LT1677IS8

LT1677 Low Noise, Rail-to-Rail Precision Op Amp U FEATURES DESCRIPTIO ■ The LT ®1677 features the lowest noise performance available for a rail-to-rail operational amplifier: 3.2nV/√Hz wideband noise, 1/f corner frequency of 13Hz and 90nV peak-to-peak 0.1Hz to 10Hz noise. Low noise is combined with outstanding precision: 20µV offset voltage and 0.2µV/°C drift, 130dB common mode and power supply rejection and 7.2MHz gain bandwidth product. The common mode range exceeds the power supply by 100mV. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Rail-to-Rail Input and Output 100% Tested Low Voltage Noise: 3.2nV/√Hz Typ at 1kHz 4.5nV/√Hz Max at 1kHz Offset Voltage: 60µV Max Low VOS Drift: 0.2µV/°C Typ Low Input Bias Current: 20nA Max Wide Supply Range: 3V to ±18V High AVOL: 7V/µV Min, RL = 10k High CMRR: 109dB Min High PSRR: 108dB Min Gain Bandwidth Product: 7.2MHz Slew Rate: 2.5V/µs Operating Temperature Range: – 40°C to 85°C The voltage gain of the LT1677 is extremely high, 19 million (typical) driving a 10k load. In the design, processing and testing of the device, particular attention has been paid to the optimization of the entire distribution of several key parameters. Consequently, the specifications have been spectacularly improved compared to competing rail-to-rail amplifiers. U APPLICATIO S ■ ■ ■ ■ ■ ■ ■ , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Low Noise Signal Processing Microvolt Accuracy Threshold Detection Strain Gauge Amplifiers Tape Head Preamplifiers Direct Coupled Audio Gain Stages Infrared Detectors Battery-Powered Microphones U TYPICAL APPLICATIO Distribution of Offset Voltage 25 3V Electret Microphone Amplifier TA = 25°C VS = ±15V PANASONIC ELECTRET CONDENSER MICROPHONE WM-61 www.panasonic.com/pic (714) 373-7334 R1 10k R3 1M AV = –100 C1 0.68µF R2 10k 23Hz HIGHPASS 1.5V 2 3 – + 7 LT1677 6 TO PA OR HEADPHONES 4 –1.5V PERCENT OF UNITS 20 1.5V 15 10 5 1677 TA01 0 –40 –30 –20 –10 0 10 20 30 INPUT OFFSET VOLTAGE (µV) 40 1677 TA02 1677fa 1 LT1677 W W W AXI U U ABSOLUTE RATI GS U U W PACKAGE/ORDER I FOR ATIO (Note 1) Supply Voltage ...................................................... ±22V Input Voltages (Note 2) ............ 0.3V Beyond Either Rail Differential Input Current (Note 2) ..................... ± 25mA Output Short-Circuit Duration (Note 3) ............ Indefinite Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec.)................. 300°C Operating Temperature Range LT1677C (Note 4) ............................. – 40°C to 85°C LT1677I ............................................. – 40°C to 85°C Specified Temperature Range LT1677C (Note 5) ............................. – 40°C to 85°C LT1677I ............................................. – 40°C to 85°C TOP VIEW VOS 1 TRIM –IN 2 – VOS TRIM 7 +VS +IN 3 + 6 OUT 8 5 NC –VS 4 N8 PACKAGE 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/ W (N8) TJMAX = 150°C, θJA = 190°C/ W (S0-8) S8 PART MARKING 1677 1677I ORDER PART NUMBER LT1677CS8 LT1677IS8 LT1677CN8 LT1677IN8 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 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 3V, VCM = VO = 1.7V; VS = 5V, VCM = VO = 2.5V unless otherwise noted. SYMBOL PARAMETER VOS Input Offset Voltage (Note 11) ∆VOS ∆Temp ∆VOS ∆Time IB IOS Average Input Offset Drift (Note 10) CONDITIONS (Note 6) MIN Input Offset Current (Note 11) MAX UNITS 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 35 55 75 90 150 210 µV µV µV VCM = VS + 0.1V VCM = VS – 0.2V, 0°C ≤ TA ≤ 70°C VCM = VS – 0.3V, – 40°C ≤ TA ≤ 85°C ● ● 150 180 200 400 550 650 µV µV µV VCM = – 0.1V VCM = 0V, 0°C ≤ TA ≤ 70°C VCM = 0V, – 40°C ≤ TA ≤ 85°C ● ● 1.5 1.8 2.0 5.0 6.0 6.5 mV mV mV SO-8 N8 ● ● 0.40 0.20 2.0 1.5 µV/°C µV/°C Long Term Input Voltage Stability Input Bias Current (Note 11) TYP µV/Mo 0.3 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● ±2 ±3 ±7 ±20 ±35 ±50 nA nA nA VCM = VS + 0.1V VCM = VS – 0.2V, 0°C ≤ TA ≤ 70°C VCM = VS – 0.3V, – 40°C ≤ TA ≤ 85°C ● ● 0.19 0.19 0.25 0.40 0.60 0.75 µA µA µA VCM = – 0.1V VCM = 0V, 0°C ≤ TA ≤ 70°C VCM = 0V, – 40°C ≤ TA ≤ 85°C ● ● 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 4 5 8 15 20 40 nA nA nA VCM = VS + 0.1V VCM = VS – 0.2V, 0°C ≤ TA ≤ 70°C VCM = VS – 0.3V, – 40°C ≤ TA ≤ 85°C ● ● 6 10 15 30 40 65 nA nA nA VCM = – 0.1V VCM = 0V, 0°C ≤ TA ≤ 70°C VCM = 0V, – 40°C ≤ TA ≤ 85°C ● ● 20 25 30 100 150 160 nA nA nA – 1.2 –2.0 –2.3 µA µA µA – 0.41 – 0.45 – 0.47 1677fa 2 LT1677 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 