LT6010 135µA, 14nV/√Hz, Rail-to-Rail Output Precision Op Amp with Shutdown U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO 35µV Maximum Offset Voltage 110pA Maximum Input Bias Current 135µA Supply Current Rail-to-Rail Output Swing 12µA Supply Current in Shutdown 120dB Minimum Voltage Gain (VS = ±15V) 0.8µV/°C Maximum VOS Drift 14nV/√Hz Input Noise Voltage 2.7V to ±18V Supply Voltage Operation Operating Temperature Range: – 40°C to 85°C Space Saving 3mm × 3mm DFN Package U APPLICATIO S ■ ■ ■ ■ Thermocouple Amplifiers Precision Photo Diode Amplifiers Instrumentation Amplifiers Battery-Powered Precision Systems The LT®6010 op amp combines low noise and high precision input performance with low power consumption and rail-to-rail output swing. Input offset voltage is trimmed to less than 35µV. The low drift and excellent long-term stability guarantee a high accuracy over temperature and over time. The 110pA maximum input bias current and 120dB minimum voltage gain further maintain this precision over operating conditions. The LT6010 works on any power supply voltage from 2.7V to 36V, and draws only 135µA of supply current on a 5V supply. A power saving shutdown feature reduces supply current to 12µA. The output voltage swings to within 40mV of either supply rail, making the amplifier a good choice for low voltage single supply operation. The LT6010 is fully specified at 5V and ±15V supplies and from –40°C to 85°C. The device is available in SO-8 and space-saving 3mm × 3mm DFN packages. This op amp is also available in dual (LT6011) and quad (LT6012) packages. , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO Single Supply Current Source for Platinum RTD Distribution of Offset Voltage Drift R5 1k, 5% 20 VS = ±2.5V SO-8 PACKAGES + VOUT = 100mV AT 0°C + 385µV/°C – –50°C TO 600°C 1k AT 0°C RTD* R4 1k, 5% R1 12.4k 0.1% C1 0.1µF 2 3 VS – + 7 6 LT6010 R2 100Ω 1% VS = 2.7V TO 20V ICC ≈ 320µA 4 PERCENTAGE OF UNITS (%) 18 16 14 12 10 8 6 4 2 6 1µF LT1790-1.25 1 2 4 VS 0 –0.8 –0.6 –0.4 –0.2 0 0.2 0.4 0.6 DISTRIBUTION (µV/°C) 0.8 6010 TA01b *OMEGA F3141 1kΩ, 0.1% PLATINUM RTD (800) 826-6342 6010 TA01a 6010f 1 LT6010 W W W AXI U U ABSOLUTE RATI GS (Note 1) Total Supply Voltage (V+ to V–) .............................. 40V Differential Input Voltage (Note 2) .......................... 10V Input Voltage, Shutdown Voltage ..................... V+ to V– Input Current (Note 2) ....................................... ±10mA Output Short-Circuit Duration (Note 3) ........... Indefinite Operating Temperature Range (Note 4) .. – 40°C to 85°C Specified Temperature Range (Note 5) ... – 40°C to 85°C Maximum Junction Temperature DD Package ..................................................... 125°C SO-8 Package .................................................. 150°C Storage Temperature Range DD Package ..................................... – 65°C to 125°C SO-8 Package .................................