LTC6078/LTC6079
Micropower Precision,
Dual/Quad CMOS
Rail-to-Rail Input/Output Amplifiers
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DESCRIPTIO
FEATURES
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Maximum Offset Voltage of 25µV (25°C)
Maximum Offset Drift of 0.7µV/°C
Maximum Input Bias:
1pA (25°C)
50pA (≤85°C)
Micropower: 54µA per Amp
95dB CMRR (Min)
100dB PSRR (Min)
Input Noise Voltage Density: 16nV/√Hz
Rail-to-Rail Inputs and Outputs
2.7V to 5.5V Operation Voltage
LTC6078 Available in 8-Lead MSOP and 10-Lead DFN
Packages; LTC6079 Available in 16-Lead SSOP and
DFN Packages
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APPLICATIO S
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Photodiode Amplifier
High Impedance Sensor Amplifier
Microvolt Accuracy Threshold Detection
Instrumentation Amplifiers
Battery Powered Applications
Input offset voltage is trimmed to less than 25µV and the
CMOS inputs draw less than 50pA of bias current. The low
offset drift, excellent CMRR, and high voltage gain make
it a good choice for precision signal conditioning.
Each amplifier draws only 54µA current on a 3V supply. The
micropower, rail-to-rail operation of the LTC6078/LTC6079
is well suited for portable instruments and single supply
applications.
The LTC6078/LTC6079 are specified on power supply
voltages of 3V and 5V from –40 to 125°C. The dual amplifier LTC6078 is available in 8-lead MSOP and 10-lead
DFN packages. The quad amplifier LTC6079 is available
in 16-lead SSOP and DFN packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Patent Pending.
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The LTC®6078/LTC6079 are dual/quad, low offset, low
noise operational amplifiers with low power consumption
and rail-to-rail input/output swing.
TYPICAL APPLICATIO
Thermocouple Signal Conditioner
VOS Distribution
14
5V
SMT
1/4W
150k
+
1/2
LTC6078
0.1µF
OMEGA
5TC-TT-K-30-36
THERMOCOUPLE
SMT
1/4W
150k
–
5V
2.49M
K
LT1025
OUT = 10mV/°C
0°C TO 500°C ±0.5°C
1k
40.6µV/°C
100pF
10k
5.6pF
AMPLIFIER PROTECTED TO ±190V, ACCIDENTAL CONTACT
60789 TA01a
NUMBER OF AMPS OUT OF 200
NORMALLY
FLOATING
LTC6078MS8
VS = 3V
12 VCM = 0.5V
TA = 25°C
10
8
6
4
2
0
–11 –9 –7 –5 –3 –1 1
VOS (µV)
3
5
7
9
60789 TA01b
60789fa
1
LTC6078/LTC6079
W W
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W
ABSOLUTE
AXI U RATI GS
(Note 1)
Total Supply Voltage (V+ to V–) ...................................6V
Input Voltage...................................................... V– to V+
Output Short Circuit Duration (Note 2) ............ Indefinite
Operating Temperature Range (Note 3)
LTC6078C, LTC6079C .......................... –40°C to 85°C
LTC6078I, LTC6079I ............................ –40°C to 85°C
LTC6078H, LTC6079H........................ –40°C to 125°C
(Not Available in DFN Package)
Specified Temperature Range (Note 4)
LTC6078C, LTC6079C .............................. 0°C to 70°C
LTC6078I, LTC6079I ............................ –40°C to 85°C
LTC6078H, LTC6079H........................ –40°C to 125°C
Junction Temperature
DFN Packages ................................................... 125°C
All Other Packages ............................................ 150°C
Storage Temperature Range
DFN Packages .................................... –65°C to 125°C
All Other Packages ............................. –65°C to 150°C
Lead Temperature (Soldering, 10 Sec) .................. 300°C
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W
U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
10 V +
OUTA
1
–INA
2
+INA
3
V–
4
7 +INB
SHDN_A
5
6 SHDN_B
9 OUTB
A
B
8 –INB
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 43°C/W
UNDERSIDE METAL CONNECTED TO V–
TOP VIEW
OUTA
–INA
+INA
V–
1
2
3
4
1
–INA
2
+INA
3
TOP VIEW
16 OUTD
A
D
15 –IND
14 +IND
+
4
13 V
+INB
5
12 +INC
–INB
6
11 –INC
OUTB
7
10 OUTC
NC
8
9
V
B
C
B
V+
OUTB
–INB
+INB
MS8 PACKAGE
8-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 200°C/W
TOP VIEW
OUTA
A
8
7
6
5
–
NC
DHC PACKAGE
16-LEAD (5mm × 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 43°C/W
UNDERSIDE METAL CONNECTED TO V–
OUTA
1
–INA
2
+INA
3
14 +IND
V+
4
13 V –
+INB
5
16 OUTD
A
B
D
C
15 –IND
12 +INC
–INB
6
11 –INC
OUTB
7
10 OUTC
NC
8
9
NC
GN PACKAGE
16-LEAD PLASTIC SSOP
TJMAX = 150°C, θJA = 110°C/W
ORDER PART
NUMBER
DD PART
MARKING*
LTC6078CDD
LTC6078IDD
LBBB
LBBB
ORDER PART
NUMBER
MS8 PART
MARKING*
LTC6078ACMS8
LTC6078CMS8
LTC6078AIMS8
LTC6078IMS8
LTC6078AHMS8
LTC6078HMS8
LTAJZ
LTAJZ
LTAJZ
LTAJZ
LTAJZ
LTAJZ
ORDER PART
NUMBER
DHC PART
MARKING*
LTC6079CDHC
LTC6079IDHC
6079
6079
ORDER PART
NUMBER
GN PART
MARKING
LTC6079CGN
LTC6079IGN
LTC6079HGN
6079
6079I
6079H
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.
