LTC1049CS8

LTC1049 Low Power Zero-Drift Operational Amplifier with Internal Capacitors FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Low Supply Current: 200µA No External Components Required Maximum Offset Voltage: 10µV Maximum Offset Voltage Drift: 0.1µV/°C Single Supply Operation: 4.75V to 16V Input Common Mode Range Includes Ground Output Swings to Ground Typical Overload Recovery Time: 6ms Available in 8-Pin SO and PDIP Packages The LTC®1049 is a high performance, low power zero-drift operational amplifier. The two sample-and-hold capacitors usually required externally by other chopper stabilized amplifiers are integrated on the chip. Further, the LTC1049 offers superior DC and AC performance with a nominal supply current of only 200µA. The LTC1049 has a typical offset voltage of 2µV, drift of 0.02µV/°C, 0.1Hz to 10Hz input noise voltage of 3µVP-P and typical voltage gain of 160dB. The slew rate is 0.8V/µs with a gain bandwidth product of 0.8MHz. Overload recovery time from a saturation condition is 6ms, a significant improvement over chopper amplifiers using external capacitors. The LTC1049 is available in a standard 8-pin plastic dual in line, as well as an 8-pin SO package. The LTC1049 can be a plug-in replacement for most standard op amps with improved DC performance and substantial power savings. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. APPLICATIO S ■ ■ ■ ■ ■ ■ 4mA to 20mA Current Loops Thermocouple Amplifiers Electronic Scales Medical Instrumentation Strain Gauge Amplifiers High Resolution Data Acquisition TYPICAL APPLICATIO Single Supply Thermocouple Amplifier 0.068µF VIN = 5V 246k 1k 2 K LT 1025A GND 4 R– 5 ® 2 3 – + 7 6 VOUT = 0V TO 4V FOR 0°C TO 400°C LTC1049 7 – + 4 TYPE K 0.1µF SUPPLY CURRENT = 280µA U LTC1049 • TA01 U U 1049fb 1 LTC1049 ABSOLUTE AXI U RATI GS Total Supply Voltage (V + to V –) ............................... 18V Input Voltage (Note 2) .......... (V + + 0.3V) to (V – – 0.3V) Output Short-Circuit Duration .......................... Indefinite PACKAGE/ORDER I FOR ATIO TOP VIEW NC 1 –IN 2 +IN 3 V– 4 8 7 6 5 NC V+ OUT NC ORDER PART NUMBER LTC1049CN8 +IN 2 V– 3 4 N8 PACKAGE 8-LEAD PDIP TJMAX = 110°C, θJA = 130°C/W J8 PACKAGE 8-LEAD CERDIP TJMAX = 150°C, θJA = 100°C/W LTC1049CJ8 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 110°C, θJA = 200°C/W OBSOLETE PACKAGE Consider the N8 Package as an Alternate Source 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. ELECTRICAL CHARACTERISTICS PARAMETER Input Offset Voltage Average Input Offset Drift Long Term Offset Voltage Drift Input Offset Current Input Bias Current CONDITIONS (Note 3) (Note 3) The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ± 5V, unless noted. MIN ● ● ● Input Noise Voltage Input Noise Current Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Maximum Output Voltage Swing 0.1Hz to 10Hz 0.1Hz to 1Hz f = 10Hz (Note 4) VCM = V – to 2.7V VS = ±2.375V to ± 8V RL = 100kΩ, VOUT = ± 4.75V RL = 10kΩ RL = 100kΩ RL = 10kΩ, CL = 50pF No Load ● ● ● ● ● Slew Rate Gain Bandwidth Product Supply Current Internal Sampling Frequency ● 2 + – U U W WW U W (Note 1) Operating Temperature Range .................