3V, VCM = VO = 1.7V; VS = 5V, VCM = VO = 2.5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS (Note 6) en Input Noise Voltage 0.1Hz to 10Hz (Note 7) VCM = VS VCM = 0V 90 180 600 nVP-P nVP-P nVP-P Input Noise Voltage Density (Note 8) fO = 10Hz VCM = VS, fO = 10Hz VCM = 0V, fO = 10Hz 5.2 7 25 nV/√Hz nV/√Hz nV/√Hz fO = 1kHz VCM = VS, fO = 1kHz VCM = 0V, fO = 1kHz 3.2 5.3 17 fO = 10Hz fO = 1kHz 1.2 0.3 in Input Noise Current Density VCM Input Voltage Range RIN 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C Input Resistance CIN Input Capacitance CMRR Common Mode Rejection Ratio (Note 11) PSRR AVOL Power Supply Rejection Ratio Large-Signal Voltage Gain MIN ● ● TYP – 0.1 0 0 Common Mode MAX 4.5 UNITS nV/√Hz nV/√Hz nV/√Hz pA/√Hz pA/√Hz VS + 0.1V VS – 0.2V VS – 0.3V V V V 2 GΩ 4.2 pF VS = 3V VCM = –0.1V to 3.1V VCM = 0V to 2.7V ● 55 53 68 67 dB dB VS = 5V VCM = –0.1V to 5.1V VCM = 0V to 4.7V ● 60 58 73 72 dB dB VS = 2.7V to 40V, VCM = VO = 1.7V VS = 3.1V to 40V, VCM = VO = 1.7V ● 108 105 125 120 dB dB VS = 3V, RL ≥ 10k, VO = 2.5V to 0.7V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 0.6 0.4 0.4 4 3 3 V/µV V/µV V/µV VS = 3V, RL ≥ 2k, VO = 2.2V to 0.7V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 0.5 0.4 0.4 1 0.9 0.8 V/µV V/µV V/µV VS = 3V, RL ≥ 600Ω, VO = 2.2V to 0.7V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 0.20 0.15 0.10 0.43 0.40 0.35 V/µV V/µV V/µV VS = 5V, RL ≥ 10k, VO = 4.5V to 0.7V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 0.8 0.7 0.7 5 4 4 V/µV V/µV V/µV VS = 5V, RL ≥ 2k, VO = 4.2V to 0.7V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 0.40 0.35 0.25 0.9 0.8 0.6 V/µV V/µV V/µV VS = 5V, RL ≥ 600Ω, VO = 4.2V to 0.7V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 0.35 0.30 0.20 0.67 0.60 0.45 V/µV V/µV V/µV 1677fa 3 LT1677 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 3V, VCM = VO = 1.7V; VS = 5V, VCM = VO = 2.5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS (Note 6) VOL Output Voltage Swing Low (Note 11) Above GND ISINK = 0.1mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C VOH ISC SR GBW Output Voltage Swing High (Note 11) Output Short-Circuit Current (Note 3) Slew Rate (Note 13) Gain Bandwidth Product (Note 11) MIN TYP MAX UNITS ● ● 110 125 130 170 200 230 mV mV mV Above GND ISINK = 2.5mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 170 195 205 250 320 350 mV mV mV Above GND ISINK = 10mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 370 440 465 500 600 650 mV mV mV Below VS ISOURCE = 0.1mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 75 85 93 170 200 250 mV mV mV Below VS ISOURCE = 2.5mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 170 195 205 300 350 375 mV mV mV Below VS ISOURCE = 10mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 450 510 525 700 800 850 mV mV mV VS = 3V 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 15 14 13 22 20 19 mA mA mA VS = 5V 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 20 18 17 29 27 25 mA mA mA AV = – 1 RL ≥ 10k, 0°C ≤ TA ≤ 70°C RL ≥ 10k, – 40°C ≤ TA ≤ 85°C ● ● 1.7 1.5 1.2 2.5 2.3 2.0 V/µs V/µs V/µs fO = 100kHz fO = 100kHz, 0°C ≤ TA ≤ 70°C fO = 100kHz, – 40°C ≤ TA ≤ 85°C ● ● 4.5 3.8 3.7 7.2 6.2 5.8 MHz MHz MHz tS Settling Time 2V Step 0.1%, AV = +1 2V Step 0.01%, AV = +1 2.1 3.5 µs µs RO Open-Loop Output Resistance Closed-Loop Output Resistance IOUT = 0 AV = 100, f = 10kHz 80 1 Ω Ω IS Supply Current (Note 12) 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 2.60 2.75 2.80 3.4 3.7 3.8 mA mA mA 1677fa 4 LT1677 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = VO = 0V unless otherwise noted. SYMBOL PARAMETER VOS Input Offset Voltage ∆VOS ∆Temp Average Input Offset Drift (Note 10) ∆VOS ∆Time Long Term Input Voltage Stability IB Input Bias Current IOS en CONDITIONS (Note 6) MIN TYP MAX UNITS 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 20 30 45 60 120 180 µV µV µV VCM = 15.1V VCM = 14.8V, 0°C ≤ TA ≤ 70°C VCM = 14.7V, – 40°C ≤ TA ≤ 85°C ● ● 150 180 200 400 550 650 µV µV µV VCM = – 15.1V VCM = –15V, 0°C ≤ TA ≤ 70°C VCM = –15V, – 40°C ≤ TA ≤ 85°C ● ● 1.5 1.8 2.0 5.0 6.0 6.5 mV mV mV SO-8 N8 ● ● 0.40 0.20 2.0 1.5 µV/°C µV/°C µV/Mo 0.3 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● ±2 ±3 ±7 ±20 ±35 ±50 nA nA nA VCM = 15.1V VCM = 14.8V, 0°C ≤ TA ≤ 70°C VCM = 14.7V, – 40°C ≤ TA ≤ 85°C ● ● 0.19 0.20 0.25 0.40 0.60 0.75 µA µA µA VCM = –15.1V VCM = –15V, 0°C ≤ TA ≤ 70°C VCM = –15V, – 40°C ≤ TA ≤ 85°C ● ● 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 