LT1787/LT1787HV
Precision, High Side
Current Sense Amplifiers
FEATURES
■
■
■
■
■
■
■
■
■
■
DESCRIPTIO
Input Offset Voltage: 75
µ
V (Max)
60V Supply Operation (LT1787HV)
12-Bit Dynamic Range
Operating Current: 60µA
User-Selectable External Sense Resistor
Bidirectional High Side Current Sensing
Unidirectional or Bidirectional Output
Input Noise Filtering
–40°C to 125°C Operating Temperature Range
Available in 8-Lead SO and MSOP Packages
APPLICATIO S
■
■
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Battery Monitoring
Power Monitoring
Portable Phones
Cellular Phones
Portable Test/Measurement Systems
Battery-Operated Systems
The LT
®
1787 is a complete micropower precision high
side current sense amplifier. The LT1787 monitors bidi-
rectional currents via the voltage across an external sense
resistor. A current or voltage output indicates the direction
and magnitude of the sense current. The LT1787 delivers
greater than a 12-bit dynamic range with ultralow 40µV
input offset voltage compared to a typical 250mV full-
scale input voltage. A fixed gain of 8 is set by onboard
precision resistors. Input signal filtering is easily imple-
mented with a capacitor between the FIL
–
and FIL
+
pins.
The LT1787HV operates from 2.5V to 60V total supply
voltage and the LT1787 operates from 2.5V to 36V total
supply voltage. Both versions have a PSRR in excess of
120dB. The LT1787/LT1787HV draw only 60µA and are
available in 8-lead SO and MSOP packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
12-Bit Dynamic Resolution Unidirectional Output into LTC
®
1286 ADC
TO
LOAD
I = 100A
1
FIL
–
LT1787HV
R
SENSE
0.0016Ω
FIL
+
8
2.5V TO 60V
INPUT OFFSET VOLTAGE (µV)
50
40
30
20
10
0
–10
–20
–30
–40
–50
0
10
30
40
50
20
TOTAL SUPPLY VOLTAGE (V)
60
–
2 V
S
V
S+
7
3
4
DNC
V
EE
V
BIAS
6
R
OUT
20k
V
OUT
C2
0.1µF
5
R1
15k
C1
1µF
V
REF
V
CC
CS
+IN
LTC1286 CLK
–IN
D
GND
OUT
5V
TO
µP
V
OUT
= V
BIAS
+ (8 • I
LOAD
• R
SENSE
)
LT1634-1.25
1787 TA01
U
Input Offset Voltage vs Supply Voltage
1787 TA01b
U
U
1787fc
1
LT1787/LT1787HV
ABSOLUTE
MAXIMUM
RATINGS
Differential Sense Voltage ......................................
±10V
Total Supply Voltage (LT1787) ................................ 40V
Total Supply Voltage (LT1787HV) ........................... 65V
Output Voltage ..................... (V
EE
– 0.3V) to (V
EE
+ 35V)
Output Bias Voltage ............. (V
EE
– 0.3V) to (V
EE
+ 35V)
Operating Temperature Range (Note 3)
LT1787C ............................................. – 40°C to 85°C
LT1787I .............................................. – 40°C to 85°C
LT1787H .......................................... – 40°C to 125°C
PACKAGE/ORDER INFORMATION
TOP VIEW
TOP VIEW
FIL
–
1
V
S–
2
DNC*
3
V
EE
4
FIL
+
V
S+
V
BIAS
V
OUT
8
7
6
5
MS8 PACKAGE
8-LEAD PLASTIC MSOP
* DO NOT CONNECT
T
JMAX
= 150°C,
θ
JA
= 250°C/ W
ORDER PART NUMBER
LT1787CMS8
LT1787IMS8
LT1787HVCMS8
LT1787HVIMS8
MS8 PART MARKING
LTGM
LTGN
LTKJ
LTKK
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.
(Note 5)
The
●
denotes the specifications which apply over the temperature range 0°C
≤
T
A
≤
70°C, otherwise specifications are at T
A
= 25°C.
Total supply = (V
S–
– V
EE
) = 2.5V to 36V (LT1787C), 2.5V to 60V (LT1787HVC) unless otherwise specified.