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U U W PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER TOP VIEW NULL 1 –IN 2 +IN 3 V – 4 – + 8 NULL 7 V+ 6 OUT 5 SHDN DD PACKAGE 8-LEAD (3mm × 3mm) PLASTIC DFN LT6010CDD LT6010IDD LT6010ACDD LT6010AIDD DD PART MARKING* TJMAX = 125°C, θJA = 160°C/W UNDERSIDE METAL INTERNALLY CONNECTED TO V– (PCB CONNECTION OPTIONAL) ORDER PART NUMBER TOP VIEW NULL 1 –IN 2 +IN 3 V– LADU 4 – + 8 NULL 7 V+ 6 OUT 5 SHDN S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 190°C/W LT6010CS8 LT6010IS8 LT6010ACS8 LT6010AIS8 S8 PART MARKING 6010 6010I 6010A 6010AI *Temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 5V, 0V; VCM = 2.5V; RL to 0V; SHDN = 0.2V, unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 7) LT6010AS8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010S8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010ADD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010DD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010AS8, LT6010S8 LT6010ADD,LT6010DD ● ● ∆VOS/∆T Input Offset Voltage Drift (Note 6) MIN TYP MAX UNITS 10 35 60 75 µV µV µV 20 55 85 110 µV µV µV 20 60 85 100 µV µV µV 30 80 110 135 µV µV µV 0.2 0.2 0.8 1.3 µV/°C µV/°C 6010f 2 LT6010 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 5V, 0V; VCM = 2.5V; RL to 0V; SHDN = 0.2V, unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS IOS Input Offset Current (Note 7) LT6010AS8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010S8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010ADD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010DD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010AS8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010S8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010ADD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010DD TA = 0°C to 70°C TA = –40°C to 85°C ● ● IB Input Bias Current (Note 7) Input Noise Voltage MIN 0.1Hz to 10Hz TYP MAX UNITS 20 110 150 200 pA pA pA 40 200 300 400 pA pA pA 20 200 300 400 pA pA pA 40 300 400 500 pA pA pA 20 ±110 ±150 ±200 pA pA pA 40 ±200 ±300 ±400 pA pA pA 20 ±200 ±300 ±400 pA pA pA 40 ±300 ±400 ±500 pA pA pA 400 nVP-P en Input Noise Voltage Density f = 1kHz 14 nV/√Hz in Input Noise Current Density f = 1kHz 0.1 pA/√Hz RIN Input Resistance Common Mode, VCM = 1V to 3.8V Differential 120 20 GΩ MΩ CIN Input Capacitance 4 pF V CM Input Voltage Range (Positive) Input Voltage Range (Negative) Guaranteed by CMRR Guaranteed by CMRR ● ● 3.8 Common Mode Rejection Ratio VCM = 1V to 3.8V ● 107 Minimum Supply Voltage Guaranteed by PSRR ● PSRR Power Supply Rejection Ratio VS = 2.7V to 36V, VCM = 1/2VS ● 112 135 dB A VOL Large-Signal Voltage Gain RL = 10k, VOUT = 1V to 4V RL = 2k, VOUT = 1V to 4V ● ● 300 250 2000 2000 V/mV V/mV VOUT Maximum Output Swing (Positive, Referred to V +) No Load, 50mV Overdrive CMRR 10 4 0.7 135 2.4 No Load, 50mV Overdrive ● V mV mV 120 170 220 mV mV 40 55 65 mV mV 150 225 275 mV mV ● ISINK = 1mA, 50mV Overdrive dB 2.7 55 65 ● Maximum Output Swing (Negative, Referred to 0V) V V 35 ● ISOURCE = 1mA, 50mV Overdrive 1 6010f 3 LT6010 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 5V, 0V; VCM = 2.5V; RL to 0V; SHDN = 0.2V, unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS ISC Output Short-Circuit Current (Note 3) VOUT = 0V, 1V Overdrive (Source) MIN TYP 14 ● 10 4 mA mA 10 4 21 ● mA mA 0.06 0.05 0.04 0.09 ● ● V/µs V/µs V/µs 250 225 330 ● kHz kHz VOUT = 5V, –1V Overdrive (Sink) SR GBW Slew Rate Gain Bandwidth Product AV = –10, RF = 50k, RG = 5k TA = 0°C to 70°C TA = –40°C to 85°C f = 10kHz MAX UNITS ts Settling Time AV = –1, 0.01%, VOUT = 1.5V to 3.5V 45 µs tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V Step 1 µs SHDN Pin Current SHDN ≤ V – ISHDN + 0.2V (On) ● SHDN = V – + 2.0V (Off) ● tSHDN SHDN Turn-On, Turn-Off Time SHDN = V – (On) to V – + 2.0V (Off) SHDN = V – + 2.0V (Off) to V – (On) IS Supply Current SHDN ≤ V – + 0.2V (On) TA = 0°C to 70°C TA = –40°C to 85°C 15 0.25 µA 25 µA µs µs 25 25 135 150 190 210 µA µA µA 12 25 50 µA µA ● ● SHDN = V– + 2.0V (Off) ● The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, RL to 0V; SHDN = –14.8V, unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS MIN VOS Input Offset Voltage (Note 7) LT6010AS8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010S8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010ADD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010DD TA = 0°C to 70°C TA = –40°C to 85°C ● ● ∆VOS/∆T Input Offset Voltage Drift (Note 6) LT6010AS8, LT6010S8 LT6010ADD,LT6010DD ● ● IOS Input Offset Current (Note 7) LT6010AS8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010S8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010ADD TA = 0°C to 70°C TA = –40°C to 85°C ● ● TYP MAX UNITS 10 60 80 110 µV µV µV 20 85 120 160 µV µV µV 20 85 105 135 µV µV µV 30 110 145 185 µV µV µV 0.2 0.2 0.8 1.3 µV/°C µV/°C 20 110 150 200 pA pA pA 40 200 300 400 pA pA pA 20 200 300 400 pA pA pA 6010f 4 LT6010 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, RL to 0V; SHDN = –14.8V, unless otherwise specified. (Note 5) SYMBOL PARAMETER IOS Input Offset Current (Note 7) IB Input Bias Current (Note 7) CONDITIONS MIN LT6010DD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010AS8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010S8 TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010ADD TA = 0°C to 70°C TA = –40°C to 85°C ● ● LT6010DD TA = 0°C to 70°C TA = –40°C to 85°C ● ● TYP MAX UNITS 40 300 400 500 pA pA pA 20 ±110 ±150 ±200 pA pA pA 40 ±200 ±300 ±400 pA pA pA 20 ±200 ±300 ±400 pA pA pA 40 ±300 ±400 ±500 pA pA pA Input Noise Voltage 0.1Hz to 10Hz 400 nVP-P en Input Noise Voltage Density f = 1kHz 13 nV/√Hz in Input Noise Current Density f = 1kHz RIN Input Resistance Common Mode, VCM = ±13.5V Differential CIN Input Capacitance VCM Input Voltage Range Guaranteed by CMRR CMRR Common Mode Rejection Ratio VCM = –13.5V to 13.5V 0.1 pA/√Hz 50 400 20 GΩ MΩ 4 pF ● ±13.5 ±14 V 115 112 135 ● dB dB ±1.2 ±1.35 Minimum Supply Voltage Guaranteed by PSRR ● PSRR Power Supply Rejection Ratio VS = ±1.35V to ±18V ● 112 135 dB AVOL Large-Signal Voltage Gain RL = 10k, VOUT = –13.5V to 13.5V 1000 600 2000 ● V/mV V/mV 500 300 1500 ● V/mV V/mV RL = 5k, VOUT = –13.5V to 13.5V VOUT Maximum Output Swing (Positive, Referred to V +) No Load, 50mV Overdrive 45 80 