*The temperature grades and parametric grades are identified by a label on the shipping container.
60789fa
2
LTC6078/LTC6079
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 3V, V– = 0V, VCM = 0.5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
C, I SUFFIXES
MIN
VOS
Offset Voltage (Note 5)
ΔVOS ⁄ΔT Input Offset Voltage Drift
(Note 5)
LTC6078MS8, LTC6078AMS8, LTC6079GN
VCM = 0.5V, 2.5V
LTC6078DD, LTC6079DHC
VCM = 0.5V, 2.5V
LTC6078AMS8
VCM = 0.5V
LTC6078MS8
VCM = 0.5V
LTC6079GN
VCM = 0.5V
LTC6078DD
VCM = 0.5V
LTC6079DHC
VCM = 0.5V
●
●
●
●
●
LTC6078AMS8
LTC6078MS8
LTC6078DD, LTC6079GN
LTC6079DHC
●
●
●
●
TYP
MAX
±7
±7
±20
±25
±30
±30
±35
±25
±30
±70
±97
±115
±120
±150
±0.2
H SUFFIX
MIN
UNITS
TYP
MAX
±7
±25
±25
±30
±35
±95
±135
±165
±0.2
±0.3
±0.3
±0.7
±1.1
±1.4
±1.8
±0.3
±0.7
±1.1
±1.4
μV/°C
μV/°C
μV/°C
μV/°C
μV
μV
μV
μV
μV
μV
μV
IB
Input Bias Current
(Note 6)
VCM = V+/2
VCM = V+/2
●
0.2
10
1
50
0.2
150
1
350
pA
pA
IOS
Input Offset Current
(Note 6)
VCM = V+/2
VCM = V+/2
●
0.1
0.5
25
0.1
10
100
pA
pA
Input Noise Voltage
0.1Hz to 10Hz
1
1
µVP-P
Input Noise Voltage Density
f = 1kHz
f = 10kHz
18
16
18
16
nV/√Hz
nV/√Hz
0.56
0.56
fA/√Hz
en
in
Input Noise Current Density
(Note 8)
●
Input Common Mode Range
V–
V+
V–
V+
V
CDIFF
Differential Input Capacitance
10
10
pF
CCM
Common Mode Input
Capacitance
18
18
pF
CMRR
Common Mode Rejection
Ratio
PSRR
VOUT
All Packages
LTC6078AMS8
LTC6078AMS8
LTC6078MS8
LTC6078MS8
LTC6079GN
LTC6079GN
LTC6078DD, LTC6079DHC
LTC6078DD, LTC6079DHC
VCM = 0V to 3V
VCM = 0V to 3V
VCM = 0V to 1.7V
VCM = 0V to 3V
VCM = 0V to 1.7V
VCM = 0V to 3V
VCM = 0V to 1.7V
VCM = 0V to 3V
VCM = 0V to 1.7V
Power Supply Rejection Ratio VS = 2.7V to 5.5V
●
●
●
●
●
●
●
●
95
87
91
85
89
84
88
83
87
110
105
103
102
102
102
102
100
102
95
87
91
85
89
84
88
110
103
103
100
102
100
102
dB
dB
dB
dB
dB
dB
dB
dB
dB
100
97
120
100
97
120
●
dB
dB
35
350
1
15
150
mV
mV
mV
Output Voltage, High
(Referred to V+)
No Load
ISOURCE = 0.2mA
ISOURCE = 2mA
●
●
Output Voltage, Low
(Referred to V–)
No Load
ISINK = 0.2mA
ISINK = 2mA
●
●
1
15
150
1
10
100
40
400
1
10
100
30
300
35
350
mV
mV
mV
AVOL
Large-Signal Voltage Gain
RLOAD = 10k, 0.5V ≤ VOUT ≤ 2.5V
●
115
130
110
125
dB
ISC
Output Short-Circuit Current
Source
Sink
●
●
5
7
10
14
4
6
10
14
mA
mA
SR
Slew Rate
AV = 1
0.05
V/μs
GBW
Gain-Bandwidth Product
(fTEST = 10kHz)
RL = 100k
750
kHz
kHz
Φ0
Phase Margin
RL = 10k, CL = 200pF
66
66
Deg
tS
Settling Time 0.1%
AV = 1, 1V Step
24
24
μs
0.05
●
420
360
750
420
320
60789fa
3
LTC6078/LTC6079
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 3V, V– = 0V, VCM = 0.5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
C, I SUFFIXES
MIN
IS
VS
tON
tOFF
Supply Current
(per Amplifier)
No Load
Shutdown Current
(per Amplifier)
Shutdown, VSHDN ≤ 0.8V, LTC6078DD
●
Supply Voltage Range
Guaranteed by the PSRR Test
●
Channel Separation
fs = 10kHz, RL = 10k
Shutdown Logic
SHDN High, LTC6078DD
SHDN Low, LTC6078DD
MAX
54
72
78
0.3
1
●
Turn on Time
VSHDN = 0.8V to 2V, LTC6078DD
Turn off Time
VSHDN = 2V to 0.8V, LTC6078DD
Leakage of SHDN Pin
VSHDN = 0V, LTC6078DD
H SUFFIX
TYP
2.7
5.5
MIN
MAX
54
72
80
2.7
5.5
–110
2
μA
μA
μA
–110
●
●
UNITS
TYP
dB
2
0.8
0.8
50
50
2
2
V
V
V
µs
µs
0.6
μA
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. Test