SYMBOL
V
S –
, V
S +
V
SENSE
V
OS
PARAMETER
CONDITIONS
●
●
●
●
●
●
ELECTRICAL CHARACTERISTICS
Sense Amplifier Supply Voltage Single Supply Operation (LT1787)
Single Supply Operation (LT1787HV)
Input Sense Voltage Full Scale
Input Offset Voltage (S8)
V
SENSE
= V
S+
– V
S–
, V
S
= 10V, V
BIAS
= 5V, A
V
= 8
±10%
I
OUT
= 0, V
S
Supply = 5V
0°C
≤
T
A
≤
70°C
I
OUT
= 0 (LT1787)
0°C
≤
T
A
≤
70°C
I
OUT
= 0 (LT1787HV)
0°C
≤
T
A
≤
70°C
2
U
U
W
W W
U
W
(Notes 1, 2)
Specified Temperature Range (Note 4)
LT1787C ............................................. – 40°C to 85°C
LT1787I .............................................. – 40°C to 85°C
LT1787H .......................................... – 40°C to 125°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
FIL
–
1
V
S–
2
DNC*
3
V
EE
4
8
7
6
5
FIL
+
V
S+
V
BIAS
V
OUT
S8 PACKAGE
8-LEAD PLASTIC SO
* DO NOT CONNECT
T
JMAX
= 150°C,
θ
JA
= 190°C/ W
ORDER PART NUMBER
LT1787CS8
LT1787IS8
LT1787HS8
LT1787HVCS8
LT1787HVIS8
LT1787HVHS8
S8 PART MARKING
1787
1787I
1787H
1787HV
787HVI
787HVH
MIN
2.5
2.5
500
– 75
– 135
– 100
– 160
– 100
– 160
TYP
MAX
36
60
UNITS
V
V
mV
µV
µV
µV
µV
µV
µV
1787fc
±40
75
135
100
160
100
160
LT1787/LT1787HV
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
Input Offset Voltage (MS8)
(Note 5)
The
●
denotes the specifications which apply over the temperature range 0°C
≤
T
A
≤
70°C, otherwise specifications are at T
A
= 25°C.
Total supply = (V
S –
– V
EE
) = 2.5V to 36V (LT1787C), 2.5V to 60V (LT1787HVC) unless otherwise specified.
CONDITIONS
I
OUT
= 0, V
S
Supply = 5V
0°C
≤
T
A
≤
70°C
I
OUT
= 0 (LT1787)
0°C
≤
T
A
≤
70°C
I
OUT
= 0 (LT1787HV)
0°C
≤
T
A
≤
70°C
MIN
– 125
– 230
– 150
– 250
– 150
– 250
0.5
4
●
●
TYP
±40
●
●
●
●
MAX
125
230
150
250
150
250
2
600
1080
1000
1840
UNITS
µV
µV
µV
µV
µV
µV
µV/°C
nA
µV
µV
µV
µV
µA/V
V
OS
TC
I
OUT(O)
V
OUT(O)
Temperature Coefficient of V
OS
No-Load Output Current Error
No-Load Output Voltage Error
(S8)
No-Load Output Voltage Error
(MS8)
V
S
Supply = 5V (Note 6)
V
SENSE
= 0V
V
SENSE
= 0V, V
S
Supply = 5V
0°C
≤
T
A
≤
70°C
V
SENSE
= 0V, V
S
Supply = 5V
0°C
≤
T
A
≤
70°C
±V
SENSE
= 10mV, 50mV, 100mV, 150mV, 250mV,
V
S
Supply = Total Supply + |V
SENSE
|
±V
SENSE
= 100mV, V
S
Supply = 5V
±V
SENSE
= 100mV, V
S
Supply = 5V
V
SENSE
= 0V, V
S
Supply = 2.5V to 36V (LT1787)
V
SENSE
= 0V, V
S
Supply = 2.5V to 60V (LT1787HV)
–600
– 1080
– 1000
– 1840
400
g
m
A
V
V
S
PSRR
Tranconductance, I
OUT
/ V
SENSE
Gain, V
OUT
/ V
SENSE
Output Voltage Gain Error
V
S
Supply Rejection Ratio
●
●
●
●
●
●
7.76
–3
120
120
100
100
100
100
8
1
