LTC1047 Dual Micropower Zero-Drift Operational Amplifier with Internal Capacitors DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The LTC®1047 is a micropower, high performance dual zero-drift operational amplifier. The sample-and-hold capacitors usually required by other chopper amplifiers are integrated on-chip, minimizing the need for external components. No External Components Required Maximum Offset Voltage: 10µV Maximum Offset Voltage Drift: 50nV/°C Supply Current: 80µA Minimum CMRR: 110dB Minimum PSRR: 105dB Single Supply Operation: 4.75V to 16V Common Mode Range Includes GND Output Swings to GND Typical Overload Recovery Time: 70ms Pin Compatible with Industry Standard Dual Op Amps The LTC1047 has a typical offset voltage of 3µV, drift of 10nV/°C, input noise voltage typically 3.5µVP-P, and typical voltage gain of 150dB. The common mode rejection is 110dB minimum, with minimum power supply rejection of 105dB. The LTC1047 also offers a 0.2V/µs slew rate and a gain bandwidth product of 200kHz. Overload recovery time from saturation is 70ms, four times faster than chopper amplifiers with external capacitors. U APPLICATIO S ■ ■ ■ ■ ■ The LTC1047 is available in a standard plastic 8-pin PDIP as well as a 16-pin SW package. The LTC1047 is a plug-in replacement for most dual op amps with improved DC performance and substantial power savings. Thermocouple Amplifiers Electronic Scales Battery Powered Instrumentation Strain Gauge Amplifiers Remote Located Sensors , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO Micropower Single Supply Instrumentation Amplifier CMRR vs Frequency 140 5V 120 4 1/2 LTC1043 100Ω 18 100k 5V 3 CS 1µF CH 1µF 6 2 +IN 100 15 6 5 16 17 0.1µF CMRR (dB) –IN CS = CH = 1µF 5 – 60 1/2 LTC1047 + 80 7 VOUT 40 4 GAIN = 1000 CMRR > = 120dB AT 60Hz VOS = < 10µV IS = 62µA (INCLUDING THE LTC1043) 20 100 LTC1047 • TA01 1k 10k 100k FREQUENCY OF COMMON MODE SIGNAL LT1047 • TA02 1047fa 1 LTC1047 W W W AXI U U ABSOLUTE RATI GS (Note 1) Total Supply Voltage (V + to V –) ............................... 16V Input Voltage (Note 2) .......... (V + + 0.3V) to (V – – 0.3V) Output Short-Circuit Duration .......................... Indefinite Storage Temperature Range ................. – 65°C to 150°C Operating Temperature Range ..................... 0°C to 70°C Lead Temperature (Soldering, 10 sec).................. 300°C U U W PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER TOP VIEW NC 1 16 NC NC 2 15 NC OUT A 3 14 V + OUT B –IN A 4 13 OUT B –IN B +IN A 5 12 –IN B +IN B V– 11 +IN B OUT A 1 8 V+ –IN A 2 7 +IN A 3 6 5 V– 4 ORDER PART NUMBER TOP VIEW LTC1047CN8 N8 PACKAGE 8-LEAD PDIP TJMAX = 110°C, θJA = 130°C/W 6 NC 7 10 NC NC 8 9 LTC1047CSW NC SW PACKAGE 16-LEAD PLASTIC SO WIDE TJMAX = 110°C, θJA = 200°C/W 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, unless otherwise noted. PARAMETER CONDlTlONS Input Offset Voltage TA = 25°C (Note 3) Average Input Offset Voltage Drift (Note 3) MIN ● TYP MAX UNITS ±3 ±10 µV ±0.01 ±0.05 µV/°C Long Term Offset Drift 100 Input Bias Current ±5 ±30 ±300 pA pA ±10 ±60 ±150 pA pA ● Input Offset Current ● nV√mo Input Noise Voltage 0.1Hz to 10Hz 0.1Hz to 1Hz 3.5 0.8 µVP-P µVP-P Input Noise Current f = 10Hz (Note 4) 1.5 fA√Hz Common Mode Rejection Ratio VCM Power Supply Rejection Ratio = V – to 2.7V, T A = 25°C ● 110 105 130 dB dB VS = ±2.375V to ±8V ● 105 122 dB Large-Signal Voltage Gain RL = 100k, VOUT = ±4V ● 120 150 dB Maximum Output Voltage Swing RL = 10k RL = 100k ● 4.8/–4.9 4.3/–4.8 ±4.95 V V 1047fa 2 LTC1047 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±5V, unless otherwise noted. PARAMETER