
LT1990
LT1990A
●
●
59
68
dB
dB
V
V
V
Input Offset Voltage, RTI
Input Offset Voltage Drift, RTI
Input Offset Voltage Hysteresis, RTI
Power Supply Rejection Ratio, RTI
Minimum Supply Voltage
Supply Current
G = 1, 10
(Note 10)
(Note 11)
●
●
●
6.2
22
mV
µV/°C
µV
OS
OS
/T
5
250
OSH
PSRR
V = ±1.35V to ±16V
S
80
dB
Guaranteed by PSRR
●
●
●
±1.35
V
I
230
µA
S
V
Output Voltage Swing
±14.4
V
OUT
–
I
Output Short-Circuit Current
Short to V
Short to V
●
●
5
13
mA
mA
SC
+
SR
Slew Rate
G = 1, V
= ±10V
●
0.25
V/µs
OUT
1990f
6
LT1990
±15V ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C. VS = ±15V, RL = 10k, VCM = VREF = 0V,
G = 1, 10, unless otherwise noted. (Notes 4, 6)
SYMBOL
PARAMETER
CONDITIONS
V = ±10V
OUT
MIN
TYP
MAX
UNITS
∆G
Gain Error
LT1990, G = 1
LT1990A, G = 1
G = 10
●
●
●
0.67
0.35
0.9
%
%
%
GNL
G/T
Gain Nonlinearity
V
G = 1
G = 10
= ±10V
OUT
●
●
0.003
0.03
%
%
Gain vs Temperature
G = 1 (Note 10)
G = 10 (Note 10)
●
●
2
7
10
20
ppm/°C
ppm/°C
V
Input Voltage Range
Guaranteed by CMRR
●
–250
250
V
CM
CMRR
Common Mode Rejection Ratio, RTI
V
= –250V to 250V
CM
LT1990
LT1990A
●
●
58
67
dB
dB
V
V
V
Input Offset Voltage, RTI
Input Offset Voltage Drift, RTI
Input Offset Voltage Hysteresis, RTI
Power Supply Rejection Ratio, RTI
Minimum Supply Voltage
Supply Current
G = 1, 10
(Note 10)
(Note 11)
●
●
●
●
●
6.7
22
mV
µV/°C
µV
OS
OS
/T
5
250
OSH
PSRR
V = ±1.35V to ±18V
S
78
dB
Guaranteed by PSRR
±1.35
V
I
280
µA
S
V
Output Voltage Swing
●
±14.3
V
OUT
–
I
Output Short-Circuit Current
Short to V
Short to V
●
●
3
10
mA
mA
SC
+
SR
Slew Rate
G = 1, V
= ±10V
●
0.2
V/µs
OUT
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 6: G = 10 limits are guaranteed by correlation to G = 1 tests and gain
error tests at G = 10.
Note 2: ESD (Electrostatic Discharge) sensitive device. Extensive use of
ESD protection devices are used internal to the LT1990, however, high
electrostatic discharge can damage or degrade the device. Use proper ESD
handling precautions.
Note 3: A heat sink may be required to keep the junction temperature
below absolute maximum.
Note 4: The LT1990C/LT1990I are guaranteed functional over the
operating temperature range of –40°C to 85°C.
Note 5: The LT1990C is guaranteed to meet the specified performance
from 0°C to70°C and 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 LT1990I is guaranteed to meet
specified performance from –40°C to 85°C.
Note 7: Limits are guaranteed by correlation to –5V to 80V CMRR tests.
Note 8: V = 3V limits are guaranteed by correlation to V = 5V and
S
S
V = ±15V tests.
S
Note 9: V = 5V limits are guaranteed by correlation to V = 3V and
S
S
V = ±15V tests.
S
Note 10: This parameter is not 100% tested.
Note 11: Hysteresis in offset voltage is created by package stress that
differs depending on whether the IC was previously at a higher or lower
temperature. Offset voltage hysteresis is always measured at 25°C, but the
IC is cycled to 85°C I-grade (or 70°C C-grade) or –40°C I-grade (0°C
C-grade) before successive measurement.
