LTC6087/LTC6088 Dual/Quad 14MHz, Rail-to-Rail CMOS Amplifiers FEATURES DESCRIPTION n 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. n n n n n n n n n n n 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) 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. APPLICATIONS n n n n n Portable Test Equipment Medical Equipment Audio Data Acquisition High Impedance Transducer Amplifier L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION LTC6087 Input Bias Current vs Temperature Single Supply Shock/Vibration Sensor Amplifier VS VS 100k + 100k MURATA SHOCK SENSOR PKGS-00MX1 520pF, 0.57pC/g www.murata.com 0.1μF 1/2 LTC6087 + 1/2 LTC6087 – – 1k 1% 100M 100pF 100k 1% VOUT 570mV/g 16Hz TO 10kHz VS = 2.7V TO 5.5V INPUT BIAS CURRENT (pA) 1000 VS = 5V VCM = 2.5V 100 10 60878 TA01a 1 25 40 55 70 85 100 TEMPERATURE (°C) 115 130 60878 TA01b 60878fb 1 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 B V+ OUTB –INB +INB MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 200°C/W OUTA 1 –INA 2 +INA 3 V– 4 SHDNA 5 +INA 2 3 V+ 4 +INB 5 –INB 6 OUTB 7 NC 8 – +A D 15 –IND 14 +IND 13 + –B + C– 8 –INB B 7 +INB 6 SHDNB TOP VIEW 16 OUTD + – –INA 1 9 OUTB 11 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 OUTA 10 V+ – +A V– 12 +INC 11 –INC 10 OUTC 9 NC GN PACKAGE 16-LEAD PLASTIC SSOP NARROW TJMAX = 150°C, θJA = 110°C/W OUTA 1 16 OUTD –INA 2 +INA 3 V+ 4 +INB 5 –INB 6 OUTB 7 10 OUTC NC 8 9 – +A + – – +A 8 7 6 5 + – 1 2 3 4 + – TOP VIEW OUTA –INA +INA V– D 14 +IND 13 V– 17 + –B 15 –IND + C– 12 +INC 11 –INC NC 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 60878fb 2 LTC6087/LTC6088 ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC6087CDD#PBF LTC6087HDD#PBF LTC6087CMS8#PBF LTC6087HMS8#PBF LTC6088CDHC#PBF LTC6088HDHC#PBF LTC6088CGN#PBF LTC6088HGN#PBF LTC6087CDD#TRPBF LTC6087HDD#TRPBF LTC6087CMS8#TRPBF LTC6087HMS8#TRPBF LTC6088CDHC#TRPBF LTC6088HDHC#TRPBF LTC6088CGN#TRPBF LTC6088HGN#TRPBF LCTX LCTX LTCTY LTCTY 6088 6088 6088 6088H 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 –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/ ELECTRICAL CHARACTERISTICS 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 MIN LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC l l ΔVOS/ΔT Input Offset Voltage Drift (Note 6) LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC l l IB Guaranteed by 5V Test VOS IOS en in Offset Voltage (Note 5) CONDITIONS Input Bias Current (Notes 5, 7) Input Offset Current (Notes 5, 7) CMRR PSRR VOUT MAX MIN ±330 ±750 ±330 ±1100 ±900 ±1350 ±2 ±2 ±5 ±5 TYP MAX UNITS ±330 ±750 ±330 ±1100 ±1100 ±1600 μV μV μV μV ±2 ±2 1 ● 0.5 ● ±5 ±5 μV/°C μV/°C 500 pA pA 150 pA pA 1 40 Guaranteed by 5V Test 0.5 30 Input Noise Voltage Density f = 1kHz f = 10kHz 12 10 12 10 nV/√Hz nV/√Hz Input Noise Voltage 0.1Hz to 