LTC6087/LTC6088 Dual/Quad 14MHz, Rail-to-Rail CMOS Amplifiers FEATURES
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DESCRIPTION
The LTC®6087/LTC6088 are dual/quad, low noise, low offset, rail-to-rail input/output, unity-gain stable CMOS operational amplifiers that feature 1pA of input bias current. A 14MHz gain bandwidth and 7.2V/μs slew rate, combined with low noise (10nV/√Hz) and a low 0.75mV offset, make the LTC6087/LTC6088 useful in a variety of applications. The 1.1mA supply current and the shutdown mode are ideal for signal processing applications which demand performance with minimal power. The LTC6087/LTC6088 has an output stage which swings within 30mV of either supply rail to maximize signal dynamic range in low supply applications. The input common mode range includes the entire supply voltage. These op amps are specified on power supply voltages of 3V and 5V from –40°C to 125°C. The dual amplifier LTC6087 is available in 8-lead MSOP and 10-lead DFN packages. The quad amplifier LTC6088 is available in 16-lead SSOP and DFN packages.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
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Low Offset Voltage: 750μV Maximum Low Offset Drift: 5μV/°C Maximum Input Bias Current: 1pA (Typical at 25°C) 15pA (Typical at 85°C) Rail-to-Rail Inputs and Outputs Gain Bandwidth Product: 14MHz CMRR: 70dB Minimum PSRR: 93dB Minimum Input Noise Voltage Density: 12nV/√Hz Supply Current: 1.1mA per Amp Shutdown Current: 2.3μA per Amp 2.7V to 5.5V Operation Voltage Available in 8-Lead MSOP and 10-Lead DFN Packages (LTC6087), 16-Lead SSOP and DFN Packages (LTC6088)
APPLICATIONS
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Portable Test Equipment Medical Equipment Audio Data Acquisition High Impedance Transducer Amplifier
TYPICAL APPLICATION
Single Supply Shock/Vibration Sensor Amplifier
1000 MURATA SHOCK SENSOR PKGS-00MX1 520pF 0.57pC/g , www.murata.com
LTC6087 Input Bias Current vs Temperature
VS = 5V VCM = 2.5V
100k
VS
INPUT BIAS CURRENT (pA)
VS
100
+
100k 0.1μF 1/2 LTC6087
+
1/2 LTC6087 VOUT 570mV/g 16Hz TO 10kHz VS = 2.7V TO 5.5V
60878 TA01a
–
1k 1% 100M 100pF
–
100k 1%
10
1 25 40 55 70 85 100 TEMPERATURE (°C) 115 130
60878 TA01b
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LTC6087/LTC6088 ABSOLUTE MAXIMUM RATINGS
(Note 1)
Total Supply Voltage (V+ to V–) ...................................6V Input Voltage...................................................... V– to V+ Input Current....................................................... ±10mA SHDNA/SHDNB Voltage ..................................... V– to V+ Output Short-Circuit Duration (Note 2) ............ Indefinite Operating Temperature Range (Note 3) LTC6087C/LTC6088C ........................... –40°C to 85°C LTC6087H/LTC6088H ......................... –40°C to 125°C
Specified Temperature Range (Note 4) LTC6087C/LTC6088C ............................... 0°C to 70°C LTC6087H/LTC6088H ......................... –40°C to 125°C Junction Temperature ........................................... 150°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) MS8, GN16 Only ............................................... 300°C
PIN CONFIGURATION
TOP VIEW TOP VIEW
+ –
OUTA 8 7 6 5 V+ OUTB –INB +INB –INA +INA V– SHDNA
1
+ –
10 V+ A 9 OUTB 11 B 8 –INB 7 +INB 6 SHDNB
+ –
B
MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 200°C/W
TOP VIEW OUTA –INA +INA V+ +INB –INB OUTB NC 1 A D
+ – + –
2 3 4 5 6 7 8
15 –IND 14 +IND 13 V–
+INA V+ +INB –INB OUTB NC
3 4 5 6 7 8
A
D
17
+ –B
+ –B
C–
+
12 +INC 11 –INC 10 OUTC 9 NC
C–
+
GN PACKAGE 16-LEAD PLASTIC SSOP NARROW TJMAX = 150°C, θJA = 110°C/W
DHC PACKAGE 16-LEAD (5mm × 3mm) PLASTIC DFN TJMAX = 150°C, θJA = 43°C/W EXPOSED PAD (PIN 17) IS V–, MUST BE SOLDERED TO PCB
2
+ –
+ –
+ –
OUTA –INA +INA V–
1 2 3 4
2 3 4 5
A
DD PACKAGE 10-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 150°C, θJA = 43°C/W EXPOSED PAD (PIN 11) IS V–, MUST BE SOLDERED TO PCB TOP VIEW
16 OUTD
OUTA –INA
1 2
16 OUTD 15 –IND 14 +IND 13 V– 12 +INC 11 –INC 10 OUTC 9 NC
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LTC6087/LTC6088 ORDER INFORMATION
LEAD FREE FINISH LTC6087CDD#PBF LTC6087HDD#PBF LTC6087CMS8#PBF LTC6087HMS8#PBF LTC6088CDHC#PBF LTC6088HDHC#PBF LTC6088CGN#PBF LTC6088HGN#PBF TAPE AND REEL LTC6087CDD#TRPBF LTC6087HDD#TRPBF LTC6087CMS8#TRPBF LTC6087HMS8#TRPBF LTC6088CDHC#TRPBF LTC6088HDHC#TRPBF LTC6088CGN#TRPBF LTC6088HGN#TRPBF PART MARKING* LCTX LCTX LTCTY LTCTY 6088 6088 6088 6088H PACKAGE DESCRIPTION 10-Lead (3mm × 3mm) Plastic DFN 10-Lead (3mm × 3mm) Plastic DFN 8-Lead Plastic MSOP 8-Lead Plastic MSOP 16-Lead (5mm × 3mm) Plastic DFN 16-Lead (5mm × 3mm) Plastic DFN 16-Lead Plastic SSOP 16-Lead Plastic SSOP TEMPERATURE RANGE –40°C to 85°C –40°C to 125°C –40°C to 85°C –40°C to 125°C –40°C to 85°C –40°C to 125°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/
The l denotes the specifications which apply over the full specified temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 3V, V– = 0V, VCM = 0.5V unless otherwise noted.
C SUFFIX SYMBOL PARAMETER VOS Offset Voltage (Note 5) CONDITIONS LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC Guaranteed by 5V Test
●
ELECTRICAL CHARACTERISTICS
H SUFFIX MAX MIN TYP MAX UNITS μV μV μV μV μV/°C μV/°C pA pA pA pA nV/√Hz nV/√Hz μVP-P fA/√Hz V+ 2.7 4.2 64 61 93 85 15 50 210 25 50 210 80 115 5 25 120 5 25 120 20 50 230 30 60 240 V pF pF dB dB dB dB mV mV mV mV mV mV ±330 ±750 ±330 ±1100 ±1100 ±1600 ±2 ±2 1 40 500 0.5 30 150 12 10 2.5 0.56 V+ V– ±5 ±5
MIN
TYP
l l l l
±330 ±750 ±330 ±1100 ±900 ±1350 ±2 ±2 1 0.5 ±5 ±5
ΔVOS/ΔT Input Offset Voltage Drift (Note 6) IB IOS en Input Bias Current (Notes 5, 7) Input Offset Current (Notes 5, 7) Input Noise Voltage Density Input Noise Voltage in CIN Input Noise Current Density (Note 8) Input Common Mode Range Input Capacitance Differential Mode Common Mode Common Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage, High (Referred to V+)
Guaranteed by 5V Test
●
f = 1kHz f = 10kHz 0.1Hz to 10Hz f = 1Hz
●
12 10 2.5 0.56 V– 2.7 4.2
f = 100kHz
CMRR PSRR VOUT
0V ≤ VCM ≤ 3V VS = 2.7V to 5.5V No Load ISOURCE = 1mA ISOURCE = 5mA No Load ISINK = 1mA ISINK = 5mA
● ● ● ● ● ● ● ●
64 63 93 90
80 115 5 25 120 5 25 120
Output Voltage, Low (Referred to V–)
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LTC6087/LTC6088 ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER AVOL ISC SR GBW Φ0 tS IS Large-Signal Voltage Gain Output Short-Circuit Current Slew Rate
The l denotes the specifications which apply over the full specified temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 3V, V– = 0V, VCM = 0.5V unless otherwise noted.