100 mV mV 140 195 240 mV mV 45 80 100 mV mV 150 250 300 mV mV ● ISOURCE = 1mA, 50mV Overdrive ● Maximum Output Swing (Negative, Referred to 0V) No Load, 50mV Overdrive ● ISINK = 1mA, 50mV Overdrive ● ISC Output Short-Circuit Current (Note 3) VOUT = 0V, 1V Overdrive (Source) V 10 5 15 ● mA mA 10 5 20 ● mA mA VOUT = 0V, –1V Overdrive (Sink) 6010f 5 LT6010 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, RL to 0V; SHDN = –14.8V, unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS SR Slew Rate AV = –10, RF = 50k, RG = 5k TA = 0°C to 70°C TA = –40°C to 85°C GBW Gain Bandwidth Product MIN TYP 0.08 0.07 0.05 0.11 ● ● V/µs V/µs V/µs 275 250 350 ● kHz kHz f = 10kHz MAX UNITS ts Settling Time AV = –1, 0.01%, VOUT = 0V to 10V 85 µs tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V Step 1 µs SHDN Pin Current SHDN ≤ V– + 0.2V (On) ● SHDN = V– + 2.0V (Off) ● ISHDN tSHDN SHDN Turn-On, Turn-Off Time SHDN = V – (On) to V – + 2.0V (Off) SHDN = V – + 2.0V (Off) to V – (On) IS Supply Current SHDN ≤ V– + 0.2V (On) TA = 0°C to 70°C TA = –40°C to 85°C µA 25 µA µs µs 25 25 260 330 380 400 µA µA µA 18 50 µA ● ● SHDN = V– + 2.0V (Off) Note 1: Absolute Maximum Ratings are those beyond which the life of the device may be impaired. Note 2: The inputs are protected by back–to–back diodes and internal series resistors. If the differential input voltage exceeds 10V, the input current must be limited to less than 10mA. Note 3: A heat sink may be required to keep the junction temperature below absolute maximum ratings. Note 4: Both the LT6010C and LT6010I are guaranteed functional over the operating temperature range of –40°C to 85°C. Note 5: The LT6010C is guaranteed to meet the specified performance 0.25 15 from 0°C to 70°C and is designed, characterized and expected to meet specified performance from –40°C to 85°C but is not tested or QA sampled at these temperatures. The LT6010I is guaranteed to meet specified performance from –40°C to 85°C. Note 6: This parameter is not 100% tested. Note 7: The specifications for VOS, IB and IOS depend on the grade and on the package. The following table clarifies the notations used in the specification table: Standard Grade A Grade S8 Package LT6010S8 LT6010AS8 DFN Package LT6010DD LT6010ADD U W TYPICAL PERFOR A CE CHARACTERISTICS Input Offset Voltage vs Temperature Distribution of Input Offset Voltage 100 120 VS = 5V, 0V REPRESENTATIVE UNITS 100 75 20 15 10 OFFSET VOLTAGE (µV) PERCENT OF UNITS (%) 25 125 LT6010AS8 VS = 5V, 0V TA = 25°C OFFSET VOLTAGE (µV) 30 Offset Voltage vs Input Common Mode Voltage 50 25 0 –25 –50 VS = ±15V TYPICAL PART 80 TA = 85°C 60 TA = –40°C 40 20 TA = 25°C –75 5 0 –100 0 –45 –35 –25 –15 –5 5 15 25 35 45 INPUT OFFSET VOLTAGE (µV) 6010 G01 –125 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 6010 G02 –20 –15 5 0 10 –10 –5 INPUT COMMON MODE VOLTAGE (V) 15 6010 G03 6010f 6 LT6010 U W TYPICAL PERFOR A CE CHARACTERISTICS Input Bias Current vs Input Common Mode Voltage Input Bias Current vs Temperature VS = 5V, 0V TYPICAL PART INPUT BIAS CURRENT (pA) 800 TA = –40°C 700 20pA/DIV 600 500 400 TA = 25°C