1990f
7
LT1990
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Output Voltage Swing
vs Load Current
Supply Current
Supply Current
vs Temperature
vs Supply Voltage
+
220
200
180
160
140
120
100
80
– 0.01
– 0.1
–1
150
140
130
120
110
100
90
V
V
V
= V
= 1.25V
V = ±2.5V
S
V
= 5V, 0V
REF
OUT
S
–
T
= –55°C
A
= 0V
–IN = 0V
G = 1
T
= 125°C
= 85°C
A
T
SOURCING
(+IN = 2.5V)
T
= 125°C
A
A
T
= 25°C
T
= 25°C
A
A
T
= 25°C
A
T
T
= –40°C
= –55°C
A
A
+1
+0.1
T
= 125°C
A
SINKING
(+IN = –2.5V)
80
T
= –55°C
A
60
70
–
40
60
+0.01
V
V
0
5
15 20 25 30
SUPPLY VOLTAGE (V)
40
10
35
0.001
0.01
0.1
1
10
100
–50 –25
0
25
50
125
75 100
OUTPUT CURRENT (mA)
TEMPERATURE (°C)
1990 G03
1990 G01
1990 G02
Output Voltage vs
Input Voltage, G = 1
Output Voltage Swing vs
Supply Voltage
Output Voltage vs
Input Voltage, G = 10
+
+
+
V
–0.01
–0.1
–1
V
–0.01
–0.1
–1
–0.01
–0.1
T
= –55°C
= 125°C
V
= ±2.5V
A
T
= –55°C
V
= ±2.5V
S
A
S
+
G = 1
G = 1, V = V
+IN
G = 10
NO LOAD
T
NO LOAD
A
T
A
= 125°C
+
T
= 25°C
G = 10, V = V /10
A
T = 25°C
A
+IN
G = 1
G = 10
OUTPUT FULLY
SATURATED
V
V
= 0V
= 0V
–IN
REF
NO LOAD
T
= 25°C
A
OUTPUT FULLY
SATURATED
G = 10
+1
+0.1
+1
G = 1
–
G = 10, V = V /10
+IN
+0.1
T
= 25°C
A
T
= 25°C
A
–
G = 1, V = V
+IN
+0.1
T
= 125°C
A
T
= 125°C
A
T
= –55°C
A
T
= –55°C
A
–
–
–
V
+0.01
V
V
+0.01
+0.01
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
DIFFERENTIAL INPUT VOLTAGE (±V)
1990 G04
0
0.2
0.4
0.6
0.8
1.0
0
2
4
6
8
10 12 14 16
DIFFERENTIAL INPUT VOLTAGE (±V)
SUPPLY VOLTAGE (±V)
1990 G05
1990 G06
Input Voltage Range vs Split
Supply Voltage
Output Short-Circuit Current
vs Supply Voltage
Input Voltage Range vs Single
Supply Voltage
25
20
250
200
150
100
50
300
200
–
V
= 0V
V
= 0V
REF
T
= –40°C TO 85°C
T = –40°C TO 85°C
A
A
SOURCE
15
T
= –55°C
A
V
= 4V
REF
10
T
= 25°C
V
= 1.25V
A
100
REF
5
T
= 125°C
A
0
V
= 2.5V
REF
0
–5
SINK
–10
–15
–20
–25
–30
T
= 125°C
A
–100
–200
–300
V
= 1.25V
= 2.5V
REF
0
T
= –55°C
V
A
REF
–50
–100
T
= 25°C
V
= 4V
A
REF
0
2
4
6
8
10 12 14 16
3
7
9
11
13
15
1
7
9
11
13
15
5
3
5
POSITIVE SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (±V)
SUPPLY VOLTAGE (±V)
1990 G07
1990 G08
1990 G09
1990f
8
LT1990
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Common Mode Rejection Ratio
vs Frequency
Gain vs Frequency
50
40
100
90
80
70
60
50
40
30
20
10
0
V
T
= 5V, 0V
= 25°C
V
T
= 5V, 0V
S
A
S
A
= 25°C
G = 1 OR 10
30
REFERRED TO INPUT
G = 10
G = 1
20
10
0
–10
–20
–30
–40
–50
100
1k
10k
100k
1M
10k
1k
FREQUENCY (Hz)
100
100k 200k
FREQUENCY (Hz)
1990 G10
1990 G12
–3dB Bandwidth vs Supply
Voltage, G = 1
Slew Rate vs Supply Voltage,
G = 1
–3dB Bandwidth vs Supply
Voltage, G = 10
1.0
0.8
0.6
0.4
0.2
0
120
115
110
105
100
95
8
7
6
5
4
3
T
A
= 25°C
T
A
= 25°C
T = 25°C
A
R
L
= 10k
T
= –55°C
= 125°C
A
T
A
= –55°C