135
135
130
130
130
130
10
50
60
±50
V
BIAS
±1.024
8.24
3
V/V
%
dB
dB
dB
dB
dB
dB
V
EE
PSRR Negative Supply Rejection Ratio V
SENSE
= 0V, V
S
Supply = 15V, V
BIAS
= 0V,
V
EE
= – 1V to – 15V (LT1787)
V
SENSE
= 0V, V
S
Supply = 40V, V
BIAS
= 0V,
V
EE
= – 1V to – 15V (LT1787HV)
∆V
OS
∆V
BIAS
I
S+(O)
I
S–(O)
I
EE(O)
I
OUT
V
OUT
V
OMIN
Change in Input Offset Voltage
with Change in V
BIAS
Voltage
Positive Input Sense Current
Negative Input Sense Current
Negative Supply Current
Output Current
Output Voltage
Ripple Rejection
Minimum Output Voltage
V
SENSE
= 0V, V
S
Supply = 36V, V
BIAS
= 0.5V to 25V (LT1787)
●
V
SENSE
= 0V, V
S
Supply = 60V, V
BIAS
= 0.5V to 25V (LT1787HV)
●
V
SENSE
= 0V
V
SENSE
= 0V
V
SENSE
= 0V
V
SENSE
=
±128mV
V
SENSE
=
±128mV,
V
S
+
≥
3.3V
●
●
●
20
100
120
µA
µA
µA
µA
V
dB
V
S+
= V
S–
= 20V,
∆V
S
Supply = 1V, f = 1kHz
V
SENSE
= 0V, V
BIAS
= 0V
V
SENSE
= V
S+
– V
S–
= –128mV, V
BIAS
= 0V
V
SENSE
= 0V, V
BIAS
= 0V
V
SENSE
= V
S+
– V
S–
= –128mV, V
BIAS
= 0V
●
80
88
30
10
45
49
50
55
60
65
54
59
64
69
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
V
kΩ
kΩ
●
30
10
32
38
43
49
Unipolar Output
Saturation Voltage
V
SENSE
= 2mV, V
BIAS
= 0V
V
SENSE
= 4mV, V
BIAS
= 0V
V
SENSE
= 5mV, V
BIAS
= 0V
V
SENSE
= 6mV, V
BIAS
= 0V
V
SENSE
= 2mV, V
BIAS
= 0V
V
SENSE
= 4mV, V
BIAS
= 0V
V
SENSE
= 5mV, V
BIAS
= 0V
V
SENSE
= 6mV, V
BIAS
= 0V
●
●
●
●
32
38
43
49
V
S +
– 0.75
1.25
20
V
OMAX
R
OUT
Maximum Output Voltage
Pin 1 to Pin 2, Pin 7 to Pin 8
Pin 5 to Pin 6
Output Resistor
R
G1A,
R
G2A
Input Gain-Setting Resistor
1787fc
3
LT1787/LT1787HV
ELECTRICAL CHARACTERISTICS
SYMBOL
V
S –
, V
S +
V
SENSE
V
OS
PARAMETER
CONDITIONS
●
●
●
●
●
●
●
●
●
●
The
●
denotes the specifications which apply over the temperature range –40°C
≤
T
A
≤
85°C, otherwise specifications are at
T
A
= 25°C. Total supply = (V
S–
– V
EE
) = 2.5V to 36V (LT1787I), 2.5V to 60V (LT1787HVI) unless otherwise specified. (Note 5)
MIN
2.5
2.5
500
– 75
– 200
– 100
– 225
– 100
– 225
– 125
– 250
– 150
– 280
– 150
– 280
0.5
4
●
●
TYP
MAX
36
60
UNITS
V
V
mV
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV/°C
nA
µV
µV
µV
µV
µA/V
Sense Amplifier Supply Voltage Single Supply Operation (LT1787)
Single Supply Operation (LT1787HV)
Input Sense Voltage Full Scale
Input Offset Voltage (S8)
V
SENSE
= V
S+
– V
S–
, V
S
= 10V, V
BIAS
= 5V, A
V
= 8
±10%
I
OUT
= 0, V
S
Supply = 5V
– 40°C
≤
T
A
≤
85°C
I
OUT
= 0 (LT1787)
– 40°C
≤
T
A
≤
85°C
I
OUT
= 0 (LT1787HV)
– 40°C
≤
T
A
≤
85°C
Input Offset Voltage (MS8)
I
OUT
= 0, V
S
Supply = 5V
– 40°C
≤
T
A
≤
85°C
I
OUT