TA = 85°C 300 200 100 IB + –100 –50 IB– 25 0 75 50 TEMPERATURE (°C) –25 100 125 2V/DIV 0.01Hz to 1Hz Noise VS = ±15V TA = 25°C VS = ±15V TA = 25°C 0.01 RESISTOR NOISE ONLY 0.001 10k 100k 1M 10M SOURCE RESISTANCE (Ω) NOISE VOLTAGE (0.2µV/DIV) TOTAL NOISE 1k 100M 1 0 2 3 4 5 6 TIME (SEC) 7 8 6010 G07 1 VS = 5V, 0V NO LOAD –20 –40 OUTPUT HIGH –60 60 OUTPUT LOW 40 20 75 50 25 TEMPERATURE (°C) 0 10 0 100 125 6010 G10 10 20 30 40 50 60 70 80 90 100 TIME (SEC) 6010 G09 Output Saturation Voltage vs Load Current (Output High) OUTPUT HIGH SATURATION VOLTAGE (V) OUTPUT VOLTAGE SWING (mV) V+ 9 6010 G08 Output Voltage Swing vs Temperature V– – 50 – 25 6010 G06 0.1Hz to 10Hz Noise 0.1 1000 6010 G05 VS = 5V, 0V TA = 25°C f = 1kHz 0.0001 100 10 100 FREQUENCY (Hz) 1 NOISE VOLTAGE (0.2µV/DIV) TOTAL INPUT NOISE (µV/√Hz) 1 VOLTAGE NOISE 15 6010 G04 10 100 10 –100 –15 Total Input Noise vs Source Resistance 1000 CURRENT NOISE 100 Output Saturation Voltage vs Load Current (Output Low) 1 VS = 5V, 0V OUTPUT LOW SATURATION VOLTAGE (V) 0 VS = ±15V TA = 25°C INPUT CURRENT NOISE DENSITY (fA/√Hz) 900 en, in vs Frequency 100 INPUT VOLTAGE NOISE DENSITY (nV/√Hz) 1000 TA = 85°C TA = 25°C 0.1 TA = –40°C 0.01 0.01 0.1 1 LOAD CURRENT (mA) 10 6010 G11 VS = 5V, 0V TA = 85°C TA = 25°C 0.1 TA = –40°C 0.01 0.01 0.1 1 LOAD CURRENT (mA) 10 6010 G12 6010f 7 LT6010 U W TYPICAL PERFOR A CE CHARACTERISTICS Warm-Up Drift Supply Current vs Supply Voltage 400 350 TA = 85°C 300 TA = 25°C 250 200 TA = –40°C 150 100 10 VS = 5V, 0V VOUT = 2VP-P TA = 25°C AV = 1: RL = 10k AV = –1: RF = RG = 10k 1 ±15V 2 THD + NOISE (%) CHANGE IN OFFSET VOLTAGE (µV) 450 SUPPLY CURRENT (µA) THD + Noise vs Frequency 3 500 ±2.5V 1 0.1 0.01 AV = –1 AV = 1 0.001 50 0 0 0 2 4 30 60 90 120 TIME AFTER POWER-ON (SECONDS) 6 8 10 12 14 16 18 20 SUPPLY VOLTAGE (±V) THD + Noise vs Frequency VS = ±15V VIN = 20VP-P TA = 25°C 0.01 AV = 1 6 0.1% 0.01% 4 10k 20 30 40 50 60 70 SETTLING TIME (µs) 0.01% 4 80 90 0 20 30 40 50 60 70 SETTLING TIME (µs) 80 90 PSRR vs Frequency TA = 25°C 140 120 100 VS = ±15V 80 10 6010 G18 140 POWER SUPPLY REJECTION RATIO (dB) COMMON MODE REJECTION RATIO (dB) 0.1% 6010 G17 CMRR vs Frequency VS = 5V, 0V 60 6 0 10 0 6010 G16 160 VS = ±15V AV = –1 2 0 100 1k FREQUENCY (Hz) 100k 8 2 0.001 0.0001 10 VS = ±15V AV = 1 OUTPUT STEP (V) AV = –1 1k 10k FREQUENCY (Hz) Settling Time vs Output Step 10 8 0.1 100 6010 G15 Settling Time vs Output Step 10 OUTPUT STEP (V) THD + NOISE (%) 1 0.0001 10 6010 G14 6010 G13 10 150 40 20 VS = 5V, 0V TA = 25°C 120 100 80 +PSRR 60 –PSRR 40 20 0 0 1 10 100 1k 10k FREQUENCY (Hz) 100k 1M 6010 G20 0.1 1 10 100 1k 10k 100k FREQUENCY (Hz) 1M 6010 G21 6010f 8 LT6010 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Impedance vs Frequency 1000 Open-Loop Gain vs Frequency 140 VS = 5V, 0V TA = 25°C 10 AV = 100 1 AV = 10 80 60 40 20 0.01 10 100 1k 10k FREQUENCY (Hz) 100k 1M –40 0.01 0.1 10 1 1k 10k GAIN (dB) –10 40 VS = 5V, 0V TA = 25°C CL = 50pF –5 –10 –15 –15 –20 –20 1k 1M 10k 100k FREQUENCY (Hz) 6010 G25 35 30 25 VS = ±15V 20 15 10 VS = 5V, 0V 5 0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (°C) 