10Hz 2.5 2.5 μVP-P Input Noise Current Density (Note 8) f = 1Hz Input Capacitance Differential Mode Common Mode f = 100kHz Common Mode Rejection Ratio 0V ≤ VCM ≤ 3V Power Supply Rejection Ratio 0.56 ● Input Common Mode Range CIN TYP H SUFFIX V– 0.56 V+ V– 2.7 4.2 VS = 2.7V to 5.5V fA/√Hz V+ V 2.7 4.2 pF pF 64 63 80 64 61 80 ● dB dB 93 90 115 93 85 115 ● dB dB Output Voltage, High (Referred to V+) No Load ISOURCE = 1mA ISOURCE = 5mA ● ● ● 5 25 120 15 50 210 5 25 120 20 50 230 mV mV mV Output Voltage, Low (Referred to V–) No Load ISINK = 1mA ISINK = 5mA ● ● ● 5 25 120 25 50 210 5 25 120 30 60 240 mV mV mV 60878fb 3 LTC6087/LTC6088 ELECTRICAL CHARACTERISTICS 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 CONDITIONS AVOL Large-Signal Voltage Gain RLOAD = 10k, 0.5V ≤ VOUT ≤ 2.5V ISC Output Short-Circuit Current SR Slew Rate GBW Gain Bandwidth Product (fTEST = 20kHz) RLOAD = 50k MIN TYP ● 500 300 ● 25 21 Source and Sink AV = 1 H SUFFIX MAX MIN TYP 3000 500 30 3000 35 25 18 35 mA mA 7.2 V/μs 14 MHz MHz 7.2 ● 10 9 14 10 8 MAX UNITS V/mV V/mV Φ0 Phase Margin RL = 10k, CL = 45pF, AV = 1 45 45 Deg tS Settling Time 0.1% VSTEP = 2V, AV = –1, RL = 1k 1 1 μs IS Supply Current (per Amplifier) No Load ● 1.05 1.05 1.20 1.25 1.05 1.05 1.20 1.35 mA mA Shutdown, VSHDNx ≤ 0.8V ● 0.2 1 0.2 1 μA Supply Voltage Range Guaranteed by the PSRR Test ● Channel Separation fS = 10kHz Shutdown Logic SHDNx High SHDNx Low Shutdown Current (per Amplifier) VS 2.7 5.5 2.7 –120 ● ● 5.5 V –120 2 dB 2 0.8 V V 0.8 tON Turn-On Time VSHDNx = 0.8V to 2V 6 6 μs tOFF Turn-Off Time VSHDNx = 2V to 0.8V 2 2 μs Leakage of SHDN Pin VSHDNx = 0V ● 0.1 0.5 0.1 0.5 μA 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) ΔVOS/ΔT Input Offset Voltage Drift (Note 6) IB IOS en in CONDITIONS LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC l l LTC6087MS8, LTC6088GN LTC6087DD, LTC6088DHC l l TYP H SUFFIX MAX MIN ±330 ±750 ±330 ±1100 ±900 ±1350 ±2 ±2 Input Bias Current (Notes 5, 7) ±5 ±5 TYP MAX UNITS ±330 ±750 ±330 ±1100 ±1100 ±1600 μV μV μV μV ±2 ±2 1 ● 0.5 ● ±5 ±5 μV/°C μV/°C 500 pA pA 150 pA pA 1 40 Input Offset Current (Notes 5, 7) 0.5 30 Input Noise Voltage Density f = 1kHz f = 10kHz 12 10 12 10 nV/√Hz nV/√Hz Input Noise Voltage 0.1Hz to 10Hz 2.5 2.5 μVP-P Input Noise Current Density (Note 8) f = 1Hz Input Capacitance Differential Mode Common Mode 0.56 ● Input Common Mode Range CIN MIN V– 0.56 V+ V– fA/√Hz V+ V f = 100kHz 2.7 4.2 2.7 4.2 pF pF 60878fb 4 LTC6087/LTC6088 ELECTRICAL CHARACTERISTICS 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 H SUFFIX SYMBOL PARAMETER CONDITIONS MIN TYP MIN TYP CMRR 0V ≤ VCM ≤ 5V 84 70 66 84 ● 70 68 dB dB 93 90 115 93 85 115 ● dB dB PSRR Common Mode Rejection Ratio Power Supply Rejection Ratio VS = 2.7V to 5.5V MAX MAX UNITS Output Voltage, High (Referred to V+) No Load ISOURCE = 1mA ISOURCE = 5mA ● ● ● 5 20 110 15 50 190 5 20 110 20 50 210 mV mV mV Output Voltage, Low (Referred to V–) No Load ISINK = 1mA ISINK = 5mA ● ● ● 5 20 110 25 50 200 5 20 110 30 60 220 mV mV mV AVOL Large-Signal Voltage Gain RLOAD = 10k, 0.5V ≤ VOUT ≤ 4.5V ISC Output Short-Circuit Current SR Slew Rate GBW Gain Bandwidth Product (fTEST = 20kHz) RLOAD = 50k VOUT 1000 500 6000 1000 50 6000 ● 28 25 45 28 22 45 ● mA mA 7.2 V/μs 14 MHz MHz 47 Deg Source and Sink AV = 1 7.2 ● 10 9 14 10 8 V/mV V/mV Φ0 Phase Margin RL = 10k, CL = 45pF, AV = 1 tS Settling Time 0.1% VSTEP = 2V, AV = –1, RL = 1k 0.8 IS Supply Current (per Amplifier) No Load ● 1.05 1.05 1.25 1.30 1.05 1.05 1.25 1.40 mA mA Shutdown Current (per Amplifier) Shutdown, VSHDNx ≤ 1.2V ● 2.3 5 2.3 5 μA Supply Voltage Range Guaranteed by the PSRR Test ● 5.5 V Channel Separation fS = 10kHz Shutdown Logic SHDNx High SHDNx Low VS tON Turn-On Time VSHDNx = 1.2V to 3.5V tOFF Turn-Off Time VSHDNx = 3.5V to 1.2V Leakage of SHDN Pin VSHDNx = 0V 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. 47 2.7 0.8 5.5 2.7 –120 ● ● ● μs –120 3.5 dB 3.5 1.2 1.2 V V 6 6 μs 2 2 μs 0.4 1 0.4 1 μA 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. 60878fb 5 LTC6087/LTC6088 TYPICAL PERFORMANCE CHARACTERISTICS VOS Distribution VOS vs VCM LTC6087MS8 VS = 5V 10 VCM = 0.5V TA = 25°C 22 0.8 20 0.6 PERCENT OF UNITS (%) 0.4 VOS (mV) 8 6 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) 2 0 –1 –0.7 –0.4 –0.1 0.2 VOS (mV) 0.5 0.8 14 12 10 8 6 2 3.5 4 4.5 0 5 VS = 5V 100 TA = 85°C 10 TA = 25°C 1 0.1 –1.2 –0.4 0.4 1.2 2.0 DISTRIBUTION (μV/°C) 80 2.8 60878 G03 VS = 5V VCM = 2.5V TA = 25°C 90 TA = 125°C –2 0.1Hz to 10Hz Output Voltage Noise Input Noise Voltage vs Frequency 100 INPUT NOISE VOLTAGE (nV/√Hz) INPUT BIAS CURRENT (pA) 16 60878 G02 Input Bias Current vs Common Mode Voltage 1000 LTC6087MS8 VS = 5V VCM = 2.5V TA = –40°C TO 125°C 4 60878 G01 10000 18 INPUT NOISE VOLTAGE (1μV/DIV) PERCENTAGE OF UNITS (%) VOS Drift Distribution 1.0 12 70 60 50 40 30 20 VS = 5V VCM = 2.5V 10 0.01 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 COMMON MODE VOLTAGE (V) 5 10 100 1k 10k FREQUENCY (Hz) 60878 G05 60878 G06 60878 G07 Output Voltage Swing vs Load Current Input Noise Current vs Frequency Supply Current vs Supply Voltage 5.0 500 1.2 PER AMPLIFIER VCM = 0.5V 1.0 TA = 25°C VS = 5V 4.5 VCM = 2.5V 300 200 100 4.0 3.0 2.5 2.0 1.5 1.0 0.5 0 1 10 100 1000 FREQUENCY (Hz) 10000 100000 60878 G04 SOURCE 3.5 SUPPLY CURRENT (mA) 400 OUTPUT VOLTAGE SWING (V) NOISE CURRENT (fA/√Hz) TIME (1s/DIV) 100k 0 0.1 TA = 125°C TA = 25°C TA = –55°C SINK 0.8 0.6 0.4 0.2 0 1 10 LOAD CURRENT (mA) 100 60878 G08 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 SUPPLY VOLTAGE (V) 69878 G09 60878fb 6 