3 5 8 15 20 40 nA nA nA VCM = 15.1V VCM = 14.8V, 0°C ≤ TA ≤ 70°C VCM = 14.7V, – 40°C ≤ TA ≤ 85°C ● ● 5 8 12 25 35 60 nA nA nA VCM = –15.1V VCM = –15V, 0°C ≤ TA ≤ 70°C VCM = –15V, – 40°C ≤ TA ≤ 85°C ● ● 20 25 30 105 160 170 nA nA nA – 1.2 –2.0 –2.3 Input Offset Current µA µA µA – 0.42 – 0.46 – 0.48 Input Noise Voltage 0.1Hz to 10Hz (Note 7) VCM = 15V VCM = –15V 90 180 600 nVP-P nVP-P nVP-P Input Noise Voltage Density fO = 10Hz VCM = 15V, fO = 10Hz VCM = –15V, fO = 10Hz 5.2 7 25 nV/√Hz nV/√Hz nV/√Hz fO = 1kHz VCM = 15V, fO = 1kHz VCM = –15V, fO = 1kHz 3.2 5.3 17 fO = 10Hz fO = 1kHz 1.2 0.3 in Input Noise Current Density VCM Input Voltage Range 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C RIN Input Resistance CIN Input Capacitance Common Mode ● ● – 15.1 – 15.0 – 15.0 4.5 nV/√Hz nV/√Hz nV/√Hz pA/√Hz pA/√Hz 15.1 14.8 14.7 V V V 2 GΩ 4.2 pF 1677fa 5 LT1677 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = VO = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS (Note 6) MIN TYP CMRR Common Mode Rejection Ratio VCM = –13.3V to 14V ● 109 105 130 124 dB dB ● 74 72 95 91 dB dB ● 106 103 130 125 dB dB VS = 2.7V to 40V VS = 3.1V to 40V ● 108 105 125 120 dB dB RL ≥ 10k, VO = ±14V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 7 4 3 19 13 8 V/µV V/µV V/µV RL ≥ 2k, VO = ±13.5V 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C ● ● 0.50 0.30 0.15 0.75 0.67 0.24 V/µV V/µV V/µV 0.2 0.5 V/µV VCM = –15.1V to 15.1V VCM = –15V to 14.7V PSRR AVOL Power Supply Rejection Ratio Large-Signal Voltage Gain VS = ±1.7V to ±18V RL ≥ 600Ω, VO = ±10V VOL VOH ISC SR GBW Output Voltage Swing Low Output Voltage Swing High Gain Bandwidth Product UNITS Above – VS ISINK = 0.1mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 110 125 130 170 200 230 mV mV mV Above – VS ISINK = 2.5mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 170 195 205 250 320 350 mV mV mV Above – VS ISINK = 10mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 370 440 450 500 600 650 mV mV mV Below +VS ISOURCE = 0.1mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 110 130 140 170 200 250 mV mV mV Below +VS ISOURCE = 2.5mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 210 240 250 300 350 375 mV mV mV Below +VS ISOURCE = 10mA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 520 590 620 700 800 850 mV mV mV 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 25 20 18 35 30 28 mA mA mA RL ≥ 10k (Note 9) RL ≥ 10k (Note 9) 0°C ≤ TA ≤ 70°C RL ≥ 10k (Note 9) – 40°C ≤ TA ≤ 85°C ● ● 1.7 1.5 1.2 2.5 2.3 2.0 V/µs V/µs V/µs fO = 100kHz fO = 100kHz, 0°C ≤ TA ≤ 70°C fO = 100kHz, – 40°C ≤ TA ≤ 85°C ● ● 4.5 3.8 3.7 7.2 6.2 5.8 MHz MHz MHz Output Short-Circuit Current (Note 3) Slew Rate MAX 1677fa 6 LT1677 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = VO = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS (Note 6) THD Total Harmonic Distortion RL = 2k, AV = 1, fO = 1kHz, VO = 10VP-P MIN tS Settling Time RO Open-Loop Output Resistance Closed-Loop Output Resistance IS Supply Current TYP MAX UNITS 0.0006 % 10V Step 0.1%, AV = +1 10V Step 0.01%, AV = +1 5 6 µs µs IOUT = 0 AV = 100, f = 10kHz 80 1 Ω Ω 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C 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: The inputs are protected by back-to-back diodes. Current limiting resistors are not used in order to achieve low noise. If differential input voltage exceeds ±1.4V, the input current should be limited to 25mA. If the common mode range exceeds either rail, the input current should be limited to 10mA. Note 3: A heat sink may be required to keep the junction temperature below absolute maximum. Note 4: The LT1677C and LT1677I are guaranteed functional over the Operating Temperature Range of – 40°C to 85°C. Note 5: The LT1677C is guaranteed to meet specified performance from 0°C to 70°C. The LT1677C 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 LT1677I is guaranteed to meet specified performance from – 40°C to 85°C. 2.75 3.00 3.10 ● ● 3.5 3.9 4.0 mA mA mA Note 6: Typical parameters are defined as the 60% yield of parameter distributions of individual amplifier; i.e., out of 100 LT1677s, typically 60 op amps will be better than the indicated specification. Note 7: See the test circuit and frequency response curve for 0.1Hz to 10Hz tester in the Applications Information section of the LT1677 data sheet. Note 8: Noise is 100% tested at ±15V supplies. Note 9: Slew rate is measured in AV = – 1; input signal is ±7.5V, output measured at ±2.5V. Note 10: This parameter is not 100% tested. VS = 3V and 5V limits are guaranteed by correlation to VS = ±15V test. Note 11: VS = 5V limits are guaranteed by correlation to VS = 3V and VS = ±15V tests. Note 12: VS = 3V limits are guaranteed by correlation to VS = 5V and VS = ±15V tests. Note 13: Guaranteed by correlation to slew rate at VS = ±15V and GBW at VS = 3V and VS = ±15V tests. U W TYPICAL PERFOR A CE CHARACTERISTICS Voltage Noise vs Frequency 0.1Hz to 10Hz Voltage Noise 0.01Hz to 1Hz Voltage Noise VCM < –14.5V 1/f CORNER 8.5Hz 10 VCM –13.5V TO 14.5V VOLTAGE NOISE (20nV/DIV) 1/f CORNER 10Hz VOLTAGE NOISE (20nV/DIV) RMS VOLTAGE NOISE DENSITY (nV/√Hz) 100 VCM > 14.5V 1/f CORNER 13Hz VS = ±15V TA = 25°C 1 0.1 1 10 100 FREQUENCY (Hz) 1000 1677 G01 0 2 4 6 TIME (SECONDS) 8 10 1677 G03 0 20 40 60 TIME (SECONDS) 80 100 1677 G04 1677fa 7 LT1677 U W TYPICAL PERFOR A CE CHARACTERISTICS Voltage Noise vs Temperature 6 10Hz 5 4 1kHz 3 10 VS = ±15V 9 VCM = 0V VS = ±15V TA = 25°C VCM < –13.5V 1/f CORNER 180Hz 1 VCM –13.5V TO 14.5V 1/f CORNER 90Hz 1/f CORNER 60Hz 50 25 0 75 TEMPERATURE (°C) 100 100 1000 FREQUENCY (Hz) 10 125 600 VCM = 14.7V CURRENT INTO DUT 200 VS = ±15V TA = 25°C 50 25 0 75 TEMPERATURE (°C) 100 125 400 VCM = –13.6V 200 VCM = 15.15V INPUT BIAS CURRENT 0 VCM = 14.3V –200 VCM = –15.3V –400 200 16 40 6 N PACKAGE 1.0 100 0.5 50 0 0 –0.5 –50 –1.0 –100 –1.5 –150 VS = ±1.5V TO ±15V TA = 25°C –200 5 TYPICAL PARTS –250 2.0 –0.8 –0.4 V + 0.4 –2.5 –1.0 V– 1.0 VCM – V – (V) VCM – V + (V) 1677 G10 Distribution of Input Offset Voltage Drift (SO-8) 30 VS = ±15V TA = –40°C TO 85°C 167 PARTS (4 LOTS) 35 30 25 20 15 10 2 150 VOS IS REFERRED TO VCM = 0V 25 PERCENT OF UNITS (%) 45 PERCENT OF UNITS (%) CHANGE IN OFFSET VOLTAGE (µV) 50 8 4 250 Distribution of Input Offset Voltage Drift (N8) VS = ±15V TA = 25°C 125 100 2.5 1677 G09 Warm-Up Drift SO PACKAGE 50 25 0 75 TEMPERATURE (°C) 2.0 –2.0 –800 0 4 –16 –12 –8 –4 8 12 COMMON MODE INPUT VOLTAGE (V) 1677 G06 10 2 1.5 –600 100 –50 –25 3 Offset Voltage Shift vs Common Mode OFFSET VOLTAGE (mV) INPUT BIAS CURRENT (nA) 300 4 OFFSET VOLTAGE (µV) INPUT BIAS CURRENT (nA) 800 VS = ±15V 400 5 1677 G05 Input Bias Current Over the Common Mode Range VCM = –14V CURRENT OUT OF DUT 6 1677 G07 Input Bias Current vs Temperature 500 7 0 –50 –25 10000 1677 G08 600 8 1 VCM > 14.5V 0.1 2 –50 –25 INPUT BIAS CURRENT (nA) 10 VS = ±15V VCM = 0V RMS CURRENT NOISE DENSITY (pA/√Hz) RMS VOLTAGE NOISE DENSITY (nV/√Hz) 7 Input Bias Current vs Temperature Current Noise vs Frequency VS = ±15V TA = –40°C TO 85°C 201 PARTS (5 LOTS) 20 15 10 5 5 0 0 1 3 2 TIME (MINUTES) 4 5 1677 G02 0 –1.0 –0.6 –0.2 0.2 0.6 1.0 1.4 INPUT OFFSET VOLTAGE DRIFT (µV/°C) 1677 G13 0 –0.8 –0.4 0 0.4 0.8 1.2 1.6 2.0 INPUT OFFSET VOLTAGE DRIFT (µV/°C) 1677 G37 1677fa 8 LT1677 U W TYPICAL PERFOR A CE CHARACTERISTICS Common Mode Range vs Temperature VOS vs Temperature of Representative Units OFFSET VOLTAGE (mV) 80 5 2.0 200 4 1.5 150 60 40 20 0 –20 VS = ±2.5V TO ±15V 125°C 1.0 0.5 100 25°C –55°C 0 0 –0.5 –50 VOS IS REFERRED 125°C TO VCM = 0V –1.0 –100 25°C 3 2 1 0 –1 –2 –3 –40 –1.5 –150 –60 –2.0 –200 –4 –80 –55 –35 –15 –2.5 –1.0 –250 –5 V– 2.0 –0.8 –0.4 1.0 VCM – VS– (V) V+ 160 COMMON MODE REJECTION RATIO (dB) TA = –55°C 2 1 ±5 ±10 ±15 SUPPLY VOLTAGE (V) 0 VS = ±15V TA = 25°C VCM = 0V 140 120 100 80 60 40 20 10k 100k 1M FREQUENCY (Hz) 60 VCM = 0V VCM = VCC 20 –20 0.01 10k 100 FREQUENCY (Hz) 1M NEGATIVE SUPPLY 80 POSITIVE SUPPLY 60 40 20 10M 100 100M 1677 G18 1 10 100 10k 1k FREQUENCY (Hz) 100k 1677 G17 60 TA = 25°C RL TO GND VCM: VO = VS/2 50 RL = 10k 10 RL = 2k 1 VS = ±15V TA = 25°C RL = 10k TO 2k 40 RISING EDGE 30 20 FALLING EDGE 10 0 10 20 SUPPLY VOLTAGE (V) 1M Overshoot vs Load Capacitance 0.1 1 100 1677 G16 OPEN LOOP VOLTAGE GAIN (V/µV) 140 VCM = VEE 120 Voltage Gain vs Supply Voltage (Single Supply) VS = ±15V TA = 25°C VS = ±15V TA = 25°C 140 0 1k Voltage Gain vs Frequency 100 160 0 ±20 1677 G15 180 Power Supply Rejection Ratio vs Frequency OVERSHOOT (%) SUPPLY CURRENT (mA) TA = 25°C 1677 G14 Common Mode Rejection Ratio vs Frequency 4 TA = 125°C 0 100 200 300 400 500 600 700 800 900 TIME (HOURS) 1677 G12 Supply Current vs Supply Voltage 3 0.4 VCM – VS+ (V) POWER SUPPLY REJECTION RATIO (dB) 5 25 45 65 85 105 125 TEMPERATURE (°C) 1677 G11 VOLTAGE GAIN (dB) 50 –55°C OFFSET VOLTAGE (µV) VOLTAGE OFFSET (µV) 100 250 2.5 VS = ±15V VCM = 0V SO-8 N8 120 OFFSET VOLTAGE CHANGE (µV) 140 Long-Term Stability of Four