CONDlTlONS Slew Rate RL = 100k, CL = 50pF MIN Gain Bandwidth Product Supply Current/Amplifier No Load, 25°C ≤ TA ≤ 70°C No Load, 0°C ≤ TA ≤ 25°C TYP MAX V/µs 200 kHz 60 80 Internal Sampling Frequency 150 275 680 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 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 LTC1047. UNITS 0.2 µA µA Hz Note 3: These parameters are guaranteed by design. Thermocouple effects preclude measurements 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. U W TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Supply Voltage Per Amplifier 120 Supply Current vs Temperature Per Amplifier 90 TA = 25°C SUPPLY CURRENT, IS (µA) SUPPLY CURRENT, IS (µA) 100 80 60 40 20 0 4 VS = ±5V 80 70 60 50 40 50 25 –50 –25 0 75 100 AMBIENT TEMPERATURE, TA (°C) 14 16 8 10 12 6 TOTAL SUPPLY VOLTAGE, V + TO V – (V) LTC1047 • TPC03 LTC1047 • TPC02 Output Short-Circuit Current vs Supply Voltage SHORT CIRCUIT OUTPUT CURRENT, IOUT (mA) Common Mode Input Range vs Supply Voltage 8 VCM = V – COMMON MODE RANGE (V) 6 4 2 0 –2 –4 –6 –8 0 1 4 5 2 3 6 SUPPLY VOLTAGE (±V) 125 7 8 LTC1047 • TPC04 3 2 VOUT = V – ISOURCE 1 0 VOUT = V + ISINK –4 –8 –12 4 14 16 8 10 12 6 TOTAL SUPPLY VOLTAGE, V + TO V – (V) LTC1047 • TPC05 1047fa 3 LTC1047 U W TYPICAL PERFOR A CE CHARACTERISTICS CMRR vs Frequency PSRR vs Frequency 120 160 VS = ±5V TA = 25°C 140 100 120 PSRR (dB) CMRR (dB) 80 100 80 60 NEGATIVE SUPPLY 60 40 40 POSITIVE SUPPLY 20 20 0 0 1 10 100 1k FREQUENCY (Hz) 10k 1 100k 10 100 1k FREQUENCY (Hz) Sampling Frequency vs Supply Voltage Gain, Phase vs Frequency, ±5V 90 135 40 GAIN 20 180 0 225 104 105 FREQUENCY (Hz) 106 270 SAMPLING FREQUENCY, fS (Hz) PHASE PHASE SHIFT (DEGREES) GAIN (dB) 900 45 80 VS = ±5V CL = 50pF –20 103 102 TA = 25°C 800 700 600 500 4 6 8 10 12 14 16 TOTAL SUPPLY VOLTAGE, V + TO V – (V) LTC1047 • TPC09 LTC1047 • TPC08 Sampling Frequency vs Temperature SAMPLING FREQUENCY, fS (Hz) 1000 100k LTC1047 • TPC07 LTC1047 • TPC06 60 10k Small-Signal Transient Response VS = ±5V 900 100mV STEP 800 700 600 500 50 25 0 75 100 –50 –25 AMBIENT TEMPERATURE, TA (°C) 125 AV = +1 RL = 100k CL = 50pF VS = ±5V 10µs/DIV LTC1047 • TPC11 LTC1047 • TPC010 1047fa 4 LTC1047 U W TYPICAL PERFOR A CE CHARACTERISTICS Overload Recovery Large-Signal Transient Response 0 Photo –5V 200mV 0 AV = +1 RL = 100k CL = 50pF VS = ±5V AV = 100 VS = ±5V 10µs/DIV 10ms/DIV LTC1047 • TPC13 LTC1047 • TPC12 TEST CIRCUITS Electrical Characteristics Test Circuit 1M 1k V+ 2 3 – 8 1/2 LTC1047 + 4 6 OUTPUT RL V– LTC1047 • TC01 DC to 10Hz Noise Test Circuit 100k 10Ω 475k 0.01µF 2 3 – 1/2 LTC1047 6 158k 316k 475k – LT®1012 + 0.01µF 0.01µF OUTPUT + FOR 1Hz NOISE BANDWIDTH, INCREASE ALL CAPACITORS BY A FACTOR OF 10 LTC1047 • TC02 1047fa 5 LTC1047 U W U U APPLICATIO S I FOR ATIO Input Considerations Aliasing Frequently circuits built with parts as precise as the LTC1047 show errors at the output far greater than the designer expects. Rarely is the problem the op amp; more often the surrounding circuitry is causing errors several orders of magnitude greater than those due to the LTC1047. Such obscure effects as leakage between pins, due to residual solder flux and thermocouple effects between the tin/lead solder and the copper PC board traces, can overwhelm the pA-level bias currents and the µV-level offset of the LTC1047. For a more complete description of these types of problems (and some advice on avoiding them), see the LTC1051/LTC1053 data sheet. Like all sampled data systems, the LTC1047 will alias input signals near its internal sampling frequency. The design includes internal circuitry