conditions are V+ = 5V, V– = 0V, VCM = 0.5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
C, I SUFFIXES
MIN
VOS
Offset Voltage
ΔVOS ⁄ΔT Input Offset Voltage Drift
(Note 7)
IB
Input Bias Current
IOS
Input Offset Current
en
in
TYP
MAX
±10
±10
±20
±25
±30
±30
±35
±0.2
H SUFFIX
MIN
UNITS
TYP
MAX
±30
±35
±75
±102
±120
±125
±155
±10
±30
±25
±30
±35
±100
±140
±170
±0.2
±0.3
±0.3
±0.7
±1.1
±1.4
±1.8
±0.3
±0.7
±1.1
±1.4
μV/°C
μV/°C
μV/°C
μV/°C
LTC6078MS8, LTC6078AMS8, LTC6079GN
VCM = 0.5V
LTC6078DD, LTC6079DHC
VCM = 0.5V
LTC6078AMS8
VCM = 0.5V
LTC6078MS8
VCM = 0.5V
LTC6079GN
VCM = 0.5V
LTC6078DD
VCM = 0.5V
LTC6079DHC
VCM = 0.5V
●
●
●
●
●
LTC6078AMS8
LTC6078MS8
LTC6078DD, LTC6079GN
LTC6079DHC
●
●
●
●
VCM = V+/2
VCM = V+/2
●
0.2
10
1
50
0.2
150
1
350
pA
pA
VCM = V+/2
VCM = V+/2
●
0.1
0.5
25
0.1
10
100
pA
pA
μV
μV
μV
μV
μV
μV
μV
Input Noise Voltage
0.1Hz to 10Hz
1
1
µVP-P
Input Noise Voltage Density
f = 1kHz
f = 10kHz
18
16
18
16
nV/√Hz
nV/√Hz
0.56
0.56
fA/√Hz
Input Noise Current Density
(Note 8)
Input Common Mode Range
●
V–
V+
V–
V+
V
CDIFF
Differential Input Capacitance
10
10
pF
CCM
Common Mode Input
Capacitance
18
18
pF
60789fa
4
LTC6078/LTC6079
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 5V, V– = 0V, VCM = 0.5V unless otherwise noted.
SYMBOL PARAMETER
CMRR
PSRR
Common Mode Rejection
Ratio
CONDITIONS
All Packages
LTC6078AMS8
LTC6078AMS8
LTC6078MS8
LTC6078MS8
LTC6079GN
LTC6079GN
LTC6078DD, LTC6079DHC
LTC6078DD, LTC6079DHC
C, I SUFFIXES
VCM = 0V to 5V
VCM = 0V to 5V
VCM = 0V to 3.7V
VCM = 0V to 5V
VCM = 0V to 3.7V
VCM = 0V to 5V
VCM = 0V to 3.7V
VCM = 0V to 5V
VCM = 0V to 3.7V
Power Supply Rejection Ratio VS = 2.7V to 5.5V
MIN
TYP
●
●
●
●
●
●
●
●
91
90
94
88
90
86
90
86
90
105
105
105
100
105
100
105
100
105
100
97
120
●
50
500
H SUFFIX
MAX
UNITS
MIN
TYP
MAX
91
90
94
88
90
86
90
105
105
105
100
105
100
105
dB
dB
dB
dB
dB
dB
dB
dB
dB
120
dB
dB
2
20
200
mV
mV
mV
97
Output Voltage, High
(Referred to V+)
No Load
ISOURCE = 0.5mA
ISOURCE = 5mA
●
●
Output Voltage, Low
(Referred to V–)
No Load
ISINK = 0.5mA
ISINK = 5mA
●
●
AVOL
Large-Signal Voltage Gain
RLOAD = 10k, 0.5V ≤ VOUT ≤ 4.5V
●
115
130
110
125
dB
ISC
Output Short-Circuit Current
Source
Sink
●
●
14
14
25
25
12
12
25
25
mA
mA
SR
Slew Rate
AV = 1
0.05
V/μs
GBW
Gain-Bandwidth Product
(fTEST = 10kHz)
RL = 100k
750
kHz
kHz
Φ0
Phase Margin
RL = 10k, CL = 200pF
66
66
Deg
tS
Settling Time 0.1%
AV = 1, 1V Step
24
24
μs
IS
Supply Current
(per Amplifier)
No Load
Shutdown Current
(per Amplifier)
Shutdown, VSHDN ≤ 1.2V, LTC6078DD
●
Supply Voltage Range
Guaranteed by the PSRR Test
●
2.7
Channel Separation
fs = 10kHz, RL = 10k
Shutdown Logic
SHDN High, LTC6078DD
SHDN Low, LTC6078DD
●
●
3.5
VOUT
VS
2
20
200
1
15
150
55
550
1
15
150
40
400
0.05
●
420
360
750
420
320
45
450
mV
mV
mV
55
74
82
55
74
84
μA
μA
1.5
5
1.5
5
μA
5.5
V
●
5.5
2.7
–110
–110
dB
3.5
1.2
1.2
V
V
tON
Turn on Time
VSHDN = 1.2V to 3.5V, LTC6078DD
50
50
µs
tOFF
Turn off Time
VSHDN = 1.2V to 3.5V, LTC6078DD
2
2
µs
Leakage of SHDN Pin
VSHDN = 0V, LTC6078DD
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: A heat sink may be required to keep the junction temperature
below the absolute maximum. This depends on the power supply voltage
and how many amplifiers are shorted.