C SUFFIX CONDITIONS RLOAD = 10k, 0.5V ≤ VOUT ≤ 2.5V Source and Sink
● ●
H SUFFIX MAX MIN 500 30 25 18 10 8 TYP 3000 35 7.2 14 45 1 1.20 1.25 1 5.5 2.7 –120 2 0.8 0.8 6 2 0.5 0.1 0.5 1.05 1.05 0.2 1.20 1.35 1 5.5 MAX UNITS V/mV V/mV mA mA V/μs MHz MHz Deg μs mA mA μA V dB V V μs μs μA
MIN 500 300 25 21 10 9
TYP 3000 35 7.2 14 45 1 1.05 1.05 0.2
AV = 1
●
Gain Bandwidth Product (fTEST = 20kHz) RLOAD = 50k Phase Margin Settling Time 0.1% Supply Current (per Amplifier) Shutdown Current (per Amplifier) RL = 10k, CL = 45pF AV = 1 , VSTEP = 2V, AV = –1, RL = 1k No Load
●
Shutdown, VSHDNx ≤ 0.8V Guaranteed by the PSRR Test fS = 10kHz SHDNx High SHDNx Low VSHDNx = 0.8V to 2V VSHDNx = 2V to 0.8V VSHDNx = 0V
● ●
VS
Supply Voltage Range Channel Separation Shutdown Logic
2.7 –120 2 6 2
● ●
tON tOFF
Turn-On Time Turn-Off Time Leakage of SHDN Pin
●
0.1
The l denotes the specifications which apply over the full specified temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 5V, V– = 0V, VCM = 0.5V unless otherwise noted.
C SUFFIX SYMBOL PARAMETER VOS Offset Voltage (Note 5) CONDITIONS LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC MIN TYP MAX MIN ±330 ±750 ±330 ±1100 ±900 ±1350 ±2 ±2 1
●
H SUFFIX TYP MAX UNITS μV μV μV μV μV/°C μV/°C pA pA pA pA nV/√Hz nV/√Hz μVP-P fA/√Hz V+ 2.7 4.2 V pF pF ±330 ±750 ±330 ±1100 ±1100 ±1600 ±2 ±2 1 40 500 0.5 30 150 12 10 2.5 0.56 V+ V– ±5 ±5
l l l l
ΔVOS/ΔT Input Offset Voltage Drift (Note 6) IB IOS en Input Bias Current (Notes 5, 7) Input Offset Current (Notes 5, 7)
±5 ±5
0.5
●
Input Noise Voltage Density Input Noise Voltage
f = 1kHz f = 10kHz 0.1Hz to 10Hz f = 1Hz
●
12 10 2.5 0.56 V– 2.7 4.2
in CIN
Input Noise Current Density (Note 8) Input Common Mode Range Input Capacitance Differential Mode Common Mode
f = 100kHz
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LTC6087/LTC6088 ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CMRR PSRR VOUT Common Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage, High (Referred to V+)
The l denotes the specifications which apply over the full specified temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 5V, V– = 0V, VCM = 0.5V unless otherwise noted.