to minimize this effect; as a result, most applications do not exhibit aliasing problems. For a complete discussion of the correction circuitry and aliasing behavior, refer to the LTC1051/LTC1053 data sheet. Input Capacitance The LTC1047 has approximately 12pF of capacitance at each input pin. This will react with large series resistors to form a pole at the input, degrading the LTC1047's phase margin. The problem is especially common with micropower parts like the LTC1047 because high value resistors are often used to minimize power dissipation. As a rule of thumb, bypass feedback resistors larger than 7k with a 20pF capacitor to minimize this effect. Single Supply Operation The LTC1047 is compatible with all single supply applications. It has an input common mode range which includes V –, and an output which will swing within millivolts of the negative power supply. The LTC1047 is guaranteed functional down to 4.75V total supply, allowing it to run from minimum TTL voltage all the way up to 16V. See the Typical Applications section for examples of single supply operation. 1047fa 6 LTC1047 U TYPICAL APPLICATIO S Low Offset, Low Drift Instrumentation Amplifier 1M 1k 1k 1M 5V 2 –IN 3 6 – 1 1/2 LTC1047 + +IN 4 AV = 1000 VOS = ± 6µV IS = 100µA CMRR ≥ 120dB –5V 5 8 – 1/2 LTC1047 7 OUTPUT + LTC1047 • TA02 Precise DC Full-Wave Rectifier (Absolute Value Circuit) 220k 5V 220k INPUT 2 0V 3 IS = 50µA VOS = 3µV – 8 1/2 LTC1047 + 4 1N4148 1 5 6 + 1/2 LTC1047 7 OUTPUT – LTC1047 • TA03 1047fa 7 LTC1047 U TYPICAL APPLICATIO S 4mA to 20mA Transducer Amplifier 4 5 LT1120 0.1µF 1M 1000pF 2 8 1 3 7 6 1M TO LOOP + 10µF 2 – 1/2 3 LTC1047 1 R2 61.9k 1% + INPUT 0V TO 1V INITIAL ACCURACY = 3% (LIMITED BY REFERENCE IN LT1120) TRIM R1 FOR 4.00mA WITH 0.00V IN TRIM R2 FOR 20.0mA WITH 1.00V IN R1 619K 1% 5 49.9k 1% 6 + 8 1/2 LTC1047 – 7 1k 2N2222 4 49.9Ω 1% TO LOOP LTC1047 • TA04 1047fa 8 LTC1047 U TYPICAL APPLICATIO S Ultralow Noise Micropower Chopper 0.47µF 5V 5V 5V 0.1µF 75k – 1/2 LTC1047 + 100k 39k + 1/2 LTC1047 20k OUT – 100k +IN 50pF 0.1µF –IN –5V 100k 25K147 x 2 10Ω 150k 100k IS = 150µA 0.1Hz TO 10Hz = 95nVP-P AV = 10000 –5V LTC1047 • TA06 0.47µF 0.1Hz to 10Hz Noise (Input Referred) 200nV VS = ±5V IS = 150µA 100nV 50nV/DIV –100nV –200nV 0 TIME (SEC) 10 LTC1047 • TA07 1047fa 9 LTC1047 U PACKAGE DESCRIPTIO N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) .045 – .065 (1.143 – 1.651) .130 ± .005 (3.302 ± 0.127) .065 (1.651) TYP .100 (2.54) BSC .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) 1047fa 10 LTC1047 U PACKAGE DESCRIPTIO SW Package 16-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .398 – .413 (10.109 – 10.490) NOTE 4 16 N 15 14 13 12 11 10 9 N .325 ±.005 .420 MIN .394 – .419 (10.007 – 10.643) NOTE 3 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT 1 .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 3 4 5 6 7 .093 – .104 (2.362 – 2.642) 8 .037 – .045 (0.940 – 1.143) 0° – 8° TYP NOTE 3 .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 2 .050 (1.270) BSC .004 – .012 (0.102 – 0.305) .014 – .019 (0.356 – 0.482) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) S16 (WIDE) 0502 1047fa 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. 11 LTC1047 U TYPICAL APPLICATIO Low Noise, Low Drift Composite Amplifier 5V 5 10k 6 8 + 1/2 LTC1047 7 – 0.01µF 100k 2 3 – 1/2 LTC1047 + 5V 4 750Ω –5V INPUT 1000pF 1 3 + – 2 100k 56Ω 250k 1 + 7 8 LT ®1012 – 6 4 –5V VOS = 3µV 0.1Hz TO 10Hz NOISE = 0.7µVP-P IS = 490µA 100Ω OUTPUT LTC1047 • TA05 1047fa 12 Linear Technology Corporation LW/TP 1202 1K 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 1992