T
A
–SR
+SR
T
A
= 125°C
T
A
= 25°C
T
A
= 25°C
90
85
80
75
70
6
8
6
8
8
0
2
4
10 12 14 16
0
2
4
10 12 14 16
0
2
4
6
10 12 14 16
SUPPLY VOLTAGE (±V)
SUPPLY VOLTAGE (±V)
SUPPLY VOLTAGE (±V)
1990 G13
1990 G14
1990 G15
Slew Rate vs Supply Voltage,
G = 10
Slew Rate vs Temperature
G = 1
Slew Rate vs Temperature
G = 10
1.0
0.8
0.6
0.4
0.2
0
0.6
0.5
0.4
0.3
0.2
0.1
0
0.5
0.4
0.3
0.2
0.1
0
T
= 25°C
= 10k
V
= ±15V
= 10k
V
= ±15V
= 10k
A
L
S
L
S
L
R
R
R
–SR
–SR
–SR
+SR
+SR
+SR
8
50
TEMPERATURE (°C)
100 125
50
TEMPERATURE (°C)
100 125
0
2
4
6
10 12 14 16
–50 –25
0
25
75
–50 –25
0
25
75
SUPPLY VOLTAGE (±V)
1990 G17
1990 G18
1990 G16
1990f
9
LT1990
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Power Supply Rejection Ratio
Output Impedance vs Frequency
vs Frequency
Warm-Up Drift vs Time
70
60
60
40
5k
1k
V
T
= 5V, 0V
= 25°C
V
T
= ±15V
= 25°C
S
S
A
A
G = 1
REFERRED TO INPUT
50
G = 10
40
20
30
G = 10
G = 1
20
100
10
1
0
10
0
–20
–40
–60
–10
–20
–30
–40
V
= 5V, 0V
= 25°C
S
A
T
0
10
20
30
40
50
100
1k
10k
100k 200k
10
100
1k
10k
100k 200k
TIME AFTER POWER-UP (S)
FREQUENCY (Hz)
FREQUENCY (Hz)
1990 G19
1990 G20
1990 G21
Settling Time vs Output Step,
G = 10
Voltage Noise Density
vs Frequency
Settling Time vs Output Step,
G = 1
60
50
40
30
20
320
300
280
260
240
220
200
180
160
140
10000
1000
100
V
T
= ±1.5V TO ±15V
= 25°C
V
= ±15V
= 10k
S
A
V
= ±15V
= 10k
S
L
S
L
R
R
0.01% OF
STEP
0.01% OF
STEP
0.01% OF
STEP
0.01% OF
STEP
0.1% OF
STEP
0.1% OF
STEP
0.1% OF
STEP
0.1% OF
STEP
1
10
100
FREQUENCY (Hz)
10000
1000
–10 –8 –6 –4 –2
0
2
4
6
8
10
–10 –8 –6 –4 –2
0
2
4
6
8
10
OUTPUT STEP (V)
OUTPUT STEP (V)
1990 G24
1990 G22
1990 G23
0.1 to 10Hz Noise Voltage
Overshoot vs Capacitive Load
0.01 to 1Hz Noise Voltage
30
25
20
15
10
5
V
T
= ±1.5V TO ±15V
= 25°C
V
T
= ±1.5V TO ±15V
= 25°C
V
= ±50mV
S
A
G = 1
S
A
G = 1
OUT
GAIN = 1
= 10k
R
L
REF
REF
V
= 3V, 0V
S
V
= ±15V
S
0
1
2
3
4
5
6
7
8
9
10
0
10 20 30 40 50 60 70 80 90 100
10
100
1000
10000
CAPACITIVE LOAD (pF)
TIME (S)
TIME (S)
1990 G27
1990 G25
1990 G26
1990f
10
LT1990
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Large Signal Transient Response
Small Signal Transient Response
Small Signal Transient Response
GND
GND
1.5V
1990 G28
1990 G29
1990 G30
V
= ±15V
V
= 3V, 0V
50µs/DIV
50µs/DIV
V
= ±15V
S
50µs/DIV
S
S
G = 1, –1
G = 1, –1
G = 1, –1
R
V
= 10k
R
V
= 10k
R
V
= 10k
L
L
L
= GND
= 1.5V
= GND
REF
REF
REF
W
BLOCK DIAGRA
R5
900k
R7
10k
8
6
GAIN1
OUT
+
V
7
2
R1
R6
100k
1M
–IN
+IN
–
+
R2
1M
3
4
–
V
R8
900k
R10
10k
R3
40k
5
GAIN2
R4
40k
R9
100k
1
1990 SS
REF
U
U
U
PI FU CTIO S
REF (Pin 1): Reference Input. Sets the output level when GAIN2 (Pin 5): Gain = 10 Select Input. Configures the
the difference between the inputs is zero.
amplifierforagainof10whenconnectedtotheGAIN1pin.