LTC6087/LTC6088 TYPICAL PERFORMANCE CHARACTERISTICS Open-Loop Gain vs Frequency 80 PER AMPLIFIER VCM = 0.5V 1.4 60 50 VS = 5V 1.2 PHASE GAIN (dB) 1.1 VS = 3V 40 40 GAIN 30 20 20 0 0.8 10 –20 0.7 0 –40 0.6 –10 0.5 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) –20 10k 0.9 VS = 5V VS = 3V 100k 80 1M 10M FREQUENCY (Hz) VS = 5V VCM = 2.5V TA = 25°C 60 NEGATIVE SUPPLY 40 30 20 10 40 30 20 10 0 –10 10k 10k 100k 1M FREQUENCY (Hz) 10M 10 AV = 10 1 AV = 2 AV = 1 0.1 VS = 5V AV = 1 RL = ∞ 10k 100M 10M 100k 1M FREQUENCY (Hz) Small-Signal Response Large-Signal Response 60878 G16 60878 G15 100M Large-Signal Response 1V/DIV 1V/DIV 200ns/DIV 200ns/DIV 60878 G14 60878 G13 VS = 5V AV = 1 RL = ∞ CL = 33pF 100M VS = 5V VCM = 2.5V 100 TA = 25°C 0.001 1k 1M 10M FREQUENCY (Hz) Small-Signal Response 0.01 –10 100k 60878 G12 0 100mV/DIV PSRR (dB) 50 Output Impedance vs Frequency 70 50 –80 100M 60 1000 OUTPUT IMPEDANCE (Ω) POSITIVE SUPPLY 70 60878 G11 PSRR vs Frequency 90 80 –60 60878 G10 100 90 100mV/DIV 1.0 VS = 5V VCM = 2.5V RL = 1k TA = 25°C 100 PHASE (DEG) SUPPLY CURRENT (mA) CL = 5pF 100 RL = 1k VCM = VS/2 80 TA = 25°C 60 70 1.3 CMRR vs Frequency 110 120 CMRR (dB) Supply Current vs Temperature 1.5 VS = 5V AV = 1 RL = ∞ 2μs/DIV 60878 G17 VS = 5V AV = –1 RL = 1k 1μs/DIV 60878 G18 60878fb 7 LTC6087/LTC6088 TYPICAL PERFORMANCE CHARACTERISTICS Disabled Output Impedance vs Frequency VS = 5V VCM = 1V AV = 1 TA = 25°C 10000 1000 100 40 VS = 5V 70 VCM = 2.5V AV = 1 60 OVERSHOOT (%) OUTPUT IMPEDANCE (kΩ) 100000 10 1 RS = 10Ω RS = 50Ω 40 30 – + 10k 100k FREQUENCY (Hz) 1M RS CL 5 0 100 CAPACITIVE LOAD (pF) 100 CAPACITIVE LOAD (pF) 10 1000 Total Harmonic Distortion + Noise vs Frequency 1 VS = 5V VCM = 2.5V TA = 25°C 1000 60878 G22 60878 G21 Total Harmonic Distortion + Noise vs Frequency 0.1 VS = 3V VCM = 1.5V RL = 10k VS = 5V VCM = 2.5V RL = 10k –105 –110 –115 THD + NOISE (%) –100 THD + NOISE (%) CHANNEL SEPARATON (dB) – + RS = 50Ω CL 10 Channel Separation vs Frequency –95 1k 15 0 10M RS = 10Ω 1k 20 10 60878 G20 –90 30pF 25 RS 10 1k VS = 5V 35 VCM = 2.5V AV = –1 30 50 20 0.1 100 Overshoot vs Capacitive Load Overshoot vs Capacitive Load 80 OVERSHOOT (%) 1000000 0.1 AV = 1, VIN = 2VP-P AV = 1, VIN = 1VP-P 0.01 0.01 –120 AV = 1, VIN = 1VP-P AV = –2, VIN = 1VP-P –125 –130 0.01 AV = 2, VIN = 1VP-P AV = –2, VIN = 1VP-P AV = 1, VIN = 2VP-P AV = 2, VIN = 1VP-P 0.1 1 10 FREQUENCY (MHz) 100 0.001 0.01 0.1 1 10 FREQUENCY (kHz) 60878 G23 100 0.1 VS = 5V AT 20kHz VS = 5V AT 1kHz 60878 G25 AV = 1 VCM = VS/2 AT 1kHz 0.01 VS = 5V, VIN = 2VP-P 0.001 0.001 0.0001 100 VS = 3V, VIN = 1VP-P THD + NOISE (%) THD + NOISE (%) 0.01 1 10 FREQUENCY (kHz) Total Harmonic Distortion + Noise vs Load Resistance 0.1 VS = 3V AT 1kHz 0.1 60878 G24 Total Harmonic Distortion + Noise vs Output Voltage VS = 3V AT 20kHz 0.001 0.01 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) 60878 G26 0.0001 0.1 1 10 LOAD RESISTANCE TO GROUND (kΩ) 100 60878 G27 60878fb 8 LTC6087/LTC6088 PIN FUNCTIONS 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. OUT: Amplifier Output. –IN: Inverting Input. +IN: Noninverting Input. 