Note 3: The LTC6078C/LTC6079C and LTC6078I/LTC6079I are guaranteed
functional over the operating temperature range of –40°C to 85°C. The
LTC6078H/LTC6079H are guaranteed functional over the operating
temperature range of –40°C to 125°C.
Note 4: The LTC6078C/LTC6079C are guaranteed to meet specified
0.6
μA
performance from 0°C to 70°C. The LTC6078C/LTC6079C are designed,
characterized and expected to meet specified performance from –40°C
to 85°C but are not tested or QA sampled at these temperatures. The
LTC6078I/LTC6079I are guaranteed to meet specified performance from
–40°C to 85°C. The LTC6078H/LTC6079H are guaranteed to meet specified
performance from –40°C to 125°C.
Note 5: VOS and VOS drift are 100% tested at 25°C and 125°C.
Note 6: IB and IOS are guaranteed by the VS = 5V test.
Note 7: VOS drift is guaranteed by the VS = 3V test.
Note 8: Current noise is calculated from in = √2qIB, where q = 1.6 • 10–19
coulomb.
60789fa
5
LTC6078/LTC6079
U W
TYPICAL PERFOR A CE CHARACTERISTICS
VOS vs VCM
VOS Distribution
14
40
VS = 3V
TA = 25°C
REPRESENTATIVE PARTS
30
VS = 5V
80 TA = 25°C
REPRESENTATIVE PARTS
60
20
6
VOS (µV)
VOS (µV)
8
40
10
0
–10
4
–60
2
–30
–80
0
–11 –9 –7 –5 –3 –1 1
VOS (µV)
–40
–100
3
5
7
9
0
0.5
1.0
2.0
1.5
VCM (V)
2.5
VOS Drift Distribution
Input Bias vs VCM
25
20
15
10
VS = 5V
160 VCM = 2.5V
30
140
18
120
100
80
60
40
5
20
0
0
25
50
75
100
TEMPERATURE (°C)
60789 G04
–12
125
–30
NOISE VOLTAGE (nV/√Hz)
100
–0
–100
–200
–300
5
VCM (V)
60789 G07
3
2
4
5
60789 G06
0.1Hz to 10Hz Output Voltage
Noise
70
60
50
40
30
VS = 3V
VCM = 0.5V
20
VS = 5V
VCM = 0.5V
0
4
1
VS = 5V
VCM = 0.5V
10
3
0
VCM (V)
80
200
TA = 85°C
–18
90
VS = 5V
TA = 125°C
300
TA = 70°C
–6
Voltage Noise Spectrum
400
2
6
–0
60789 G05
Input Bias vs VCM
1
12
–24
0
–0.8 –0.6 –0.4 –0.2 0 0.2 0.4 0.6 0.8
µV/°C
VS = 5V
24
INPUT BIAS CURRENT (pA)
INPUT BIAS CURRENT (pA)
30
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
VCM (V)
60789 G03
Input Bias vs Temperature
35
0
0
180
LTC6078MS8
45 VS = 3V
VCM = 0.5V
40 T = –40°C TO 125°C
A
–400
3.0
60789 G02
50
NUMBER OF AMPS OUT OF 200
0
–20
–40
–20
60789 G01
INPUT BIAS CURRENT (pA)
20
VOLTAGE NOISE (500nV/DIV)
NUMBER OF AMPS OUT OF 200
LTC6078MS8
VS = 3V
12 VCM = 0.5V
TA = 25°C
10
VOS vs VCM
100
1
10
100
1k
FREQUENCY (Hz)
10k
100k
TIME (5s/DIV)
60789 G09
60789 G08
60789fa
6
LTC6078/LTC6079
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Output Voltage Swing vs
Load Current
Supply Current vs Supply Voltage
+VS
50
SOURCE
SUPPLY CURRENT (µA)
+VS –1.0
+VS –1.5
+VS –2.0
VS = 5V
VCM = 0.7V
–VS +2.0
–VS +1.5
TA = 125°C
TA = 25°C
TA = –55°C
–VS +1.0
–VS +0.5
65
40
30
20
10
SINK
0.1
1
10
LOAD CURRENT (mA)
60789 G10
80
100
60
80
40
40
20
20
0
0
VS = 5V
–20 VCM = 0.5V
CL = 200pF
TA = 25°C
–40
10k
1k
VS = 5V
VCM = 0.5V
TA = 25°C
120
100
60
40
80
60
20
40
0
20
GAIN
–20
100k
1M
FREQUENCY (Hz)
–40
10M
–20
100
0
1k
10k
100k
FREQUENCY (Hz)