Representative Units 30 1677 G19 0 10 100 CAPACITANCE (pF) 1000 1677 G21 1677fa 9 LT1677 U W TYPICAL PERFOR A CE CHARACTERISTICS Large-Signal Transient Response GAIN BANDWIDTH PRODUCT, fO = 100kHz (MHz) PHASE MARGIN (DEG) PM, GBWP, SR vs Temperature 70 VS = ±15V CL = 15pF PHASE 60 8 GBW 7 50 6 5 SLEW RATE (V/µs) 3 4 SLEW 2 1 –50 –25 50 25 0 75 TEMPERATURE (°C) Small-Signal Transient Response 50mV 10V 0 – 10V – 50mV AVCL = – 1 VS = ±15V 5µs/DIV AVCL = 1 VS = ±15V CL = 15pF 0.5µs/DIV 125 100 1677 G22 Settling Time vs Output Step (Noninverting) 0.1% OF FULL SCALE 0.01% OF FULL SCALE 0.1% OF FULL SCALE 4 2 10 VOUT + 8 6 VIN 8 6 – 2k VIN RL = 1k 6 0.01% OF FULL SCALE 4 PHASE 10 20 0 0 –10 0.1 1 10 FREQUENCY (MHz) –20 100 1677 G35 50 20 0 0 0.1 10 –20 100 1 10 FREQUENCY (MHz) 1677 G34 Output Voltage Swing vs Load Current 100 VS = ±15V VCM = –14V CL = 10pF 80 125°C 25°C – 55°C 60 40 VOLTAGE GAIN (dB) VOLTAGE GAIN (dB) GAIN 8 30 20 40 GAIN PHASE 10 20 0 0 –10 0.1 1 10 FREQUENCY (MHz) PHASE SHIFT (DEG) 40 PHASE SHIFT (DEG) 20 PHASE 10 Gain, Phase Shift vs Frequency 100 VS = ±15V VCM = 14.7V CL = 10pF 80 125°C 25°C – 55°C 60 30 40 GAIN 1677 G26 Gain, Phase Shift vs Frequency 40 20 –10 6 1677 G25 50 30 0.1% OF FULL SCALE 0 –10 –8 –6 –4 –2 0 2 4 OUTPUT STEP (V) 10 40 VOUT + 8 0.01% OF FULL SCALE 100 VS = ±15V VCM = 0V CL = 10pF 80 125°C 25°C – 55°C 60 2k 0.1% OF 2 FULL SCALE VS = ±15V AV = –1 TA = 25°C 0 –10 –8 –6 –4 –2 0 2 4 OUTPUT STEP (V) 50 VS = ±15V AV = 1 TA = 25°C 5k – PHASE SHIFT (DEG) SETTLING TIME (µs) 10 12 5k –20 100 1677 G36 +VS – 0 VS = ±15V –0.1 –0.2 –0.3 –0.4 –0.5 –0.6 –0.7 0.5 125°C 0.4 25°C 0.3 OUTPUT VOLTAGE SWING (V) 0.01% OF FULL SCALE SETTLING TIME (µs) 12 Gain, Phase Shift vs Frequency VOLTAGE GAIN (dB) Settling Time vs Output Step (Inverting) –55°C 25°C 125°C 0.2 –55°C 0.1 –VS + 0 –10 –8 –6 –4 –2 0 2 4 6 8 ISOURCE ISINK OUTPUT CURRENT (mA) 10 1677 G27 1677fa 10 LT1677 U W TYPICAL PERFOR A CE CHARACTERISTICS SHORT-CIRCUIT CURRENT (mA) SINKING SOURCING 1 AV = +100 0.1 AV = +1 0.01 100 10 10k 1k FREQUENCY (Hz) –55°C 30 25°C 20 125°C 10 –30 –35 125°C –40 –55°C –45 1M 0 AV = –100 0.001 AV = –10 AV = –1 0.0001 20 100 1k FREQUENCY (Hz) 10k 20k 1677 G31 0.01 AV = 100 0.001 AV = 10 AV = 1 3 2 4 1 TIME FROM OUTPUT SHORT TO GND (MIN) 20 100 1k FREQUENCY (Hz) 10k 20k 1677 G30 Total Harmonic Distortion and Noise vs Output Amplitude for Noninverting Gain TOTAL HARMONIC DISTORTION + NOISE (%) TOTAL HARMONIC DISTROTION + NOISE (%) ZL = 2k/15pF VS = ±15V VO = 10VP-P AV = –1, –10, – 100 MEASUREMENT BANDWIDTH = 10Hz TO 80kHz ZL = 2k/15pF VS = ±15V VO = 10VP-P AV = +1, +10, +100 MEASUREMENT BANDWIDTH = 10Hz TO 80kHz 1677 G28 Total Harmonic Distortion and Noise vs Frequency for Inverting Gain 0.1 0.1 0.0001 –50 100k 1677 G29 0.01 25°C 1 Total Harmonic Distortion and Noise vs Output Amplitude for Inverting Gain ZL = 2k/15pF VS = ±15V fO = 1kHz AV = +1, +10, +100 MEASUREMENT BANDWIDTH = 10Hz TO 22kHz AV = 100 0.1 0.01 AV = 10 AV = 1 0.001 0.0001 0.3 1 10 OUTPUT SWING (VP-P) 30 1677 G32 TOTAL HARMONIC DISTORTION + NOISE (%) OUTPUT IMPEDANCE (Ω) 10 VS = ±15V 40 TOTAL HARMONIC DISTROTION + NOISE (%) 50 100 0.001 Total Harmonic Distortion and Noise vs Frequency for Noninverting Gain Output Short-Circuit Current vs Time Closed-Loop Output Impedance vs Frequency 1 ZL = 2k/15pF VS = ±15V fO = 1kHz AV = –1, –10, –100 MEASUREMENT BANDWIDTH = 10Hz TO 22kHz 0.1 AV = –100 0.01 AV = –10 AV = –1 0.001 0.0001 0.3 1 10 OUTPUT SWING (VP-P) 30 1677 G33 1677fa 11 LT1677 U W U U APPLICATIO S I FOR ATIO General The LT1677 series devices may be inserted directly into OP-07, OP-27, OP-37 and sockets with or without removal of external compensation or nulling components. In addition, the LT1677 may be fitted to 741 sockets with the removal or modification of external nulling components. The adjustment range with a 10kΩ pot is approximately ±2.5mV. If less adjustment range is needed, the sensitivity and resolution of the nulling can be improved by using a smaller pot in conjunction with fixed resistors. The example has an approximate null range of ±200µV (Figure 3). Rail-to-Rail Operation 10k 15V To take full advantage of an input range that can exceed the supply, the LT1677 is designed to eliminate phase reversal. Referring to the photographs shown in Figure 1, the LT1677 is operating in the follower mode (AV = +1) at a single 3V supply. The output of the LT1677 clips cleanly and recovers with no phase reversal. This has the benefit of preventing lock-up in servo systems and minimizing distortion components. 