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. V+: Positive Supply. V–: Negative Supply. NC: Not internally connected Exposed Pad: Connected to V–. APPLICATIONS INFORMATION package. With fine PCB design rules, you can also provide a guard ring around the inputs. 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 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 NO SOLDER MASK OVER THE GUARD RING NO LEAKAGE CURRENT OUT LTC6087 IN– LTC6087 R IN– VIN R IN+ IN+ LEAKAGE CURRENT GND GUARD RING V– V– 60878 F01 Figure 1. Sample Layout. Unity-Gain Configuration. Using Guard Ring to Shield High Impedance Input from Board Leakage 60878 F02 Figure 2. Sample Layout. Inverting Gain Configuration. Using Guard Ring to Shield High Impedance Input from Board Leakage 60878fb 9 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. 10k 10k 5V 5V + LTC6087 (DD PACKAGE) A 10k – INA SHDN A 10k 10k 10k OUT 10pF + 5V B 10k – INB 10pF Capacitive Load SEL = 5V, OUT = –INA SEL = 0V, OUT = –1NB 10k 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. 5V SEL SHDN B FAIRCHILD NC7SZ04 OR EQUIVALENT 60878 F03 Figure 3. Inverting Amplifier with Muxed Output SHDN Pins Noise 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. 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. 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. 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. 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. 60878fb 10 LTC6087/LTC6088 SIMPLIFIED SCHEMATIC V+ R1 M10 R2 M11 M8 I1 1μA V– C1 + – V+ I2 A1 VBIAS D4 M5 V+ +IN V+ D7 V+ D3 OUTPUT CONTROL M6 M7 M1 M2 D8 –IN V– D5 D2 BIAS GENERATION SHDN A2 + – V– C2 D1 NOTE: SHDN IS ONLY AVAILABLE V– IN THE DFN10 PACKAGE V– OUT D6 V– M3 M9 M4 R3 R4 60878 SS 60878fb 11 LTC6087/LTC6088 PACKAGE DESCRIPTION MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660 Rev F) 0.889 p 0.127 (.035 p .005) 5.23 (.206) MIN 3.20 – 3.45 (.126 – .136) 0.42 p 0.038 (.0165 p .0015) TYP 3.00 p 0.102 (.118 p .004) (NOTE 3) 0.65 (.0256) BSC 8 7 6 5 0.52 (.0205) REF RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) 3.00 p 0.102 (.118 p .004) (NOTE 4) 4.90 p 0.152 (.193 p .006) DETAIL “A” 0o – 6o TYP GAUGE PLANE 1 0.53 p 0.152 (.021 p .