1M
1
10M
10
100 1k 10k 100k
FREQUENCY (Hz)
60789 G14
1M
10M
60789 G15
Small Signal Transient
Output Impedance vs Frequency
OUTPUT IMPEDANCE (Ω)
PSRR vs Frequency
140
VS = 5V
VCM = 0.5V
TA = 25°C
RL = 1k
60789 G13
1000
60789 G12
PSRR (dB)
120
CMRR (dB)
PHASE
100
PHASE (DEG)
GAIN (dB)
60
50
CMRR vs Frequency
RL = 10k
RL = 100k
80
VS = 3V
60789 G11
Open Loop Gain vs Frequency
100
55
40
–40 –25 –10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
100
VS = 5V
45
PER AMPLIFIER
VCM = 0.5V
TA = 25°C
0
–VS
0.01
PER AMPLIFIER
VCM = 0.5V
60
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE SWING (V)
(REFERRED TO SUPPLY VOLTAGE)
+VS –0.5
10000
Supply Current vs Temperature
60
Large Signal Transient
VS = 5V
VCM = 0.5V
TA = 25°C
100
AV = 100
AV = 10
20mV/DIV
1V/DIV
10
AV = 1
1
0.1
0.01
100
20µs/DIV
1k
10k
100k
1M
VS = 5V
RL = 10k
CL = 100pF
60789 G17
200µs/DIV
60789 G18
VS = 5V
RL = 10k
CL = 100pF
FREQUENCY (Hz)
60789 G16
60789fa
7
LTC6078/LTC6079
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Disabled Output Impedence vs
Frequency
50
10
1
35
30
AV = 1
25
20
15
AV = 10
10
0.1
VS = 5V
VCM = 0.5V
–105 RL = 10k
CHANNEL SEPARATION (dB)
100
–100
VS = 5V
45 VCM = 0.5V
TA = 25°C
40
VS = 5V
VCM = 0.5V
TA = 25°C
AV = 1
OVERSHOOT (%)
OUTPUT IMPEDANCE (kΩ)
1000
Channel Separation vs Frequency
Overshoot vs CL
0
1k
10k
100k
FREQUENCY (Hz)
1M
10M
60789 G19
–115
–120
–125
–130
5
0.01
100
–110
10
100
CAPACITIVE LOAD (pF)
1000
–135
100
1k
60789 G20
10k
100k
FREQUENCY (Hz)
1M
10M
60789 G21
U
U
U
PI FU CTIO S
OUT: Amplifier Output
–IN: Inverting Input
+IN: Noninverting Input
V+: Positive Supply
V–: Negative Supply
⎯ ⎯H⎯D⎯N⎯_⎯A: Shutdown Pin of Amplifier A, active low and only
S
valid for LTC6078DD. An internal current source pulls the
pin to V+ when floating.
⎯ ⎯H⎯D⎯N⎯_⎯B: Shutdown Pin of Amplifier B, active low and only
S
valid for LTC6078DD. An internal current source pulls the
pin to V+ when floating.
NC: Not internally connected.
Exposed Pad: Connected to V–.
60789fa
8
LTC6078/LTC6079
U
U
W
U
APPLICATIO S I FOR ATIO
Preserving Input Precision
Capacitive Load
Preserving input accuracy of the LTC6078/LTC6079 requires that the application circuit and PC board layout do
not introduce errors comparable or greater than the 10µV
typical offset of the amplifiers. Temperature differentials
across the input connections can generate thermocouple
voltages of 10’s of microvolts so the connections to the
input leads should be short, close together and away from
heat dissipating components. Air current across the board
can also generate temperature differentials.
LTC6078/LTC6079 can drive capactive load up to 200pF in
unity gain. The capacitive load driving capability increases
as the amplifier is used in higher gain configurations. A
small series resistance between the ouput and the load
further increases the amount of capacitance the amplifier
can drive.