= 0 (LT1787)
– 40°C
≤
T
A
≤
85°C
I
OUT
= 0 (LT1787HV)
– 40°C
≤
T
A
≤
85°C
±40
75
200
100
225
100
225
±40
125
250
150
280
150
280
2
600
1600
1000
2000
V
OS
TC
I
OUT(O)
V
OUT(O)
Temperature Coefficient of V
OS
No-Load Output Current Error
No-Load Output Voltage Error
(S8)
No-Load Output Voltage Error
(MS8)
V
S
Supply = 5V (Note 6)
V
SENSE
= 0V
V
SENSE
= 0V, V
S
Supply = 5V
– 40°C
≤
T
A
≤
85°C
V
SENSE
= 0V, V
S
Supply = 5V
– 40°C
≤
T
A
≤
85°C
±V
SENSE
= 10mV, 50mV, 100mV, 150mV, 250mV,
V
S
Supply = Total Supply + |V
SENSE
|
±V
SENSE
= 100mV, V
S
Supply = 5V
±V
SENSE
= 100mV, V
S
Supply = 5V
V
SENSE
= 0V, V
S
Supply = 2.5V to 36V (LT1787)
V
SENSE
= 0V, V
S
Supply = 2.5V to 60V (LT1787HV)
–600
– 1600
– 1000
– 2000
400
g
m
A
V
V
S
PSRR
Tranconductance, I
OUT
/ V
SENSE
Gain, V
OUT
/ V
SENSE
Output Voltage Gain Error
V
S
Supply Rejection Ratio
●
●
●
●
●
●
7.76
–3
120
120
100
100
100
100
8
1
135
135
130
130
130
130
10
50
60
±50
V
BIAS
±1.024
8.24
3
V/V
%
dB
dB
dB
dB
dB
dB
V
EE
PSRR Negative Supply Rejection Ratio V
SENSE
= 0V, V
S
Supply = 15V, V
BIAS
= 0V,
V
EE
= – 1V to – 15V (LT1787)
V
SENSE
= 0V, V
S
Supply = 40V, V
BIAS
= 0V,
V
EE
= – 1V to – 15V (LT1787HV)
∆V
OS
∆V
BIAS
I
S+(O)
I
S–(O)
I
EE(O)
I
OUT
V
OUT
V
OMIN
Change in Input Offset Voltage
with Change in V
BIAS
Voltage
Positive Input Sense Current
Negative Input Sense Current
Negative Supply Current
Output Current
Output Voltage
Ripple Rejection
Minimum Output Voltage
V
SENSE
= 0V, V
S
Supply = 36V, V
BIAS
= 0.5V to 25V (LT1787)
●
V
SENSE
= 0V, V
S
Supply = 60V, V
BIAS
= 0.5V to 25V (LT1787HV)
●
V
SENSE
= 0V
V
SENSE
= 0V
V
SENSE
= 0V
V
SENSE
=
±128mV
V
SENSE
=
±128mV,
V
S+
≥
3.3V
V
S+
= V
S–
= 20V,
∆V
S
Supply = 1V, f = 1kHz
V
SENSE
= 0V, V
BIAS
= 0V
V
SENSE
= V
S+
– V
S–
= –128mV, V
BIAS
= 0V
V
SENSE
= 0V, V
BIAS
= 0V
V
SENSE
= V
S+
– V
S–
= –128mV, V
BIAS
= 0V
●
●
●
●
●
20
100
120
µA
µA
µA
µA
V
dB
80
88
30
10
30
10
45
51
mV
mV
mV
mV
1787fc
4
LT1787/LT1787HV
The
●
denotes the specifications which apply over the temperature range –40°C
≤
T
A
≤
85°C, otherwise specifications are at
T
A
= 25°C. Total supply = (V
S–
– V
EE
) = 2.5V to 36V (LT1787I), 2.5V to 60V (LT1787HVI) unless otherwise specified. (Note 5)
SYMBOL
PARAMETER
Unipolar Output
Saturation Voltage
CONDITIONS
V
SENSE
= 2mV, V
BIAS
= 0V
V
SENSE
= 4mV, V
BIAS
= 0V
V
SENSE
= 5mV, V
BIAS
= 0V
V
SENSE
= 6mV, V
BIAS
= 0V
V
SENSE
= 2mV, V
BIAS
= 0V
V
SENSE
= 4mV, V
BIAS
= 0V
V
SENSE
= 5mV, V
BIAS
= 0V
V
SENSE
= 6mV, V
BIAS
= 0V
V
OMAX
R
OUT
Maximum Output Voltage
Pin 1 to Pin 2, Pin 7 to Pin 8