The gain is equal to one when both GAIN2 and GAIN1 are
open. See Applications section for additional functions.
–IN (Pin 2): Inverting Input. Connects a 1MΩ resistor to
the op amp’s inverting input. Designed to permit high
voltage operation.
OUT (Pin 6): Output. VOUT = G • (V+IN – V–IN) + VREF, in the
basic configuration.
+IN (Pin 3): Noninverting Input. Connects a 1MΩ resistor
to the op amp’s noninverting input. Designed to permit V+ (Pin 7): Positive Power Supply. Can range from 2.7V to
high voltage operation.
36V above the V– voltage.
V– (Pin 4): Negative Power Supply. Can be either ground GAIN1 (Pin 8): Gain = 10 Select Input. Configures the
(in single supply applications) or a negative voltage (in amplifierforagainof10whenconnectedtotheGAIN2pin.
split supply applications).
The gain is equal to one when both GAIN1 and GAIN2 are
open. See Applications section for additional functions.
1990f
11
LT1990
U
W
U U
APPLICATIO S I FOR ATIO
Primary Features
For G = 10 where GAIN1 and GAIN2 are tied to a common
potential VGAIN
:
The LT1990 is a complete gain-block solution for high
inputcommonmodevoltageapplications, incorporatinga
low power precision operational amplifier providing rail-
to-rail output swing along with on-chip precision thin-film
resistors for high accuracy. The Block Diagram shows the
internal architecture of the part. The on-chip resistors
form a modified difference amplifier including a reference
port for introducing offset or other additive waveforms.
With pin-strapping alone either unity gain or gain of 10 is
produced with high precision. The resistor network is
designed to produce internal common-mode voltage divi-
sion of 27 so that a very large input range is available
compared to the power supply voltage(s) used by the
LT1990 itself. The LT1990 is ideally suited to situations
where relatively small signals need to be extracted from
high voltage circuits, as is the case in many current
monitoringinstrumentationapplicationsforexample.With
the ability to accept a range of input voltages well outside
the limits of the local power rails and its greater than 1MΩ
input impedances, development of precision low power
over-the-top and under-the-bottom instrumentation de-
signs is greatly simplified with the LT1990 single chip
solution over conventional discrete implementations.
V
V
CM+ ≤ 27 • V+ – 26 • VREF – 23 – VGAIN
CM– ≥ 27 • V– – 26 • VREF + 27 – VGAIN
Forsplitsuppliesoverabout±11V,thefull±250Vcommon
mode range is normally available (with VREF a small
fraction of the supply). With lower supply voltages, an
appropriate selection of VREF can tailor the input common
mode range to a specific requirement. As an example, the
following low supply voltage scenarios are readily imple-
mented with the LT1990:
Supply
+3V
V
REF
V
Range
CM
1.25V
1.25V
4.00V
–5V to 25V (e.g. 12V automotive environment)
–5V to 80V (e.g. 42V automotive environment)
+5V
+5V
–77V to 8V (e.g. telecom environment;
use downward signaling)
Configuring Other Gains
An intermediate gain G ranging between 1 and 10 may be
produced by placing an adjustable resistance between the
GAIN1 and GAIN2 pins according to the following nominal
relationship:
RGAIN ≈ (180k/(G – 1)) – 20k
Classic Difference Amplifier
While the expression is exact, the value is approximate
because the absolute resistance of the internal network
could vary on a unit-to-unit basis by as much as ±30%
from the nominal figures and the external gain resistance
is required to accommodate that deviation. Once ad-
justed, however, the gain stability is excellent by virtue of
the –30ppm/°C typical temperature coefficient offered by
the on-chip thin-film resistor process.
Used in the basic difference amplifier topology where the
gain G is pin-strap configurable to be unity or ten, the
following relationship is realized:
VO = G • (V+IN – V–IN) + VREF
To operate in unity gain, the GAIN1 and GAIN2 pins are left
disconnected. For G = 10 operation, the GAIN1 and GAIN2
pins are simply connected together or tied to a common
potential such as ground or V–.