–40°C to 85°C Storage Temperature Range ................. –65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C NC –IN 1 TOP VIEW 8 7 6 5 NC V+ OUT NC ORDER PART NUMBER LTC1049CS8 S8 PART MARKING 1049 TYP ±2 ±0.02 50 ±30 ±15 3 1 2 130 130 160 –4.9/4.2 ±4.97 0.8 0.8 200 700 MAX ±10 ±0.1 ±100 ±150 ±50 ±150 110 110 130 –4.6/3.2 ±4.9 330 495 UNITS µV µV/°C nV √mo pA pA pA pA µV P-P µV P-P fA √Hz dB dB dB V V V V/ µs MHz µA µA Hz 1049fb LTC1049 ELECTRICAL CHARACTERISTICS 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: Connecting any terminal to voltages greater than V + or less than V – may cause destructive latch-up. It is recommended that no sources operating from external supplies be applied prior to power-up of the LTC1049. Note 3: These parameters are guaranteed by design. Thermocouple effects preclude measurement of these voltage levels in high speed automatic test systems. VOS is measured to a limit determined by test equipment capability. Note 4: Current Noise is calculated from the formula: IN = √(2q • Ib) where q = 1.6 • 10–19 Coulomb. TYPICAL PERFOR A CE CHARACTERISTICS Voltage Noise vs Frequency 140 120 COMMON MODE VOLTAGE (V) VOLTAGE NOISE (nV/√Hz) VOLTAGE GAIN (dB) 100 80 60 40 20 10 100 1k FREQUENCY (Hz) LTC1049 • TP01 10k Supply Current vs Supply Voltage 500 400 SHORT-CIRCUIT OUTPUT CURRENT (mA) SUPPLY CURRENT (µA) 340 280 220 160 100 5 6 7 8 9 10 11 12 13 14 15 TOTAL SUPPLY VOLTAGE (V) LTC1049 • TPC04 SUPPLY CURRENT (µA) UW Common Mode Input Range vs Supply Voltage 8 6 4 2 0 –2 –4 –6 –8 100k Gain/Phase vs Frequency 120 VS = ± 5V 100 NO LOAD 80 PHASE 60 40 GAIN 20 0 –20 160 180 200 1k 10k 100k FREQUENCY (Hz) 1M 220 10M LTC1049 • TPC03 VCM = V – 60 80 PHASE SHIFT (DEGREES) 100 120 140 0 1 4 5 2 3 6 SUPPLY VOLTAGE (±V) 7 8 –40 100 LTC1049 • TPC02 Supply Current vs Temperature 1.2 0.8 0.4 0 –3 –6 –9 Output Short-Circuit Current vs Supply Voltage 400 300 ≈ ≈ 200 100 0 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 4 14 8 10 12 6 TOTAL SUPPLY VOLTAGE, V+ TO V–(V) 16 LTC1049 • TPC05 LTC1049 • TPC06 1049fb 3 LTC1049 TYPICAL PERFOR A CE CHARACTERISTICS Sampling Frequency vs Supply Voltage 3000 5 2500 SAMPLING FREQUENCY (kHz) SAMPLING FREQUENCY (Hz) 2000 CMRR (dB) 1500 1000 4 14 16 6 8 10 12 TOTAL SUPPLY VOLTAGE, V + TO V – (V) LTC1049 • TPC07 Overload Recovery 400mV 0.2V/DIV 0V 0V 2V/DIV –5V AV = – 100 VS = ± 5V 0.5ms/DIV LTC1049 • TPC10 VS = ± 5V NOISE VOLTAGE 1µV/DIV 4 UW Sampling Frequency vs Temperature VS = ± 5V CMRR vs Frequency 160 140 VS = ± 5V 4 120 3 100 80 60 40 20 2 1 0 50 25 0 75 100 –50 –25 AMBIENT TEMPERATURE (°C) 125 0 1 10 100 1k FREQUENCY (Hz) 10k 100k LTC1049 • TPC08 LTC1049 • TPC09 Small-Signal Transient Response Large-Signal Transient Response INPUT OUTPUT 100mV STEP 6V STEP 1µs/DIV 5µs/DIV AV = 1 RL = 10k CL = 50pF VS = ±5V LTC1049 • TPC11 AV = 1 RL = 10k CL = 50pF VS = ±5V LTC1049 • TPC12 LTC1049 DC to 1Hz Noise 1Hz NOISE 1µV/DIV 10s/DIV LTC1049 • TPC13 1049fb LTC1049 TYPICAL PERFOR A CE CHARACTERISTICS LTC1049 DC to 10Hz Noise VS = ± 5V NOISE VOLTAGE 1µV/DIV TEST CIRCUITS Electrical Characteristics Test Circuit 140 120 COMMON MODE VOLTAGE (V) VOLTAGE NOISE (nV/√Hz) 100 80 60 40 20 10 100 1k FREQUENCY (Hz) LTC1049 • TP01 UW 10Hz NOISE 1µV/DIV 1s/DIV LTC1049•TPC14 DC to 10Hz and DC to 1Hz Noise Test Circuit 8 6 4 2 0 –2 –4 –6 –8 VCM = V – 10k 100k 0 1 4 5 2 3 6 SUPPLY VOLTAGE (±V) 7 8 LTC1049 • TPC02 1049fb 5 LTC1049 APPLICATIO S I FOR ATIO ACHIEVING PICOAMPERE/MICROVOLT PERFORMANCE Picoamperes In order to realize the picoampere level of accuracy of the LTC1049, proper care must be exercised. Leakage currents in circuitry external to the amplifier can significantly degrade performance. High quality insulation should be used (e.g., Teflon™, Kel-F); cleaning of all insulating surfaces to remove fluxes and other residues will probably be necessary—particularly for high temperature performance. Surface coating may be necessary to provide a moisture barrier in high humidity environments. Board leakage can be minimized by encircling the input connections with a guard ring operated at a potential close to that of the inputs: in inverting configurations, the guard ring should be tied to ground; in noninverting connections, to the inverting input. Guarding both sides of the printed circuit board is required. Bulk leakage reduction depends on the guard ring width. Microvolts Thermocouple effects must be considered if the LTC1049’s ultralow drift is to be fully utilized. Any connection of dissimilar metals forms a thermoelectric junction producing an electric potential which varies with temperature (Seebeck effect). As temperature sensors, thermocouples exploit this phenomenon to produce useful information. In low drift amplifier circuits the effect is a primary source of error. Connectors, switches, relay contacts, sockets, resistors, solder, and even copper wire are all candidates for thermal EMF generation. Junctions of copper wire from different manufacturers can generate thermal EMFs of 200nV/°C — twice the maximum drift specification of the LTC1049. The copper/kovar junction, formed when wire or printed circuit traces contact a package lead, has a thermal EMF of approximately 35µV/°C—300 times the maximum drift specification of the LTC1049. 6 U Minimizing thermal EMF-induced errors is possible if judicious attention is given to circuit board layout and component selection. It is good practice to minimize the number of junctions in the amplifier’s input signal path. Avoid connectors, sockets, switches, and relays where possible. In instances where this is not possible, attempt to balance the number and type of junctions so that differential cancellation occurs. Doing this may involve deliberately introducing junctions to offset unavoidable junctions. PACKAGE-INDUCED OFFSET VOLTAGE Package-induced thermal EMF effects are another important source of errors. It arises at the copper/kovar junctions formed when wire or printed circuit traces contact a package lead. Like all the previously mentioned thermal EMF effects, it is outside the LTC1049’s offset nulling loop and cannot be cancelled. The input offset voltage specification of the LTC1049 is actually set by the package-induced warm-up drift rather than by the circuit itself. The thermal time constant ranges from 0.5 to 3 minutes, depending on package type. LOW SUPPLY OPERATION The minimum supply for proper