LTC6078/LTC6079 Micropower Precision, Dual/Quad CMOS Rail-to-Rail Input/Output Amplifiers U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 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 U APPLICATIO S ■ ■ ■ ■ 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. U ■ 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 U 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 U 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