Input Clamps
Large differential voltages across the inputs over very
long time periods can impact the precisely trimmed input
offset voltage of the LTC6078/LTC6079. As an example,
a 2V differential voltage between the inputs over a period
of 100 hours can shift the input offset voltage by tens
of microvolts. If the amplifier is to be subjected to large
differential input voltages, adding back-to-back diodes
between the two inputs will minimize this shift and retain
the DC precision. If necessary, current-limiting series
resistors can be added in front of the diodes, as shown
in Figure 1. These diodes are not necessary for normal
closed loop applications.
500Ω
500Ω
+
–
60789 F01
Figure 1. Op Amp with Input Voltage Clamp
Pins 5 and 6 are used for power shutdown on the LTC6078
in the DD package. If they are floating, internal current
sources pull Pins 5 and 6 to V+ and the amplifiers operate
normally. In shutdown, the amplifier output is high impedance, and each amplifier draws less than 2µA current.
When the chip is turned on, the supply current per amplifier
is about 35µA larger than its normal values for 50µs.
Rail-to-Rail Input
The input stage of LTC6078/LTC6079 combines both PMOS
and NMOS differential pairs, extending its input common
mode voltage range to both positive and negative supply
voltages. At high input common mode range, the NMOS
pair is on. At low common mode range, the PMOS pair is
on. The transition happens when the common voltage is
between 1.3V and 0.9V below the positive supply.
Thermal Hysteresis
Figure 2 shows the input offset hysteresis of LTC6078MS8
for 3 thermal cycles from –45°C to 90°C. The typical offset
shift after the 3 cycles is only 1µV.
50
VS = 3V
45 VCM = 0.5V
NUMBER OF AMPLIFIERS
The extremely low input bias currents (0.2pA typical) allow high accuracy to be maintained with high impedance
sources and feedback resistors. Leakage currents on the
PC board can be higher than the input bias current. For
example, 10GΩ of leakage between a 5V supply lead and
an input lead will generate 500pA! Surround the input
leads with a guard ring driven to the same potential as the
input common mode to avoid excessive leakage in high
impedance applications.
⎯S⎯H⎯D⎯N Pins
40
35
1ST CYCLE
2ND CYCLE
3RD CYCLE
30
25
20
15
10
5
0
–5 –4 –3 –2 –1 0 1 2 3 4 5
VOS CHANGE FROM INITIAL VALUE
6
60789 F02
Figure 2. VOS Thermal Hysteresis of LTC6078MS8
60789fa
9
LTC6078/LTC6079
U
U
W
U
APPLICATIO S I FOR ATIO
PC Board Layout
the fourth side. Figure 3 shows the layout of a LTC6078DD
with slots at three sides.
Mechanical stress on a PC board and soldering-induced
stress can cause the VOS and VOS drift to shift. The DD
and DHC packages are more sensitive to stress. A simple
way to reduce the stress-related shifts is to mount the IC
near the short edge of the PC board, or in a corner. The
board edge acts as a stress boundary, or a region where
the flexure of the board is minimum. The package should
always be mounted so that the leads absorb the stress and
not the package. The package is generally aligned with the
leads paralled to the long side of the PC board.
LONG DIMENSION
SLOTS
The most effective technique to relieve the PC board stress
is to cut slots in the board around the op amp. These slots
can be cut on three sides of the IC and the leads can exit on
60789 F03
Figure 3. Vertical Orientation of LTC6078DD with Slots
W
W
SI PLIFIED SCHE ATIC
V+
R1
M10
R2
M11
M8
C1
I1
+
V+
I2
V–
–
1µA
A1
VBIAS
D4
M5
V+
+IN
V+
M1
V–
OUTPUT
CONTROL
M6 M7
M2
D8
V–
D5
A2
+
–
BIAS
GENERATION
V–
C2
D1
NOTE: SHDN IS ONLY AVAILABLE
IN THE DFN10 PACKAGE
V–
OUT
D6
–IN
D2
SHDN
D7
V+
D3
M3
M9
M4
R3
V–
R4
60789 SS
Simplified Schematic of the Amplifier
60789fa
10
LTC6078/LTC6079
U
TYPICAL APPLICATIO S
2.7V High Side Current Sense
