matching specifications over the entire temperature
range.
All four resistors can be accessed and biased independently,
making the LT5400 a convenient and versatile choice for
any application that can benefit from matched resistors.
These resistor networks provide precise ratiometric stability
required in highly accurate difference amplifiers, voltage
references and bridge circuits.
The LT5400 is available in a space-saving 8-pin MSOP
package, and is specified over the temperature range of
–55°C to 150°C.
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
n
Excellent Matching
– A-Grade: 0.01% Matching
– B-Grade: 0.025% Matching
0.2ppm/°C Matching Temperature Drift
±75V Operating Voltage (±80V Abs Max)
8ppm/°C Absolute Resistor Value Temperature Drift
Long-Term Stability: <2ppm at 2000 Hrs
–55°C to 150°C Operating Temperature
8-Lead MSOP Package
APPLICATIONS
n
n
n
Difference Amplifier
Reference Divider
Precision Summing /Subtracting
TYPICAL APPLICATION
Difference Amplifier
30
LT5400
1
INPUTS
R1
R2
R3
R4
8
7
6
5
5400 TA01a
Distribution of Matching Drift
–
+
2
3
4
RELATIVE OCCURRENCE
–
+
25
20
15
10
5
0
REF
–1 –0.8–0.6–0.4–0.2 0 0.2 0.4 0.6 0.8 1
ppm/°C
5400 G01
5400f
1
LT5400
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
1
2
3
4
R1
R2
R3
R4
Total Voltage (Across Any 2 Pins) (Note 2).……….±80V
Power Dissipation (Each Resistor) (Note 3) ....... 800mW
Operating Temperature Range (Note 4)
LT5400C .............................................. –40°C to 85°C
LT5400I ............................................... –40°C to 85°C
LT5400H ............................................ –40°C to 125°C
LT5400MP ......................................... –55°C to 150°C
Specified Temperature Range (Note 4)
LT5400C .................................................. 0°C to 70°C
LT5400I ............................................... –40°C to 85°C
LT5400H ............................................ –40°C to 125°C
LT5400MP ......................................... –55°C to 150°C
Maximum Junction Temperature .......................... 150°C
Storage Temperature Range ................... –65°C to 150°C
8
7
6
5
MS8E PACKAGE
8-LEAD PLASTIC MSOP
θ
JA
= 40°C/W,
θ
JC
= 10°C/W
EXPOSED PAD (PIN 9) IS FLOATING
AVAILABLE OPTIONS
PART NUMBER
LT5400-1
LT5400-2
LT5400-3
R2 = R3 (Ω)
10k
100k
10k
R1 = R4 (Ω)
10k
100k
100k
RESISTOR RATIO
1:1
1:1
1:10
5400f
2
LT5400
ORDER INFORMATION
LEAD FREE FINISH
LT5400ACMS8E-1#PBF
LT5400BCMS8E-1#PBF
LT5400AIMS8E-1#PBF
LT5400BIMS8E-1#PBF
LT5400AHMS8E-1#PBF
LT5400BHMS8E-1#PBF
LT5400BMPMS8E-1#PBF
LT5400ACMS8E-2#PBF
LT5400BCMS8E-2#PBF
LT5400AIMS8E-2#PBF
LT5400BIMS8E-2#PBF
LT5400AHMS8E-2#PBF
LT5400BHMS8E-2#PBF
LT5400BMPMS8E-2#PBF
LT5400ACMS8E-3#PBF
LT5400BCMS8E-3#PBF
LT5400AIMS8E-3#PBF
LT5400BIMS8E-3#PBF
LT5400BHMS8E-3#PBF
TAPE AND REEL
LT5400ACMS8E-1#TRPBF
LT5400BCMS8E-1#TRPBF
LT5400AIMS8E-1#TRPBF
LT5400BIMS8E-1#TRPBF
LT5400AHMS8E-1#TRPBF
LT5400BHMS8E-1#TRPBF
LT5400BMPMS8E-1#TRPBF
LT5400ACMS8E-2#TRPBF
LT5400BCMS8E-2#TRPBF
LT5400AIMS8E-2#TRPBF
LT5400BIMS8E-2#TRPBF
LT5400AHMS8E-2#TRPBF
LT5400BHMS8E-2#TRPBF
LT5400BMPMS8E-2#TRPBF
LT5400ACMS8E-3#TRPBF
LT5400BCMS8E-3#TRPBF
LT5400AIMS8E-3#TRPBF
LT5400BIMS8E-3#TRPBF
LT5400BHMS8E-3#TRPBF
PART MARKING*
LTFVR
LTFVR
LTFVR
LTFVR
LTFVR
LTFVR
LTFVR
LTGBG
LTGBG
LTGBG
LTGBG
LTGBG
LTGBG
LTGBG
LTGBH
LTGBH
LTGBH
LTGBH
LTGBH
PACKAGE DESCRIPTION
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic MSOP
SPECIFIED TEMPERATURE RANGE
0°C to 70°C
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
–40°C to 125°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
–40°C to 125°C
–40°C to 125°C
–55°C to 150°C
0°C to 70°C
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
–40°C to 125°C
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/
5400f
3
LT5400
ELECTRICAL CHARACTERISTICS
SYMBOL
∆R/R
PARAMETER
Resistor Matching Ratio (Any Resistor to Any
Other Resistor)
The
l
denotes the specifications which apply over the full specified
temperature range, otherwise specifications are at T
A
= 25°C.