C SUFFIX CONDITIONS 0V ≤ VCM ≤ 5V VS = 2.7V to 5.5V No Load ISOURCE = 1mA ISOURCE = 5mA No Load ISINK = 1mA ISINK = 5mA RLOAD = 10k, 0.5V ≤ VOUT ≤ 4.5V Source and Sink
● ● ● ● ● ● ● ● ● ●
H SUFFIX MAX MIN 70 66 93 85 15 50 190 25 50 200 1000 50 28 22 10 8 TYP 84 115 5 20 110 5 20 110 6000 45 7.2 14 47 0.8 1.25 1.30 5 5.5 2.7 –120 3.5 1.2 1.2 6 2 1 0.4 1 1.05 1.05 2.3 1.25 1.40 5 5.5 20 50 210 30 60 220 MAX UNITS dB dB dB dB mV mV mV mV mV mV V/mV V/mV mA mA V/μs MHz MHz Deg μs mA mA μA V dB V V μs μs μA
MIN 70 68 93 90
TYP 84 115 5 20 110 5 20 110
Output Voltage, Low (Referred to V–)
AVOL ISC SR GBW Φ0 tS IS
Large-Signal Voltage Gain Output Short-Circuit Current Slew Rate
1000 500 28 25 10 9
6000 45 7.2 14 47 0.8 1.05 1.05 2.3
AV = 1
●
Gain Bandwidth Product (fTEST = 20kHz) RLOAD = 50k Phase Margin Settling Time 0.1% Supply Current (per Amplifier) Shutdown Current (per Amplifier) RL = 10k, CL = 45pF AV = 1 , VSTEP = 2V, AV = –1, RL = 1k No Load
●
Shutdown, VSHDNx ≤ 1.2V Guaranteed by the PSRR Test fS = 10kHz SHDNx High SHDNx Low VSHDNx = 1.2V to 3.5V VSHDNx = 3.5V to 1.2V VSHDNx = 0V
● ●
VS
Supply Voltage Range Channel Separation Shutdown Logic
2.7 –120 3.5 6 2
● ●
tON tOFF
Turn-On Time Turn-Off Time Leakage of SHDN Pin
●
0.4
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 the total output current. Note 3: The LTC6087C/LTC6088C are guaranteed functional over the operating temperature range of –40°C to 85°C. The LTC6087H/LTC6088H are guaranteed functional over the operating temperature range of –40°C to 125°C. Note 4: The LTC6087C/LTC6088C are guaranteed to meet specified performance from 0°C to 70°C. The LTC6087C/LTC6088C are designed, characterized and expected to meet specified performance from –40°C to 125ºC but are not tested or QA sampled at these temperatures.
The LTC6087H/LTC6088H are guaranteed to meet specified performance from –40°C to 125°C. Note 5: ESD (electrostatic discharge) sensitive device. ESD protection devices are used extensively internal to the LTC6087/LTC6088; however, high electrostatic discharge can damage or degrade the device. Use proper ESD handling precautions. Note 6: This parameter is not 100% tested. Note 7: This specification is limited by high speed automated test capability. See Typical Performance Characteristic curves for actual performance. Note 8: Current noise is calculated from: in = √2qIB, where q = 1.6 • 10–19 coulombs.
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LTC6087/LTC6088 TYPICAL PERFORMANCE CHARACTERISTICS
VOS Distribution
12 LTC6087MS8 VS = 5V 10 VCM = 0.5V TA = 25°C 8 VOS (mV) 6 4 2 0 –1 1.0 0.8 0.6 0.4 0.2 0 –0.2 –0.4 –0.6 V = 5V S –0.8 TA = 25°C REPRESENTATIVE PARTS –1.0 0 0.5 1 1.5 2 2.5 3 VCM (V) PERCENT OF UNITS (%)
VOS vs VCM
22 20 18 16 14 12 10 8 6 4 2 3.5 4 4.5 5 0
VOS Drift Distribution
LTC6087MS8 VS = 5V VCM = 2.5V TA = –40°C TO 125°C
PERCENTAGE OF UNITS (%)
–0.7 –0.4 –0.1 0.2 VOS (mV)
0.5
0.8
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–2
–1.2
–0.4 0.4 1.2 2.0 DISTRIBUTION (μV/°C)
2.8
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Input Bias Current vs Common Mode Voltage
10000 1000 INPUT BIAS CURRENT (pA) 100 TA = 85°C 10 TA = 25°C 1 0.1 0.01 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 COMMON MODE VOLTAGE (V) 5 VS = 5V TA = 125°C INPUT NOISE VOLTAGE (nV/√Hz) 100 90 80 70 60 50 40 30 20 10 0
Input Noise Voltage vs Frequency
VS = 5V VCM = 2.5V TA = 25°C