VDD
VDD
R1
+
RS
1/2
LTC6078
2N7002
–
IL
VOUT
R2
LOAD
VOUT = IL •
R2
R2
• R – VOS •
R1 S
R1
0V ≤ VOUT ≤ VDD – VGS, MOSFET
60789 TA02
Low Average Power IR LED Driver
VDD
VDD
5V
0V
ON/OFF
909k
HSDL-4220
+
1/2
LTC6078
100k
–
2N7002
SHDN
49.9Ω
VARYING ON DUTY CYCLE REDUCES
AVERAGE POWER CONSUMPTION
60789 TA03
Accelerometer Signal Conditioner
2.5V
COLUMBIA RESEARCH LABS
3021 ACCELERATOR
+
1/2
LTC6078
VOUT
–
1M
–2.5V
VOUT = 60mV/g
WHERE g = EARTH'S GRAVITATIONAL CONSTANT
1000pF
60789 TA04
Photodiode Amplifier
2.5V
1M
–
TEMD1000
IR PHOTODIODE
1/2
LTC6078
3.8pF
VOUT
+
–2.5V
AT 870nm (IR),
VOUT = 600mV/µW RECEIVED POWER
60789 TA05
60789fa
11
LTC6078/LTC6079
U
TYPICAL APPLICATIO S
6 Decade Current Log Amplifier
–
C
+
100Ω
+
B
100Ω
–
33µF
Q2
Q1
100k
133k
VDD
–
1000pF
–
A
1.58k
+
D
+
IIN
PRECISION
RESISTOR PT146
1k
+3500ppm/°C
VOUT
LT6650
VCC
IN
1µF
OUT
GND
10nA ≤ IIN ≤ 10mA
Q1, Q2: DIODES INC. DMMT3906W
A TO D: LTC6079
VOUT ≈ 150mV • log (IIN) + 1.23V, IIN IN AMPS
1µF
60789 TA07
Humidity Sensor Signal Conditioner
VSUP
5.2V TO 20V
IN
1µF
VDD
5V
OUT
LT1761-5
0.01µF
1µF
SHDN BYP
VDD
VDD
49.9k
100k
VBIAS
49.9k
100k
M1
GAIN TRIM
BAT54S
75pF
VDD
H
100k
LTC6906
VDD
0.1µF
–
100k
A
VBIAS
DIV
–
499k
OUT
GRD GND
SET
34.8k
1000pF
+
1k
B
A TO C: LTC6079
H: GE PARAMETRICS G-CAP 2 HUMIDITY SENSOR
148pF TO 178pF, 0% TO 90% RH
M1: VN2222L
VOUT
0V TO 5V
0% TO 100% RH
C
+
VDD
10k
1M
–
+
0.1µF
VDD
1k
47.5k
100k
60789 TA08
OFFSET TRIM
60789fa
12
LTC6078/LTC6079
U
TYPICAL APPLICATIO S
LDO Load Balancing
VIN
1.8V TO 20V
IN
+
LT1763
10µF
BALLAST RESISTANCE:
IDENTICAL LENGTH
THERMALLY MATED
WIRE OR PCB TRACE
OUT
0.01µF
10µF
SHDN BYP
FB
R1
2k
R2
2k
IN
⎛ R1⎞
VOUT = 1.22V ⎜1 + ⎟
⎝ R2⎠
OUT
LT1763
0.01µF
10µF
SHDN BYP
100Ω
ILOAD
FB
LOAD
2k
2k
1k
0.1µF
–
A
10k
IN
+
OUT
LT1763
0.01µF
10µF
SHDN BYP
100Ω
FB
2k
0 ≤ ILOAD ≤ 1.5A
1.22V ≤ VOUT ≤ VDD
LDO LOADS MATCH TO WITHIN
1mA WITH 10mΩ OF BALLAST
RESISTANCE (2 INCHES OF AWG
28 GAUGE STRANDED WIRE)
A, B: LTC6078
2k
0.1µF
1k
VDD
–
B
10k
+
60789 TA09
pH Probe Amplifier
PRECISION
RESISTOR PT146
1k
+3500ppm/°C
+
1k
A
pH
–
VCC
–
57.6k
LT1634
1.25V
VOUT
B
+
1000pF
SENSOR: SENSOREX S200C pH PROBE
LTC6078 INPUT IMPEDANCE ≈ 1TΩ OR GREATER
VOUT = 1.25V + 59.2mV • (pH – 7)
A, B: LTC6078
60789 TA10
60789fa
13
LTC6078/LTC6079
U
TYPICAL APPLICATIO S
Thermistor Amplifier with Overtemperature Alarm
VDD
–
1k
LT1634
1.25V
29.4k
0.01µF
71.5k
200k
D
TOV
C
VOUT
+
+
+
B
3200Ω
–
+
YSI #44201
THERMOLINEAR
NETWORK
–
A
6250Ω
100k
–
100k
143k
H
178k
100k
60789 TA12
B
20k
50k
OFFSET TRIM
GAIN TRIM
A TO D: LTC6079, VDD = 2.7V TO 5.5V, VSS = GND
VOUT = 0 → 1V FOR 0°C TO 100°C, LINEAR
TOV → HIGH WHEN T ≥ 90°C
Precision Sample-and-Hold
VDD
LTC6943
6
–
9
VIN
+
–
7
LTC6078
A
LTC6078
B
5
+
1
4
14
S/H
VOUT
0.1µF
ISUPPLY < 200µA
VOLTAGE DROOP = 130nV/ms TYP
SLEW RATE = 0.05V/ms TYP
ACQ TIME = 84µs TYP TO 0.1%
60789 TA13
60789fa
14
LTC6078/LTC6079
U
TYPICAL APPLICATIO S
Precision Voltage-Controlled Current Source
VDD
+
VIN
1/2
LTC6078
–
IOUT =
VIN
RSET
IERROR < 0.1% AT IOUT = 1µA
0.68µF
1k
6
7
9
1µF
RSET
1k
1µF
10
11
12
15
IOUT
LTC6943
14
0.001µF
60789 TA14
60Hz Notch
R2
2.5V
–
R1
1/2
LTC6078
10M
10M
+
540pF
–2.5V
270pF
270pF
VOUT
VIN
( )
VOUT = 1 + R2 • VIN
R1
5M
NOTCH DEPTH = –60dB AT 60Hz, RTI
60789 TA15
60789fa
15
LTC6078/LTC6079
U
PACKAGE DESCRIPTIO
DD Package
10-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1699)
0.675 ±0.05
3.50 ±0.05
1.65 ±0.05
2.15 ±0.05 (2 SIDES)
PACKAGE
OUTLINE
0.25 ± 0.05
0.50
BSC
2.38 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
R = 0.115
TYP
6
3.00 ±0.10
(4 SIDES)
0.38 ± 0.10
10
1.65 ± 0.10
(2 SIDES)
PIN 1
TOP MARK
(SEE NOTE 6)
(DD10) DFN 1103
5
0.200 REF
1
0.75 ±0.05
0.00 – 0.05
0.25 ± 0.05
0.50 BSC
2.38 ±0.10
(2 SIDES)
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2).
CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE
60789fa
16
LTC6078/LTC6079
U
PACKAGE DESCRIPTIO
DHC Package
16-Lead Plastic DFN (5mm × 3mm)
(Reference LTC DWG # 05-08-1706)
0.65 ±0.05
3.50 ±0.05
1.65 ±0.05
2.20 ±0.05 (2 SIDES)
PACKAGE
OUTLINE
0.25 ± 0.05
0.50 BSC
4.40 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
R = 0.115
TYP
5.00 ±0.10
(2 SIDES)
R = 0.20
TYP
3.00 ±0.10
(2 SIDES)
9
0.40 ± 0.10
16
1.65 ± 0.10
(2 SIDES)
PIN 1
TOP MARK
(SEE NOTE 6)
PIN 1
NOTCH
(DHC16) DFN 1103
8
0.200 REF
1
0.25 ± 0.05
0.50 BSC
0.75 ±0.05
4.40 ±0.10
(2 SIDES)
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING PROPOSED TO BE MADE VARIATION OF VERSION (WJED-1) IN JEDEC
PACKAGE OUTLINE MO-229
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE
60789fa
17
LTC6078/LTC6079
U
PACKAGE DESCRIPTIO
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
0.889 ± 0.127
(.035 ± .005)
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
0.42 ± 0.038
(.0165 ± .0015)
TYP
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.65
(.0256)
BSC
8
7 6 5
0.52
(.0205)
REF
RECOMMENDED SOLDER PAD LAYOUT
0.254
(.010)
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
4.90 ± 0.152
(.193 ± .006)
DETAIL “A”
0° – 6° TYP
GAUGE PLANE
1
0.53 ± 0.152
(.021 ± .006)
DETAIL “A”
2 3
4
1.10
(.043)
MAX
0.86
(.034)
REF
0.18
(.007)
SEATING
PLANE
0.22 – 0.38
(.009 – .015)
TYP
0.65
(.0256)
BSC
0.127 ± 0.076
(.005 ± .003)
MSOP (MS8) 0204
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
60789fa
18
LTC6078/LTC6079
U
PACKAGE DESCRIPTIO
GN Package
16-Lead Plastic SSOP (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1641)
.189 – .196*
(4.801 – 4.978)
.045 ±.005
16 15 14 13 12 11 10 9
.254 MIN
.009
(0.229)
REF
.150 – .165
.229 – .244
(5.817 – 6.198)
.0165 ± .0015
.150 – .157**
(3.810 – 3.988)
.0250 BSC
RECOMMENDED SOLDER PAD LAYOUT
1
.015 ± .004
× 45°
(0.38 ± 0.10)
.007 – .0098
(0.178 – 0.249)
2 3
4
5 6
7
.0532 – .0688
(1.35 – 1.75)
8
.004 – .0098
(0.102 – 0.249)
0° – 8° TYP
.016 – .050
(0.406 – 1.270)
NOTE:
1. CONTROLLING DIMENSION: INCHES
INCHES
2. DIMENSIONS ARE IN
(MILLIMETERS)
.008 – .012
(0.203 – 0.305)
TYP
.0250
(0.635)
BSC
GN16 (SSOP) 0204
3. DRAWING NOT TO SCALE
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
60789fa
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
19
LTC6078/LTC6079
U
TYPICAL APPLICATIO
DC Accurate Composite Amplifier, Gain of 1000
VCC
+
VIN
LT1226
1M
VDD
–
0.1µF
VEE
–
1/2
LTC6078
VCC
VOUT
+
10k
100Ω
10Ω
2.49k
10k
VSS
VDD
LT1634BCS8-5
10Ω
VSS
CIRCUIT BW ≈ 1.25MHz
en = 2.6nV/√Hz (RTI) AT 1kHz
CIRCUIT VOS = 25µV (MAX) RTI
2.49k
VEE
60789 TA06
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC2051/LTC2052
Dual/Quad Zero-Drift Op Amps
3µV VOS, 30nV/°C VOS Drift
LT6011/LT6012
Dual/Quad Precision Op Amps
60µV VOS, IB = 300pA, IS = 135µA
60789fa
20 Linear Technology Corporation
LT 0506 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2005