CONDITIONS
A-Grade
T
A
= 0°C to 70°C
T
A
= –40°C to 85°C
T
A
= –40°C to 125°C
B-Grade
A-Grade (Note 6)
B-Grade (Note 6)
(Note 5)
Mil-Std-202 Method 308
A-Grade
B-Grade
Distributed Capacitance
∆R/∆T
Absolute Resistor Value Temperature Drift
Resistor Matching Ratio Long-Term Drift
Resistor Matching Ratio Moisture Resistance
Resistor to Exposed Pad
Resistor to Resistor
(Note 5)
35°C 2000Hours
85°C 85%R.H. 168Hours
l
l
l
l
l
l
l
l
l
l
l
MIN
TYP
MAX
±0.010
±0.010
±0.0125
±0.0125
±0.025
±0.005
±0.015
UNITS
%
%
%
%
%
%
%
ppm/°C
ppm/V
dB
(∆R/R)
CMRR
Matching for CMRR
(∆R/R)/∆T
Resistor Matching Ratio Temperature Drift
Resistor Voltage Coefficient
Excess Current Noise
∆R
Absolute Resistor Tolerance
±0.2
<0.1
<–55
±1
±7.5
±15
5.5
1.4
–10
8
<2
<2
25
%
%
pF
pF
ppm/°C
ppm
ppm
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.
Note 2:
The instantaneous difference between the highest voltage applied
to any pin and the lowest voltage applied to any other pin should not
exceed the Absolute Maximum Rating. This includes the voltage across
any resistor, the voltage across any pin with respect to the exposed pad of
the package, and the voltage across any two unrelated pins.
Note 3:
In order to keep the junction temperature within the Absolute
Maximum Rating, maximum power dissipation should be derated at
elevated ambient temperatures.
Note 4:
The LT5400C is guaranteed functional over the operating
temperature range of –40°C to 85°C. The LT5400C 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 LT5400I
is guaranteed to meet specified performance from –40°C to 85°C. The
LT5400H is guaranteed to meet specified performance from –40°C to
125°C and is 100% tested at these temperature extremes. The LT5400MP
is guaranteed to meet specified performance from –55°C to 150°C and is
100% tested at these temperature extremes.
Note 5:
This parameter is not 100% tested.
Note 6:
(∆R/R)
CMRR
(Matching for CMRR) is a metric for the contribution
of error from the LT5400 when configured in a difference amplifier (see
Difference Amplifier in Typical Applications):
1
R3
R1
(
∆R/R
)
CMRR
=
2 •
R2 – R4
•
R2
R1
The resistor contribution to CMRR can then be calculated in the following
way:
R2
4•
R1
CMRR
=
(
∆R/R
)
•
CMRR
R2 R3
+
2
+
R1 R4
For LT5400 options with resistor ratio 1:1, the resistor contribution to
CMRR can be simplified:
CMRR ≈ (∆R/R)
CMRR
5400f
4
LT5400
TYPICAL PERFORMANCE CHARACTERISTICS
Distribution of Matching Drift
30
CHANGE IN RESISTOR MATCHING (ppm)
25
RELATIVE OCCURRENCE
20
15
10
5
0
5
4
3
2
1
0
–1
–2
–3
–4
–5
0
400
800
1200
TIME (HOURS)
1600
2000
5400 G02
Change in Matching vs Time
–1 –0.8–0.6–0.4–0.2 0 0.2 0.4 0.6 0.8 1
ppm/°C
5400 G01
APPLICATIONS INFORMATION
Where to Connect the Exposed Pad
The exposed pad is not DC connected to any resistor
terminal. Its main purpose is to reduce the internal tem-
perature rise when the application calls for large amounts
of dissipated power in the resistors. The exposed pad can
be tied to any voltage (such as ground) as long as the
absolute maximum ratings are observed.
There is capacitive coupling between the resistors and the
exposed pad, as specified in the Electrical Characteristics
table. To avoid interference, do not tie the exposed pad to
noisy signals or noisy grounds.
Connecting the exposed pad to a quiet AC ground is
recommended as it acts as an AC shield and reduces the
amount of resistor-resistor capacitance.
Thermal Considerations
Each resistor is rated for relatively high power dissipation,
as listed in the Absolute Maximum Ratings section of
this data sheet. To calculate the internal temperature rise
inside the package, add together the power dissipated in
all of the resistors, and multiply by the thermal resistance
coefficient of the package (θ
JA
or
θ
JC
as applicable).
For example, if each resistor dissipates 250mW, for a total
of 1W, the total temperature rise inside the package equals
40°C. All 4 resistors will be at the same temperature,
regardless of which resistor dissipates more power. The
junction temperature must be kept within the Absolute
Maximum Rating. At elevated ambient temperatures, this
places a limit on the maximum power dissipation.
In addition to limiting the maximum power dissipation,
the maximum voltage across any two pins must also be
kept less than the absolute maximum rating.
ESD
The LT5400 can withstand up to ±1kV of electrostatic
discharge (ESD, human body). To achieve the highest
precision matching, the LT5400 is designed without explicit
ESD internal protection diodes. ESD beyond this voltage
can damage or degrade the device including causing
pin-to-pin shorts.
To protect the LT5400 against large ESD strikes, external
protection can be added using diodes to the circuit supply
rails or bidirectional Zeners to ground (Figure 1).