Pin 5 to Pin 6
Output Resistor
R
G1A,
R
G2A
Input Gain-Setting Resistor
●
●
●
●
ELECTRICAL CHARACTERISTICS
MIN
TYP
32
38
43
49
32
38
43
49
V
S +
– 0.75
1.25
20
MAX
50
55
60
65
56
61
66
71
UNITS
mV
mV
mV
mV
mV
mV
mV
mV
V
kΩ
kΩ
The
●
denotes the specifications which apply over the temperature range –40°C
≤
T
A
≤
125°C, otherwise specifications are at
T
A
= 25°C. Total supply = (V
S–
– V
EE
) = 2.5V to 36V (LT1787H), 2.5V to 60V (LT1787HVH) unless otherwise specified. (Note 5)
V
S –
, V
S +
V
SENSE
V
OS
Sense Amplifier Supply Voltage Single Supply Operation (LT1787H)
Single Supply Operation (LT1787HVH)
Input Sense Voltage Full Scale
Input Offset Voltage
V
SENSE
= V
S+
– V
S–
, V
S
= 10V, V
BIAS
= 5V, A
V
= 8
±10%
I
OUT
= 0, V
S
Supply = 5V
– 40°C
≤
T
A
≤
125°C
I
OUT
= 0 (LT1787H)
– 40°C
≤
T
A
≤
125°C
I
OUT
= 0 (LT1787HVH)
– 40°C
≤
T
A
≤
125°C
V
OS
TC
I
OUT(O)
V
OUT(O)
g
m
A
V
V
S
PSRR
Temperature Coefficient of V
OS
No-Load Output Current Error
No-Load Output Voltage Error
Tranconductance, I
OUT
/ V
SENSE
Gain, V
OUT
/ V
SENSE
Output Voltage Gain Error
V
S
Supply Rejection Ratio
V
S
Supply = 5V (Note 6)
V
SENSE
= 0V
V
SENSE
= 0V, V
S
Supply = 5V
– 40°C
≤
T
A
≤
125°C
±V
SENSE
= 10mV, 50mV, 100mV, 150mV, 250mV,
V
S
Supply = Total Supply + |V
SENSE
|
±V
SENSE
= 100mV, V
S
Supply = 5V
±V
SENSE
= 100mV, V
S
Supply = 5V
V
SENSE
= 0V, V
S
Supply = 2.5V to 36V (LT1787H)
V
SENSE
= 0V, V
S
Supply = 2.5V to 60V (LT1787HVH)
●
●
●
●
●
●
●
●
●
●
●
●
●
●
2.5
2.5
500
– 75
– 400
– 100
– 550
– 100
– 550
0.5
4
–600
– 3200
400
7.76
–3
100
100
100
100
100
100
8
1
130
130
130
130
130
130
10
50
60
±50
V
BIAS
±1.024
±40
36
60
75
400
100
550
100
550
4
600
3200
V
V
mV
µV
µV
µV
µV
µV
µV
µV/°C
nA
µV
µV
µA/V
8.24
3
V/V
%
dB
dB
dB
dB
dB
dB
V
EE
PSRR Negative Supply Rejection Ratio V
SENSE
= 0V, V
S
Supply = 15V, V
BIAS
= 0V,
V
EE
= – 1V to – 15V (LT1787H)
V
SENSE
= 0V, V
S
Supply = 40V, V
BIAS
= 0V,
V
EE
= – 1V to – 15V (LT1787HVH)
∆V
OS
∆V
BIAS
I
S+(O)
I
S–(O)
I
EE(O)
I
OUT
V
OUT
Change in Input Offset Voltage
with Change in V
BIAS
Voltage
Positive Input Sense Current
Negative Input Sense Current
Negative Supply Current
Output Current
Output Voltage
Ripple Rejection
V
SENSE
= 0V, V
S
Supply = 36V, V
BIAS
= 0.5V to 25V (LT1787H)
●
V
SENSE
= 0V, V
S
Supply = 60V, V
BIAS
= 0.5V to 25V (LT1787HVH)
●
V
SENSE
= 0V
V
SENSE
= 0V
V
SENSE
= 0V
V
SENSE
=
±128mV
V
SENSE
=
±128mV,
V
S+
≥
3.3V
V
S+
= V
S–
= 20V,
∆V
S
Supply = 1V, f = 1kHz
●
●
●
●
25
115
140
µA
µA
µA
µA
V
dB
1787fc
80
88
5
嵌入式系统
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