Preserving and Enhancing Common Mode Rejection
The input common mode range capability is up to ±250V,
governed by the following relationships:
The basic difference amplifier topology of the LT1990
requires that source impedances seen by the input pins
+IN and –IN, should be matched to within a few tens of
ohms to avoid increasing common mode induced errors
beyond the basic production limits of the part. Known
source imbalances beyond that level should be compen-
sated for by the addition of series resistance to the lower-
For G = 1 and G = 10 where GAIN1 and GAIN2 are only tied
together (not grounded,etc):
V
V
CM+ ≤ 27 • V+ – 26 • VREF – 23
CM– ≥ 27 • V– – 26 • VREF + 27
1990f
12
LT1990
W U U
APPLICATIO S I FOR ATIO
U
Dual Differential-Input Arithmetic Block
impedance source. Also the source impedance of a signal
connected to the REF pin must be on the order of a few
ohms or less to preserve the high accuracy of the LT1990.
The internal resistor network topology of the LT1990
allows the GAIN1 and GAIN2 pins to be used as another
differential input in addition to the normal +IN and –IN
port. This can be a very useful function for implementing
servo-loop differential error amplifiers, for example. In
this mode of operation, the output is governed by the
following relationship:
WhiletheLT1990comesfromthefactorywithanexcellent
CMRR, some precision applications with a large applied
common mode voltage may require a method to trim out
residual common mode error. This is easily accomplished
by adding series resistance to each input, +IN and –IN,
such that an adjustable resistance difference of ±1kΩ is
provided. This is most easily realized by adding a fixed
1kΩ in series with one of the inputs, and a 2kΩ trimmer in
series with the other as shown in Figure 1. The trim range
of this configuration is ±0.1% for the internal gain resistor
matching, so a much more finely resolved correction is
available using the LT1990 than is realizable with ordinary
discrete solutions. In applications where the input
common mode voltage is relatively constant and large
(perhaps at or beyond the supply range), this same
configuration can be treated as an offset adjustment.
VO = 10 • (V+IN – V–IN + VGAIN2 – VGAIN1) + VREF
Unlike the main inputs, the GAIN1 and GAIN2 pins are
clampedbysubstratediodes andESDstructures, thusthe
operatingvoltagerangeofthesepinsislimitedtoV– –0.2V
to V– + 36V. If the GAIN inputs are brought beyond the
operatinginputrange, caremustbetakentolimittheinput
currents to less than 10mA to prevent damage to the
device. Also, since the gain setting resistors associated
withtheGAIN1andGAIN2inputsareinthe10kΩarea, low
source impedances are particularly important to preserve
the precision of the LT1990.
Thisdualdifferentialinputmodeofoperationisusedinthe
circuit as shown in Figure 2.
1k
–
LT1990
2k
ThiscircuitisahighefficiencyH-bridgedriverthatisPWM
modulated to provide a controlled current to an electro-
magnet coil. Since the common mode voltage of the
current sense resistor RS varies with operating current
and the coil properties, a differential feedback is required.
In this application, it was desirable to allow the control
inputtoutilizethewidecommonmoderangeport(+INand
–IN) so that constraints on input referencing are elimi-
nated. The GAIN1 and GAIN2 pins always operate within
the supply range and both ports operate with a gain of 10
to develop the loop error. The LTC1923 provides the loop
integrator and PWM functions of the servo.