1M 6010 G26 Small-Signal Transient Response –280 10M Supply Current in Shutdown Mode vs Temperature 0 –5 100k 1M FREQUENCY (Hz) 6010 G24 CL = 500pF 0 GAIN (dB) – 240 – 40 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 5 CL = 500pF 10k 100k FREQUENCY (Hz) –200 Gain vs Frequency, AV = –1 VS = 5V, 0V TA = 25°C 1k 0 6010 G23 Gain vs Frequency, AV = 1 CL = 50pF –160 PHASE 10 –30 6010 G22 5 GAIN 20 SUPPLY CURRENT IN SHUTDOWN (µA) 1 –120 30 – 20 –20 AV = 1 –80 –10 0 0.1 10 40 OPEN-LOOP GAIN (dB) OPEN-LOOP GAIN (dB) 100 VS = 5V, 0V TA = 25°C RL = 10k 50 PHASE SHIFT (DEG) OUTPUT IMPEDANCE (Ω) VS = 5V, 0V TA = 25°C RL = 10k 120 100 Gain and Phase vs Frequency 60 6010 G30 Large-Signal Transient Response Rail-to-Rail Output Swing 5V 20mV/DIV 0V 2V/DIV 1V/DIV 0V AV = 1 2µs/DIV 6011 G27 AV = –1 VS = ±15V 50µs/DIV 6011 G28 AV = –1 VS = 5V, 0V 100µs/DIV 6011 G29 6010f 9 LT6010 U W U U APPLICATIO S I FOR ATIO Preserving Input Precision Preserving the input accuracy of the LT6010 requires that the applications circuit and PC board layout do not introduce errors comparable to or greater than the 20µV typical offset of the amplifier. 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 currents across the board can also generate temperature differentials. The extremely low input bias currents (20pA typical) allow high accuracy to be maintained with high impedance sources and feedback resistors. The LT6010 low input bias currents are obtained by a cancellation circuit onchip. The input bias currents are permanently trimmed at wafer testing to a low level. Do not try to balance the input resistances in each input lead; instead, keep the resistance at either input as low as possible for maximum accuracy. Leakage currents on the PC board can be higher than the LT6010’s input bias current. For example, 10GΩ of leakage between a 15V supply lead and an input lead will generate 1.5nA! Surround the input leads by a guard ring, driven to the same potential as the input common mode, to avoid excessive leakage in high impedance applications. Input Protection The LT6010 features on-chip back-to-back diodes between the input devices, along with 500Ω resistors in series with either input. This internal protection limits the input current to approximately 10mA (the maximum allowed) for a 10V differential input voltage. Use additional external series resistors to limit the input current to 10mA in applications where differential inputs of more than 10V are expected. For example, a 1k resistor in series with each input provides protection against 30V differential voltage. Input Common Mode Range The LT6010 output is able to swing nearly to each power supply rail (rail-to-rail out), but the input stage is limited to operating between V– + 1V and V+ – 1.2V. Exceeding this common mode range will cause the gain to drop to zero, however no phase reversal will occur. Total Input Noise The LT6010 amplifier contributes negligible noise to the system when driven by sensors (sources) with impedance between 20kΩ and 1MΩ. Throughout this range, total input noise is dominated