0.1Hz to 10Hz Output Voltage Noise
VS = 5V VCM = 2.5V
INPUT NOISE VOLTAGE (1μV/DIV)
10
100
1k 10k FREQUENCY (Hz)
100k
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TIME (1s/DIV)
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Input Noise Current vs Frequency
500 5.0
Output Voltage Swing vs Load Current
VS = 5V 4.5 VCM = 2.5V OUTPUT VOLTAGE SWING (V) 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 TA = 125°C TA = 25°C TA = –55°C SINK SUPPLY CURRENT (mA) 100
60878 G08
Supply Current vs Supply Voltage
1.2 PER AMPLIFIER VCM = 0.5V 1.0 TA = 25°C
NOISE CURRENT (fA/√Hz)
400
SOURCE
0.8 0.6 0.4 0.2 0
300
200
100
0 1 10 100 1000 FREQUENCY (Hz) 10000 100000
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0 0.1
1 10 LOAD CURRENT (mA)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 SUPPLY VOLTAGE (V)
69878 G09
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LTC6087/LTC6088 TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current vs Temperature
1.5 1.4 1.3 SUPPLY CURRENT (mA) 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C)
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Open-Loop Gain vs Frequency
80 70 60 PHASE CL = 5pF 100 RL = 1k VCM = VS/2 80 TA = 25°C 60 PHASE (DEG) 40 20 0 –20 –40 VS = 5V VS = 3V 100k 1M 10M FREQUENCY (Hz) –60 –80 100M
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CMRR vs Frequency
120 110 100 90 80 70 CMRR (dB) 60 50 40 30 20 10 0 –10 10k 100k 1M 10M FREQUENCY (Hz) 100M
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PER AMPLIFIER VCM = 0.5V VS = 5V GAIN (dB) VS = 3V
VS = 5V VCM = 2.5V RL = 1k TA = 25°C
50 40 30 20 10 0 –10 –20 10k GAIN
PSRR vs Frequency
100 90 80 70 PSRR (dB) 60 50 40 30 20 10 0 –10 1k 10k 100k 1M FREQUENCY (Hz) 10M 100M
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Output Impedance vs Frequency
VS = 5V VCM = 2.5V TA = 25°C 1000 VS = 5V VCM = 2.5V 100 TA = 25°C 10 AV = 10 1 0.1 0.01 0.001 10k 10M 100k 1M FREQUENCY (Hz) 100M
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Small-Signal Response
OUTPUT IMPEDANCE (Ω)
POSITIVE SUPPLY
NEGATIVE SUPPLY
AV = 2 AV = 1
100mV/DIV
VS = 5V AV = 1 RL = ∞
200ns/DIV
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Small-Signal Response
Large-Signal Response
Large-Signal Response
100mV/DIV
1V/DIV
VS = 5V AV = 1 RL = ∞ CL = 33pF
200ns/DIV
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VS = 5V AV = 1 RL = ∞
2μs/DIV
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1V/DIV
VS = 5V AV = –1 RL = 1k
1μs/DIV
60878 G18
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LTC6087/LTC6088 TYPICAL PERFORMANCE CHARACTERISTICS
Disabled Output Impedance vs Frequency
1000000 100000 OUTPUT IMPEDANCE (kΩ) 10000 OVERSHOOT (%) 1000 100 10 1 0.1 100 VS = 5V VCM = 1V AV = 1 TA = 25°C 80
Overshoot vs Capacitive Load
VS = 5V 70 VCM = 2.5V AV = 1 60 50 RS = 50Ω 40 30 40
Overshoot vs Capacitive Load
VS = 5V 35 VCM = 2.5V AV = –1 30 OVERSHOOT (%) 25
1k
RS = 10Ω
30pF
RS = 10Ω
RS CL
15 10
10 1k 10k 100k FREQUENCY (Hz) 1M 10M
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0 10 100 CAPACITIVE LOAD (pF) 1000
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Channel Separation vs Frequency
–90 –95 CHANNEL SEPARATON (dB) –100 –105 –110 –115 –120 –125 –130 0.01 0.1 1 10 FREQUENCY (MHz) 100
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Total Harmonic Distortion + Noise vs Frequency
1 0.1 VS = 3V VCM = 1.5V RL = 10k THD + NOISE (%)