operation of the LTC1049 is typically below 4.0V (± 2.0V). In single supply applications, PSRR is guaranteed down to 4.7V (± 2.35V) to ensure proper operation down to the minimum TTL specified voltage of 4.75V. PIN COMPATIBILITY The LTC1049 is pin compatible with the 8-pin versions of 7650, 7652 and other chopper-stabilized amplifiers. The 7650 and 7652 require the use of two external capacitors connected to Pins 1 and 8 which are not needed for the LTC1049. Pins 1, 5, and 8 of the LTC1049 are not connected internally; thus, the LTC1049 can be a direct plugin for the 7650 and 7652, even if the two capacitors are left on the circuit board. 1049fb W UU LTC1049 TYPICAL APPLICATIO S Low Power, Low Hold Step Sample-and-Hold 5V 13 LTC201 VIN 3 2 3 4.5 2 5V 7 6 LTC1049 VOUT U – + 4 S/H 1 0.47µF MYLAR DROOP ≤ 1mV/s HOLD STEP ≤ 20µV IS = 250µA TYP LTC1049 • TA02 1049fb 7 LTC1049 TYPICAL APPLICATIO S Low Power, Single Supply, Low Offset Instrumentation Amp 5V 8 U 198k 2k 2k 198k 2 – + 7 6 2 – + 7 6 VOUT LTC1049 3 4 LTC1049 3 4 – VIN + VIN GAIN = 100 IS = 400µA CMRR ≥ 60dB, WITH 0.1% RESISTORS (RESISTORS LIMITED) LTC1049 • TA03 1049fb LTC1049 PACKAGE DESCRIPTIO CORNER LEADS OPTION (4 PLCS) .045 – .068 (1.143 – 1.650) FULL LEAD OPTION .300 BSC (7.62 BSC) .008 – .018 (0.203 – 0.457) NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS U J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) .405 (10.287) MAX 8 7 6 5 .005 (0.127) MIN .023 – .045 (0.584 – 1.143) HALF LEAD OPTION .025 (0.635) RAD TYP 1 2 3 .220 – .310 (5.588 – 7.874) 4 .200 (5.080) MAX .015 – .060 (0.381 – 1.524) 0° – 15° .045 – .065 (1.143 – 1.651) .014 – .026 (0.360 – 0.660) .100 (2.54) BSC .125 3.175 MIN J8 0801 OBSOLETE PACKAGE 1049fb 9 LTC1049 PACKAGE DESCRIPTIO .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 8.255 +0.889 –0.381 ) INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) NOTE: 1. DIMENSIONS ARE 10 U N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 .255 ± .015* (6.477 ± 0.381) 1 2 3 4 .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 .100 (2.54) BSC 1049fb LTC1049 PACKAGE DESCRIPTIO .050 BSC 8 .245 MIN .030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 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) 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. U S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) NOTE 3 7 6 5 .045 ±.005 .160 ±.005 .228 – .244 (5.791 – 6.197) .150 – .157 (3.810 – 3.988) NOTE 3 1 2 3 4 .053 – .069 (1.346 – 1.752) .004 – .010 (0.101 – 0.254) .014 – .019 (0.355 – 0.483) TYP .050 (1.270) BSC SO8 0303 1049fb 11 LTC1049 TYPICAL APPLICATIO 6V V+ K – Thermocouple-Based Temperature to Frequency Converter 0.02µF 6V 10k 100k LT1025 R NC Q1 2N3904 TYPE K THERMOCOUPLE –+ GND 6.81k* C3 0.47µF 1.5k 100°C TRIM 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● U – LTC1049 1M Q2 2N3906 l1 C1 100pF l2 100k l3 OUTPUT 0 – 100°C = 0 – 1kHz + C4 300pF 6V 240k + 6.8µF LT1004 – 1.2 16 9 15 S1 14 C2 390pF † 11 S4 10 *IRC/TRW–MTR–5/+120ppm †POLYSTYRENE = 74C14 IS = 360µA SUPPLY RANGE = 4.5V to 10V S3 2 3 6 S2 7 LTC201 1 8 LTC1049 • TA04 1049fb LT 0406 REV B • PRINTED IN USA www.linear.com © LINEAR TECHNOLOGY CORPORATION 1991