+
Figure 1. Optional CMRR Trim
1990f
13
LT1990
W U U
U
APPLICATIO S I FOR ATIO
10k
PLLLPF
R
C
T
330pF
+
82k
V
IN
R
SLEW
T
10nF
1µF
V
7
DD
100k
20k
V
DD
V
REF
V
SDSYNC
CNTRL
EAOUT
FB
V
REF
DD
3
2
5
8
+
–
G2
G1
100k
100k
6
LT1990
REF
PDRVB
NDRVB
10µF
10nF
MPA*
MPB**
MNA*
4
C3
22µF
L1
100k
L2
1
10µH
10µH
V
DD
–
V
IN
LTC1923
1µF
C2
22µF
C1
I
= (V + – V )/(10 • R )
IN IN
(i.e. ±1A FOR ±1V)
COIL
S
22µF
MNB**
AGND
PGND
NDRVA
PDRVA
1µF
SS
I
LIM
+
0.1
V
CS
SET
R
S
–
FAULT
CS
10k
10k
0.1
C1, C2, C3: TAIYO YUDEN JMK325BJ226MM-T (X7R)
L1, L2: SUMIDA CDRH6D2B-220NC
*MNA, MPA: SILICONIX Si9801
V
I
THRM
TEC
+
ELECTRO-
MAGNET
COIL
I
COIL
H/C
TEC
TEC
**MNB, MPB: SILICONIX Si9801
–
1990 F02
V
TEC
Figure 2. PWM-Based ±1A Electromagnet Current Controller
1990f
14
LT1990
U
PACKAGE DESCRIPTIO
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.189 – .197
(4.801 – 5.004)
.045
±.005
NOTE 3
.050 BSC
7
5
8
6
.245
MIN
.160
±
.005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
.030
±
.005
TYP
1
3
4
2
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
(0.254 – 0.508)
× 45°
.053 – .069
(1.346 – 1.752)
.004 – .010
(0.101 – 0.254)
.008 – .010
(0.203 – 0.254)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
.050
(1.270)
BSC
.014 – .019
(0.355 – 0.483)
TYP
NOTE:
INCHES
1. DIMENSIONS IN
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
SO8 0303
1990f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
15
LT1990
U
TYPICAL APPLICATIO
Telecom Supply Current Monitor
Selectable Gain Amplifier
5V
+V
+
7
3
2
LOAD
I
L
+
–
48V
+
–
V
V
G2
G1
IN
IN
5
8
6
7
V
LT1990
4
–
3
2
OUT
G2
G1
+
–
5
8
6
R
S
V
LT1990
OUT
1
–V
REF
4
V
REF
1
–77V ≤ V ≤ 8V
CM
= V
REF
2N7002
REF
V
OUT
– (10 • I • R )
V
REF
= 4V
L
S
4
5
OUT
LT6650
IN
1nF
GAIN_SEL
(HI = 10X, LO = 1X)
174k
2N7002
1
GND FB
2
20k
1990 AI02
1990 AI01
1µF
Boosted Bidirectional Controlled Current Source
Bidirectional Controlled Current Source
+V
+V
7
3
2
+
–
V
CTL
1k
6
LT1990
4
CZT751
R
7
SENSE
3
2
+
–
V
CTL
1
–V
6
REF
I
LOAD
LT1990
+
I
V
/R
≤ 5mA
=100Ω,
LOAD = CTL SENSE
10µF
4
EXAMPLE: FOR R
SENSE
R
SENSE
1
OUTPUT IS 1mA PER 100mV INPUT
1990 AI03
REF
I
LOAD
1k
CZT651
–V
I
V
/R
≤ 100mA
SENSE
LOAD = CTL SENSE
EXAMPLE: FOR R
=10Ω,
1990 AI04
OUTPUT IS 1mA PER 10mV INPUT
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1787
Precision High Side Current Sense Amplifier
Micropower Instrumentation Amplifier
Dual –48V Supply and Fuse Monitor
On-Chip Precision Resistor Array
Micropower, Precision, G = 1 to 1000
Withstands ±200V Transients
LT1789
LTC1921
LT1991
High Accuracy Difference Amplifier
Micropower, Precision, Pin Selectable G = –13 to 14
Pin Selectable G = –7 to 8
LT1995
30MHz, 1000V/µs Gain Selectable Amplifier
Single Supply Programmable Gain Amplifier
LT6910
Digitally Controlled, SOT-23, G = 0 to 100
1990f
LT/TP 0704 1K • PRINTED IN USA
16
© LINEAR TECHNOLOGY CORPORATION 2004
相关型号:
LT1990ACS8#PBF
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: 0°C to 70°C
Linear
LT1990ACS8#TR
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: 0°C to 70°C
Linear
LT1990AHS8
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: -40°C to 125°C
Linear
LT1990AHS8#PBF
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: -40°C to 125°C
Linear
LT1990AHS8#TR
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: -40°C to 125°C
Linear
LT1990AHS8#TRPBF
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: -40°C to 125°C
Linear
LT1990AIS8#TR
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: -40°C to 85°C
Linear
LT1990AIS8#TRPBF
LT1990 - ±250V Input Range G = 1, 10, Micropower, Difference Amplifier; Package: SO; Pins: 8; Temperature Range: -40°C to 85°C
Linear
©2020 ICPDF网 联系我们和版权申明