by the 4kTRS noise of the source. If the source impedance is less than 20kΩ, the input voltage noise of the amplifier starts to contribute with a minimum noise of 14nV/√Hz for very low source impedance. If the source impedance is more than 1MΩ, the input current noise of the amplifier, multiplied by this high impedance, starts to contribute and eventually dominate. Total input noise spectral density can be calculated as: vn(TOTAL) = en2 + 4kTRS + (in RS )2 where en = 14nV/√Hz, in = 0.1pA/√Hz and RS the total impedance at the input, including the source impedance. 6010f 10 LT6010 U W U U APPLICATIO S I FOR ATIO Offset Voltage Adjustment The input offset voltage of the LT6010 and its drift with temperature are permanently trimmed at wafer testing to the low level as specified in the electrical characteristic. However, if further adjustment of VOS is desired, nulling with a 50k potentiometer is possible and will not degrade drift with temperature. Trimming to a value other than zero creates a drift of (VOS/300µV) µV/°C, e.g., if VOS is adjusted to 300µV, the change in drift will be 1µV/°C. The adjustment range with a 50k pot is approximately ±0.9mV (see Figures 1A and 1B). The sensitivity and resolution of the nulling can be improved by using a smaller pot in conjunction with fixed resistors. The configuration shown has an approximate nulling range of ±150µV (see Figures 2A and 2B). Standard Adjustment VCC 50k 1 2 – INPUT 8 7 LT6010 3 + 6 OUTPUT CHANGE IN OFFSET VOLTAGE (mV) 1.0 4 6010 F01a 0.8 0.6 0.4 0.2 0 –0.2 –0.4 –0.6 –0.8 –1.0 Vee 0 0.2 0.4 0.6 0.8 POTENTIOMETER POSITION 1.0 6010 F01b Figure 1A Figure 1B Improved Sensitivity Adjustment 10k VCC 50k 1 2 – 10k 8 7 LT6010 INPUT 3 + 6 OUTPUT CHANGE IN OFFSET VOLTAGE (µV) 200 150 100 50 0 –50 –100 –150 4 6010 F02a Vee –200 0 0.2 0.4 0.6 0.8 POTENTIOMETER POSITION 1.0 6010 F02b Figure 2A Figure 2B 6010f 11 LT6010 U W U U APPLICATIO S I FOR ATIO Shutdown Rail-to-Rail Operation The LT6010 can be put into shutdown mode to conserve power. When the SHDN pin is biased at less than 0.2V above the negative supply, the part operates normally. When pulled 2V or more above V–, the supply current drops to about 12µA, shutting down the op amp. The LT6010 outputs can swing to within millivolts of either supply rail, but the inputs cannot. However, for most op amp configurations, the inputs need to swing less than the outputs. Figure 4 shows the basic op amp configurations, lists what happens to the op amp inputs and specifies whether or not the op amp must have rail-to-rail inputs. Select a rail-to-rail input op amp only when really necessary, because the input precision specifications are usually inferior. The output of the LT6010 op amp is not isolated from the inputs while in shutdown mode. Therefore, this shutdown feature cannot be used for multiplexing applications. There is an internal 85k resistor at the SHDN pin. If the SHDN voltage source is more than 2V above the negative supply, an external series resistor can be placed between the source and SHDN pin to reduce SHDN pin current (see Figure 3). For an