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 0.1016 p 0.0508 (.004 p .002) MSOP (MS8) 0307 REV F 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 60878fb 12 LTC6087/LTC6088 PACKAGE DESCRIPTION DD Package 10-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1699) 0.675 p 0.05 3.50 p 0.05 1.65 p 0.05 2.15 p 0.05 (2 SIDES) PACKAGE OUTLINE 0.25 p 0.05 0.50 BSC 2.38 p 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 3.00 p 0.10 (4 SIDES) R = 0.115 TYP 6 0.38 p 0.10 10 1.65 p 0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6) (DD) DFN 1103 5 0.200 REF 1 0.25 p 0.05 0.50 BSC 0.75 p 0.05 0.00 – 0.05 2.38 p 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 60878fb 13 LTC6087/LTC6088 PACKAGE DESCRIPTION GN Package 16-Lead Plastic SSOP (Narrow .150 Inch) (Reference LTC DWG # 05-08-1641) .189 – .196* (4.801 – 4.978) .045 p .005 16 15 14 13 12 11 10 9 .254 MIN .009 (0.229) REF .150 – .165 .229 – .244 (5.817 – 6.198) .0165 p .0015 .150 – .157** (3.810 – 3.988) .0250 BSC RECOMMENDED SOLDER PAD LAYOUT 1 .015 p .004 s 45o (0.38 p 0.10) .007 – .0098 (0.178 – 0.249) .0532 – .0688 (1.35 – 1.75) 2 3 4 5 6 7 8 .004 – .0098 (0.102 – 0.249) 0o – 8o 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 60878fb 14 LTC6087/LTC6088 PACKAGE DESCRIPTION DHC Package 16-Lead Plastic DFN (5mm × 3mm) (Reference LTC DWG # 05-08-1706) 0.65 p 0.05 3.50 p 0.05 1.65 p 0.05 2.20 p 0.05 (2 SIDES) PACKAGE OUTLINE 0.25 p 0.05 0.50 BSC 4.40 p 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS R = 0.115 TYP 5.00 p 0.10 (2 SIDES) R = 0.20 TYP 3.00 p 0.10 (2 SIDES) 9 0.40 p 0.10 16 1.65 p 0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6) PIN 1 NOTCH (DHC16) DFN 1103 8 0.200 REF 1 0.25 p 0.05 0.50 BSC 0.75 p 0.05 4.40 p 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 60878fb 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 5V 1.5k 5V 1N4148 5V IPD + PHOTODIODE ~3pF VOUT 0V – IPD • RF 1/2 LTC6087 – IPD – PHOTODIODE ~3pF VOUT 0V + IPD • RF 1/2 LTC6087 + 1N4148 –5V RF –5V 100k 1.5k NOTE: DIFFERENT DEVICES. NOT THE SAME LTC6087 CF 2pF 60878 TA02 –5V Almost Rail-to-Rail (0.3V to VCC) Gain-of-30 Current Sense Amplifier LOAD – VSENSE ISENSE + RSENSE VS 1007 1% GAIN OF 2 STAGE VCC + RCOMP 10k GAIN OF 15 STAGE 1/2 LTC6087 – CCOMP 1nF 2N7002 + 2007 1% 1/2 LTC6087 – 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. OUT 140k 1% 10k 1% 60878 TA03 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC2051/LTC2052 Dual/Quad Zero-Drift Op Amps 3μV VOS(MAX), 30nV/°C VOS Drift (MAX) LTC6078/LTC6079 Dual/Quad Micropower Precision Rail-to-Rail Op Amps 25μV VOS(MAX), 0.7μV/°C VOS Drift (MAX), 1pA IBIAS(MAX) LTC6240 Single Low Noise Rail-to-Rail Output Op Amp 7nV/√Hz Noise, 1pA IBIAS(MAX), 10V/μs Slew Rate LTC6241/LTC6242 Dual/Quad Low Noise Rail-to-Rail Output Op Amps 7nV/√Hz Noise, 0.2pA IBIAS, 18MHz Gain Bandwidth LTC6244 Dual 50MHz Rail-to-Rail Op Amps 100μV VOS(MAX), 1pA IBIAS, 40V/μs Slew Rate 60878fb 16 Linear Technology Corporation LT 0608 REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2007