VS = 5V VCM = 2.5V TA = 25°C THD + NOISE (%) 0.1
AV = 1, VIN = 2VP-P AV = 1, VIN = 1VP-P 0.01 AV = –2, VIN = 1VP-P AV = 2, VIN = 1VP-P
0.001 0.01
0.1
1 10 FREQUENCY (kHz)
Total Harmonic Distortion + Noise vs Output Voltage
0.1 VS = 3V AT 20kHz THD + NOISE (%) 0.01 VS = 3V AT 1kHz 0.1
THD + NOISE (%)
VS = 5V AT 20kHz
VS = 5V AT 1kHz 0.001 RL = 10k VCM = VS/2 AV = 1 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 OUTPUT VOLTAGE (VP-P)
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0.0001
8
+ –
20
RS CL
5 0 10 100 CAPACITIVE LOAD (pF) 1000
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Total Harmonic Distortion + Noise vs Frequency
VS = 5V VCM = 2.5V RL = 10k
0.01
AV = 2, VIN = 1VP-P AV = –2, VIN = 1VP-P
AV = 1, VIN = 1VP-P AV = 1, VIN = 2VP-P 100
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0.001 0.01
Total Harmonic Distortion + Noise vs Load Resistance
AV = 1 VCM = VS/2 AT 1kHz VS = 3V, VIN = 1VP-P 0.01
VS = 5V, VIN = 2VP-P
0.001
0.0001 0.1 1 10 LOAD RESISTANCE TO GROUND (kΩ) 100
+ –
0.1
20
1k
RS = 50Ω
1 10 FREQUENCY (kHz)
100
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LTC6087/LTC6088 PIN FUNCTIONS
OUT: Amplifier Output. –IN: Inverting Input. +IN: Noninverting Input. V+: Positive Supply. V–: Negative Supply. SHDNA: Shutdown Pin of Amplifier A, active low and only available with the LTC 6087DD. An internal current source pulls the pin to V+ when floating. SHDNB: Shutdown Pin of Amplifier B, active low and only available with the LTC 6087DD. An internal current source pulls the pin to V+ when floating. NC: Not internally connected Exposed Pad: Connected to V–.
APPLICATIONS INFORMATION
Rail-to-Rail Input The input stage of LTC6087/LTC6088 combines both PMOS and NMOS differential pairs, extending its input common mode voltage 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. Achieving Low Input Bias Current The DD and DHC packages are leadless and make contact to the PCB beneath the package. Solder flux used during the attachment of the part to the PCB can create leakage current paths and can degrade the input bias current performance of the part. All inputs are susceptible because the backside paddle is connected to V– internally. As the input voltage or V– changes, a leakage path can be formed and alter the observed input bias current. For lowest bias current use the LTC6087/LTC6088 in the leaded MSOP/GN package. With fine PCB design rules, you can also provide a guard ring around the inputs. For example, in high source impedance applications such as pH probes, photo diodes, strain gauges, et cetera, the low input bias current of these parts requires a clean board layout to minimize additional leakage current into a high impedance signal node. A mere 100GΩ of PC board resistance between a 5V supply trace and input trace near ground potential adds 50pA of leakage current. This leakage is far greater than the bias current of the operational amplifier. A guard ring around the high impedance input traces driven by a low impedance source equal to the input voltage prevents such leakage problems. The guard ring should extend as far as necessary to shield the high impedance signal from any and all leakage paths. Figure 1 shows the use of a guard ring in a unity-gain configuration. In this case the guard ring is connected to the output and is shielding the high impedance noninverting input from V–. Figure 2 shows the inverting gain configuration.