example of suggested values see Table 1. The resistors listed ensure that the voltage at the SHDN pin is 2V above the negative supply. VIN RSHDN (kΩ) 2 NONE 3 77k 4 153k 5 230k RG – RF INVERTING: AV = –RF/RG OP AMP INPUTS DO NOT MOVE, BUT ARE FIXED AT DC BIAS POINT VREF Table 1 VSHDN (V) + VREF INPUT DOES NOT HAVE TO BE RAIL-TO-RAIL + VIN VIN – + – RF RSHDN + – SHDN 5 85k RG VREF VSHDN VEE VEE 6010 F03 Figure 3 Capacitive Loads The LT6010 can drive capacitive loads up to 500pF 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 that the amplifier can drive. NONINVERTING: AV = 1 + RF/RG INPUTS MOVE AS MUCH AS VIN, BUT THE OUTPUT MOVES MORE INPUT MAY NOT HAVE TO BE RAIL-TO-RAIL 6010 F04 NONINVERTING: AV = 1 INPUTS MOVE AS MUCH AS THE OUTPUT INPUT MUST BE RAIL-TO-RAIL FOR OVERALL CIRCUIT RAIL-TO-RAIL PERFORMANCE Figure 4. Some Op Amp Configurations Do Not Require Rail-to-Rail Inputs to Achieve Rail-to-Rail Outputs 6010f 12 LT6010 W W SI PLIFIED SCHE ATIC V+ 7 NULL 1 R3 8 R4 NULL R6 R5 Q7 Q18 Q6 Q8 RC1 Q5 Q4 Q3 BIAS CURRENT GENERATOR 2 +IN 3 D1 R2 500Ω SHDN 5 V– 4 D3 Q17 Q12 Q1 Q2 D5 Q14 Q10 C B A D2 6 OUT D4 Q16 R1 500Ω –IN Q13 C2 Q21 B A Q19 C1 C3 Q20 Q11 Q15 Q9 Q10 6010 SS 6010f 13 LT6010 U PACKAGE DESCRIPTIO DD Package 8-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1698) 0.675 ±0.05 3.5 ±0.05 1.65 ±0.05 2.15 ±0.05 (2 SIDES) PACKAGE OUTLINE 0.28 ± 0.05 0.50 BSC 2.38 ±0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS R = 0.115 TYP 5 3.00 ±0.10 (4 SIDES) 0.38 ± 0.10 8 1.65 ± 0.10 (2 SIDES) PIN 1 TOP MARK (DD8) DFN 0203 0.200 REF 0.75 ±0.05 0.00 – 0.05 4 0.28 ± 0.05 1 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-1) 2. ALL DIMENSIONS ARE IN MILLIMETERS 3. 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 4. EXPOSED PAD SHALL BE SOLDER PLATED 6010f 14 LT6010 U PACKAGE DESCRIPTIO S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 .050 BSC 8 .245 MIN 7 6 5 .160 ±.005 .150 – .157 (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) .030 ±.005 TYP 1 RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) 3 4 .053 – .069 (1.346 – 1.752) .004 – .010 (0.101 – 0.254) 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 2 .014 – .019 (0.355 – 0.483) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) .050 (1.270) BSC SO8 0303 6010f 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 LT6010 U TYPICAL APPLICATIO Precision JFET Input Transimpedance Photodiode Amplifier C4 0.5pF C3 1pF V+ R3 100k, 1% J1 + – U1 LT6010 R1 330k, 5% R4 2.55k – R2 1k 5% C2 0.1µF S1 C1 0.01µF V– V– U2 LT6230 VOUT + J1: PHILIPS BF862 S1: SIEMENS/INFINEON SFH203 PHOTODIODE (~3pF) VSUPPLY = ±5V ISUPPLY = 5.6mA BANDWIDTH = 6MHz AZ = 100kΩ OUTPUT OFFSET ≈ 50µV TYPICALLY 6010 TA02 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT6011/6012 Dual/Quad Precision Op Amps 135µA, Rail-to-Rail Output LT1001 Low Power, Picoamp Input Precision Op Amp 250pA Input Bias Current LT1880 Rail-to-Rail Output, Picoamp Input Precision Op Amp CLOAD up to 1000pF 6010f 16 Linear Technology Corporation LT/TP 1103 1K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2003