2 – 1 8 7 LT1677 INPUT 3 6 OUTPUT + 4 –15V 1677 F02 Figure 2. Standard Adjustment 1k Offset Voltage Adjustment 15V 4.7k The input offset voltage of the LT1677 and its drift with temperature are permanently trimmed at wafer testing to a low level. However, if further adjustment of VOS is necessary, the use of a 10kΩ nulling potentiometer will not degrade drift with temperature. Trimming to a value other than zero creates a drift of (VOS / 300)µV/°C, e.g., if VOS is adjusted to 300µV, the change in drift will be 1µV/°C (Figure 2). Figure 3. Improved Sensitivity Adjustment Input = – 0.5V to 3.5V LT1677 Output 4.7k 2 3 + 8 LT1677 7 6 OUTPUT 4 –15V 3V 3V 2V 2V 1V 1V 0V 0V – 0.5V – 0.5V 1577 F01a – 1 1677 F03 1577 F01b Figure 1. Voltage Follower with Input Exceeding the Supply Voltage (VS = 3V) 1677fa 12 LT1677 U W U U APPLICATIO S I FOR ATIO Offset Voltage and Drift Thermocouple effects, caused by temperature gradients across dissimilar metals at the contacts to the input terminals, can exceed the inherent drift of the amplifier unless proper care is exercised. Air currents should be minimized, package leads should be short, the two input leads should be close together and maintained at the same temperature. The circuit shown to measure offset voltage is also used as the burn-in configuration for the LT1677, with the supply voltages increased to ±20V (Figure 4). 50k* 15V 2 100Ω* 3 – 7 LT1677 + 4 50k* –15V 6 As with all operational amplifiers when RF > 2k, a pole will be created with RF and the amplifier’s input capacitance, creating additional phase shift and reducing the phase margin. A small capacitor (20pF to 50pF) in parallel with RF will eliminate this problem. Noise Testing The 0.1Hz to 10Hz peak-to-peak noise of the LT1677 is measured in the test circuit shown (Figure 6a). The frequency response of this noise tester (Figure 6b) indicates that the 0.1Hz corner is defined by only one zero. The test time to measure 0.1Hz to 10Hz noise should not exceed ten seconds, as this time limit acts as an additional zero to eliminate noise contributions from the frequency band below 0.1Hz. Measuring the typical 90nV peak-to-peak noise performance of the LT1677 requires special test precautions: VOUT VOUT = 1000VOS 1. The device should be warmed up for at least five minutes. As the op amp warms up, its offset voltage changes typically 3µV due to its chip temperature increasing 10°C to 20°C from the moment the power supplies are turned on. In the ten-second measurement interval these temperature-induced effects can easily exceed tens of nanovolts. *RESISTORS MUST HAVE LOW THERMOELECTRIC POTENTIAL 1677 F04 Figure 4. Test Circuit for Offset Voltage and Offset Voltage Drift with Temperature Unity-Gain Buffer Application When RF ≤ 100Ω and the input is driven with a fast, largesignal pulse (>1V), the output waveform will look as shown in the pulsed operation diagram (Figure 5). During the fast feedthrough-like portion of the output, the input protection diodes effectively short the output to the input and a current, limited only by the output short-circuit protection, will be drawn by the signal generator. With RF ≥ 500Ω, the output is capable of handling the current requirements (IL ≤ 20mA at 10V) and the amplifier stays in its active mode and a smooth transition will occur. RF – 2. For similar reasons, the device must be well shielded from air currents to eliminate the possibility of thermoelectric effects in excess of a few nanovolts, which would invalidate the measurements. 3. Sudden motion in the vicinity of the device can also “feedthrough” to increase the observed noise. Current noise is measured in the circuit shown in Figure 7 and calculated by the following formula: 1/ 2 2⎤ ⎡ 2 ⎢ eno − 130nV • 101 ⎥ ⎦ in = ⎣ 1MΩ 101 ) ( ) ( ( )( ) 2.5V/µs OUTPUT + LT1677 1677 F05 Figure 5. Pulsed Operation The LT1677 achieves its low noise, in part, by operating the input stage at 100µA versus the typical 10µA of most other op amps. Voltage noise is inversely proportional while current noise is directly proportional to the square 1677fa 13 LT1677 U W U U APPLICATIO S I FOR ATIO 100 0.1µF 90 100k – 2k * LT1677 + + 4.3k – 2.2µF VOLTAGE GAIN = 50,000 24.3k 500k + 0.1 1 10 FREQUENCY (Hz) 100 Figure 6b. 0.1Hz to 10Hz Peak-to-Peak Noise Tester Frequency Response root of the input stage current. Therefore, the LT1677’s current noise will be relatively high. At low frequencies, the low 1/f