OUT R OUT LTC6087 IN– VIN IN+ LTC6087
NO SOLDER MASK OVER THE GUARD RING R
NO LEAKAGE CURRENT
R IN–
IN+ LEAKAGE CURRENT GUARD RING V–
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GND V–
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Figure 1. Sample Layout. Unity-Gain Configuration. Using Guard Ring to Shield High Impedance Input from Board Leakage
Figure 2. Sample Layout. Inverting Gain Configuration. Using Guard Ring to Shield High Impedance Input from Board Leakage
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LTC6087/LTC6088 APPLICATIONS INFORMATION
Rail-to-Rail Output The output stage of the LTC6087/LTC6088 swings within 30mV of the supply rails when driving high impedance loads, in other words when no DC load current is present. See the Typical Performance Characteristics for curves of output swing versus load current. The class AB design of the output stage enables the op amp to supply load currents which are much greater than the quiescent supply current. For example, the room temperature short circuit current is typically 45mA. Capacitive Load LTC6087/LTC6088 can drive capacitive load up to 100pF in unity gain. The capacitive load driving capability increases as the amplifier is used in higher gain configurations. A small series resistance between the output and the load further increases the amount of capacitance the amplifier can drive. SHDN Pins Pins 5 and 6 are used for power shutdown when the LTC6087 is 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 5μA current. This feature allows the part to be used in muxed output applications as shown in Figure 3. ESD The LTC6087/LTC6088 has reverse-biased ESD protection diodes on all inputs and outputs as shown in the Simplified Schematic. If these pins are forced beyond either supply, unlimited current will flow through these diodes. If the current is transient and limited to one hundred milliamps or less, no damage to the device will occur. The amplifier input bias current is the leakage current of these ESD diodes. This leakage is a function of the temperature and common mode voltage of the amplifier, as shown in the Typical Performance Characteristics. Noise In the frequency region above 1kHz, the LTC6087/LTC6088 shows good noise voltage performance. In this region, noise can be dominated by the total source resistance of the particular application. Specifically, these amplifiers exhibit the noise of a 10k resistor, meaning it is desirable to keep the source and feedback resistance at or below this value, i.e., RS + RG||RFB ≤ 10k. Above this total source impedance, the noise voltage is dominated by the resistor. At low frequency, noise current can be estimated from the expression in = √2qIB, where q = 1.6 • 10–19 coulombs. Equating √4kTRΔf and R√2qIBΔf shows that for source resistor below 50GΩ the amplifier noise is dominated by the source resistance. Noise current rises with frequency. See the curve Noise Current vs Frequency in the Typical Performance Characteristics section.
10k 5V SEL SHDN B FAIRCHILD NC7SZ04 OR EQUIVALENT 10k 5V 5V 10k
+
10k INA A LTC6087 (DD PACKAGE) SHDN A 10k
–
10k 5V 10k 10k INB
+
B
10pF
OUT
–
10pF
SEL = 5V, OUT = –INA SEL = 0V, OUT = –1NB
60878 F03
Figure 3. Inverting Amplifier with Muxed Output
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10
LTC6087/LTC6088 SIMPLIFIED SCHEMATIC
V+ R1 M10 M11 C1 R2 M8 I1 I2 V– +IN D3 D6 V– –IN D5 BIAS GENERATION D1 NOTE: SHDN IS ONLY AVAILABLE V– IN THE DFN10 PACKAGE V– M3 M4 R3 R4
60878 SS
1μA
V+ D4 VBIAS M5
–
A1
+
V+ D7
V+ M1 M2 M6 M7
OUTPUT CONTROL D8 V– A2
OUT
V+ D2 SHDN
V–
–
+
C2 M9
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11
LTC6087/LTC6088 PACKAGE DESCRIPTION
MS8 Package 8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660 Rev F)
0.889 (.035
0.127 .005)
5.23 (.206) MIN
3.20 – 3.45 (.126 – .136)
0.42 0.038 (.0165 .0015) TYP
0.65 (.0256) BSC
3.00 0.102 (.118 .004) (NOTE 3)
8
7 65
0.52 (.0205) REF
RECOMMENDED SOLDER PAD LAYOUT
DETAIL “A” 0 – 6 TYP 4.90 0.152 (.193 .006) 3.00 0.102 (.118 .004) (NOTE 4)
0.254 (.010) GAUGE PLANE
1 0.53 0.152 (.021 .006) DETAIL “A” 0.18 (.007) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 1.10 (.043) MAX
23
4 0.86 (.034) REF
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
0.65 (.0256) BSC
0.1016 (.004
0.0508 .002)
MSOP (MS8) 0307 REV F
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12
LTC6087/LTC6088 PACKAGE DESCRIPTION
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 0.38 10 0.10
3.00 0.10 (4 SIDES) PIN 1 TOP MARK (SEE NOTE 6)
1.65 0.10 (2 SIDES)
(DD) DFN 1103
5 0.200 REF 0.75 0.05 2.38 0.10 (2 SIDES)
1 0.25 0.05 0.50 BSC
0.00 – 0.05
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
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13
LTC6087/LTC6088 PACKAGE DESCRIPTION
GN Package 16-Lead Plastic SSOP (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1641)
.045 .005 .189 – .196* (4.801 – 4.978) 16 15 14 13 12 11 10 9
.009 (0.229) REF
.254 MIN
.150 – .165 .229 – .244 (5.817 – 6.198) .150 – .157** (3.810 – 3.988)
.0165
.0015
.0250 BSC 1 .015 .004 (0.38 0.10)
45
RECOMMENDED SOLDER PAD LAYOUT 23 4 56 7 8 .004 – .0098 (0.102 – 0.249)
.0532 – .0688 (1.35 – 1.75)
.007 – .0098 (0.178 – 0.249)
0 – 8 TYP
.016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 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
.008 – .012 (0.203 – 0.305) TYP
.0250 (0.635) BSC
GN16 (SSOP) 0204
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14
LTC6087/LTC6088 PACKAGE DESCRIPTION
DHC Package 16-Lead Plastic DFN (5mm × 3mm)
(Reference LTC DWG # 05-08-1706)
0.65
0.05
3.50
0.05 2.20
1.65 0.05 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 R = 0.20 TYP 9 16 0.40 0.10
5.00 0.10 (2 SIDES)
3.00 0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6)
1.65 0.10 (2 SIDES) PIN 1 NOTCH
(DHC16) DFN 1103
8 0.200 REF 0.75 0.05 4.40 0.10 (2 SIDES)
1 0.25 0.05 0.50 BSC
0.00 – 0.05 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
BOTTOM VIEW—EXPOSED PAD
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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.
15
LTC6087/LTC6088 TYPICAL APPLICATIONS
Negative-Going and Positive-Going Photodiode TIAs on ±5V Supplies
CF 2pF RF 100k 1N4148 IPD VOUT 0V – IPD • RF PHOTODIODE ~3pF –5V NOTE: DIFFERENT DEVICES. NOT THE SAME LTC6087 1.5k –5V
60878 TA02
5V 1.5k 5V PHOTODIODE ~3pF IPD 5V
+
1/2 LTC6087
1/2 LTC6087
–
RF –5V 100k CF 2pF
Almost Rail-to-Rail (0.3V to VCC) Gain-of-30 Current Sense Amplifier –
VSENSE ISENSE RSENSE
LOAD
+
100 1%
VS GAIN OF 2 STAGE VCC
+
RCOMP 10k 1/2 LTC6087
GAIN OF 15 STAGE 2N7002
–
CCOMP 1nF
+
200 1% 1/2 LTC6087 OUT
–
FULL-SCALE VSENSE = 100mV (3V OUT). FOR SMALL SIGNALS, INPUT OPERATION IS RAIL-TO-RAIL (VS = 5mV to VCC). FOR FULL SCALE, INPUT OPERATION IS 0.3V TO RAIL. WORST-CASE INPUT OFFSET VOLTAGE = 1.8mV. 10k 1%
60878 TA03
140k 1%
RELATED PARTS
PART NUMBER LTC2051/LTC2052 LTC6078/LTC6079 LTC6240 LTC6241/LTC6242 LTC6244 DESCRIPTION Dual/Quad Zero-Drift Op Amps Single Low Noise Rail-to-Rail Output Op Amp Dual/Quad Low Noise Rail-to-Rail Output Op Amps Dual 50MHz Rail-to-Rail Op Amps COMMENTS 3μV VOS(MAX), 30nV/°C VOS Drift (MAX) 7nV/√Hz Noise, 1pA IBIAS(MAX), 10V/μs Slew Rate 7nV/√Hz Noise, 0.2pA IBIAS, 18MHz Gain Bandwidth 100μV VOS(MAX), 1pA IBIAS, 40V/μs Slew Rate Dual/Quad Micropower Precision Rail-to-Rail Op Amps 25μV VOS(MAX), 0.7μV/°C VOS Drift (MAX), 1pA IBIAS(MAX)
16 Linear Technology Corporation
(408) 432-1900 ● FAX: (408) 434-0507
●
1630 McCarthy Blvd., Milpitas, CA 95035-7417
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2007
+
–
VOUT 0V + IPD • RF 1N4148
60878fb LT 0608 REV B • PRINTED IN USA