current noise corner frequency (≈ 90Hz) minimizes current noise to some extent. LT1677 eno Figure 7 In most practical applications, however, current noise will not limit system performance. This is illustrated in the Total Noise vs Source Resistance plot (Figure 8) where: Total Noise = [(op amp voltage noise)2 + (resistor noise)2 + (current noise RS)2]1/2 Three regions can be identified as a function of source resistance: 1000 VS = ±15V TA = 25°C R TOTAL NOISE DENSITY (nV/√Hz) 30 0.01 1677 F06b 1677 F07 R (i) RS ≤ 400Ω. Voltage noise dominates (ii) 400Ω ≤ RS ≤ 50k at 1kHz Resistor noise dominates 400Ω ≤ RS ≤ 8k at 10Hz (iii) RS > 50k at 1kHz Current noise dominates RS > 8k at 10Hz SOURCE RESISTANCE = 2R } AT 1kHz AT 10Hz } 10 RESISTOR NOISE ONLY 1 0.1 50 1677 F06a 100k – 60 40 0.1µF Figure 6a. 0.1Hz to 10Hz Noise Test Circuit 500k 70 110k 100k *DEVICE UNDER TEST NOTE: ALL CAPACITOR VALUES ARE FOR NONPOLARIZED CAPACITORS ONLY 100 SCOPE ×1 RIN = 1M LT1001 4.7µF 100Ω 22µF GAIN (dB) 10Ω 80 1 10 SOURCE RESISTANCE (kΩ) 100 1677 F08 Figure 8. Total Noise vs Source Resistance Clearly the LT1677 should not be used in region (iii), where total system noise is at least six times higher than the voltage noise of the op amp, i.e., the low voltage noise specification is completely wasted. In this region the LT1792 or LT1793 is the best choice. 1677fa 14 LT1677 U W U U APPLICATIO S I FOR ATIO Rail-to-Rail Input Rail-to-Rail Output The LT1677 has the lowest voltage noise, offset voltage and highest gain when compared to any rail-to-rail op amp. The input common mode range for the LT1677 can exceed the supplies by at least 100mV. As the common mode voltage approaches the positive rail (+VS – 0.7V), the tail current for the input pair (Q1, Q2) is reduced, which prevents the input pair from saturating (refer to the Simplified Schematic). The voltage drop across the load resistors RC1, RC2 is reduced to less than 200mV, degrading the slew rate, bandwidth, voltage noise, offset voltage and input bias current (the cancellation is shut off). The rail-to-rail output swing is achieved by using transistor collectors (Q28, Q29) instead of customary class A-B emitter followers for the output stage. Referring to the Simplified Schematic, the output NPN transistor (Q29) sinks the current necessary to move the output in the negative direction. The change in Q29’s base emitter voltage is reflected directly to the gain node (collectors of Q20 and Q16). For large sinking currents, the delta VBE of Q29 can dominate the gain. Figure 9 shows the change in input voltage for a change in output voltage for different load resistors connected between the supplies. The gain is much higher for output voltages above ground (Q28 sources current) since the change in base emitter voltage of Q28 is attenuated by the gain in the PNP portion of the output stage. Therefore, for positive output swings (output sourcing current) there is hardly any change in input voltage for any load resistance. Highest gain and best linearity is achieved when the output is sourcing current, which is the case in single supply operation when the load is ground referenced. Figure 10 shows gains for both sinking and sourcing load currents for a worst-case load of 600Ω. RL = 600 RL = 1k RL = 10k – 15 – 10 – 5 0 5 10 15 OUTPUT VOLTAGE (V) TA = 25°C VS = ±15V RL CONNECTED TO 0V MEASURED ON TEKTRONIX 577 CURVE TRACER Figure 9. Voltage Gain Split Supply RL TO 5V INPUT VOLTAGE (5µV/DIV) INPUT VOLTAGE (50µV/DIV) When the input common mode range goes below 1.5V above the negative rail, the NPN input pair (Q1, Q2) shuts off and the PNP input pair (Q8, Q9) turns on. The offset voltage, input bias current, voltage noise and bandwidth are also degraded. The graph of Offset Voltage Shift vs Common Mode shows where the knees occur by displaying the change in offset voltage. The change-over points are temperature dependent, see the graph Common Mode Range vs Temperature. RL TO 0V 0 1 2 3 4 OUTPUT VOLTAGE (V) TA = 25°C VS = 5V RL = 600Ω MEASURED ON TEKTRONIX 577 CURVE TRACER 5 Figure 10. Voltage Gain Single Supply 1677fa 15 LT1677 U TYPICAL APPLICATIO S Microvolt Comparator with Hysteresis 3V Strain Gauge Amplifier 3V 3V 10M 5% 3 + 7 1 INPUT 2 – 15k 1% LT1677 6 R11 1k 15k 1% R9 3.4Ω R8 7.5Ω R* R* R* R* R7 22.1Ω R2 5Ω OUTPUT R10 232Ω 4 R3 5.49k R5 698Ω 3V + 1677 TA03 – POSITIVE FEEDBACK TO ONE OF THE NULLING TERMINALS CREATES APPROXIMATELY 5µV OF HYSTERESIS. OUTPUT CAN SINK 16mA INPUT OFFSET VOLTAGE IS TYPICALLY CHANGED LESS THAN 5µV DUE TO THE FEEDBACK VOUT LT1677 R* R4 5.49k R2 5Ω *OMEGA SG-3/350LY11 350Ω, 1% ALL OTHER RESISTORS 1% ( )( FOR TEMP COMPENSATION R* OF GAIN R6 22.1Ω ) 1677 TA06 R4 ≅ 1000 AV = 2 • R* + R6 R2 + (R*/2) R6 TRIM R11 FOR BRIDGE BALANCE Precision High Side Current Sense SOURCE 3V < VS < 36V RIN 1k RLINE 0.1Ω 2 3 – + 7 LT1677 4 LOAD 6 ZETEX BC856B VOUT ROUT ROUT VOUT 20k ILOAD = RLINE RIN = 2V/AMP 1677 TA07 1677fa 16 LT1677 U TYPICAL APPLICATIO S 3V Super Electret Microphone Amplifier with DC Servo 1.5V 1.5V 2N3906 2N3906 C1 10pF R1 1M 16kHz ROLL OFF 3 – + R3 1M 2 – 3 + 7 LT1677 R5 2k 1.5V 1.5V 2 C3 0.022µF 7Hz POLE FOR SERVO 7 LT1677 6 4 6 –1.5V 4 R2 80k –1.5V C4 1µF PANASONIC ELECTRET CONDENSER MICROPHONE WM-61 (714) 373-7334 R4 8k C2 100pF 20kHz ROLL OFF 1.5V 2 3 – + 7 LT1677 6 TO HEADPHONES 4 –1.5V –1.5V 1677 TA05 1677fa 17 Q13 ×2 IA Q21 R21 100Ω R24 100Ω Q24 Q8 Q9 R9 200Ω Q1A RC1A 6k Q3 Q1B Q12 100µA IC Q2A Q10 PAD 8 Q2B RC2A 6k RC2B 1k Q6 Q4 ID 50µA Q11 Q7 IC = 200µA VCM < 0.7V BELOW +VS ID = 100µA VCM < 0.7V BELOW +VS 50µA VCM > 0.7V BELOW +VS 0µA VCM > 0.7V BELOW +VS R8 200Ω D2 D3 IB D1 D4 IA, IB = 0µA VCM > 1.5V ABOVE –VS 200µA VCM < 1.5V ABOVE –VS R13 100Ω +IN –IN Q5 PAD 1 C10 81pF Q17 Q15 50µA Q18 R15 1k Q19 R19 2k R14 1k Q14 Q22 100µA 200µA R16 1k Q16 160µA Q20 R20 2k + R25 1k Q25 Q23 C2 80pF R2 50Ω Q32 R30 2k Q30 Q31 R32 1.5k R26 100Ω Q26 R1 500Ω Q35 Q38 Q34 R3 100Ω C1 40pF + RC1B 1k C3 40pF Q27 R34 2k R54 100Ω 1677 SS R23B 10k R29 10Ω Q29 Q28 –VS C4 20pF R23A 10k + + 18 + +VS OUT LT1677 W W SI PLIFIED SCHE ATIC 1677fa LT1677 U PACKAGE DESCRIPTIO Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead PDIP (Narrow 0.300) (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) .065 (1.651) TYP .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 8.255 +0.889 –0.381 .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) ) .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 .100 (2.54) BSC (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) S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (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) 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN .053 – .069 (1.346 – 1.752) .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) 2 3 4 .004 – .010 (0.101 – 0.254) .050 (1.270) BSC SO8 0303 1677fa 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 LT1677 U TYPICAL APPLICATIO gain of ~107. Components R5 and Q1 convert the voltage into a current for transmission back to R10, which converts it into a voltage again. The LM334 and 2N3904 are not temperature compensated so the DC output contains temperature information. This 2-wire remote Geophone preamp operates on a current-loop principle and so has good noise immunity. Quiescent current is ≈10mA for a VOUT of 2.5V. Excitation will cause AC currents about this point of ~±4mA for a VOUT of ~±1V max. The op amp is configured for a voltage 2-Wire Remote Geophone Preamp R9 20Ω V+ R LINEAR TECHNOLOGY LM334Z 6mA R8 11Ω V– 3V C LT1431CZ R R6 4.99k + R7 24.9k A R4 14k C3 220µF R1 365Ω GEOSPACE GS-20DX RL = 630Ω GEOPHONE www.geospacecorp.com/default.htm (713) 939-7093 R2 100k 2 – 3 + 7 – LT1677 + C2 0.1µF Q1 2N3904 12V R5 243Ω R10 250Ω 6 VOUT 2.5V ±1V 4 R3 16.2k C4 1000pF 1677 TA04 AV = R2 + R3||R4 R1 + RL ≅ 107 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1028/LT1128 Ultralow Noise Precision Op Amps Lowest Noise 0.85nV/√Hz LT1115 Ultralow Noise, Low distortion Audio Op Amp 0.002% THD, Max Noise 1.2nV/√Hz LT1124/LT1125 Dual/Quad Low Noise, High Speed Precision Op Amps Similar to LT1007 LT1126/LT1127 Dual/Quad Decompensated Low Noise, High Speed Precision Op Amps Similar to LT1037 LT1226 Low Noise, Very High Speed Op Amp 1GHz, 2.6nV/√Hz, Gain of 25 Stable LT1498/LT1499 10MHz, 5V/µs, Dual/Quad Rail-to-Rail Input and Output Op Amps Precision C-LoadTM Stable LT1792 Low Noise, Precision JFET Input Op Amp 4.2nV/√Hz, 10fA/√Hz LT1793 Low Noise, Picoampere Bias Current Op Amp 6nV/√Hz, 1fA/√Hz, IB = 10pA Max LT1806 Low Noise, 325MHz Rail-to-Rail Input and Output Op Amp 3.5nV/√Hz LT1881/LT1882 Dual/Quad Rail-to-Rail Output Picoamp Input Precision Op Amps CLOAD to 1000pF, IB = 200pA Max LT1884/LT1885 Dual/Quad Rail-to-Rail Output Picoamp Input Precision Op Amps 2.2MHz Bandwidth, 1.2V/µs SR C-Load is a trademark of Linear Technology Corporation. 1677fa 20 Linear Technology Corporation LT 0306 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com © LINEAR TECHNOLOGY CORPORATION 2000