LT1055/LT1056 Precision, High Speed, JFET Input Operational Amplifiers U DESCRIPTIO FEATURES The LT(R)1055/LT1056 JFET input operational amplifiers combine precision specifications with high speed performance. Guaranteed Offset Voltage: 150V Max -55C to 125C: 500V Max Guaranteed Drift: 4V/C Max Guaranteed Bias Current 70C: 150pA Max 125C: 2.5nA Max Guaranteed Slew Rate: 12V/s Min Available in 8-Pin PDIP and SO Packages For the first time, 16V/s slew rate and 6.5MHz gain bandwidth product are simultaneously achieved with offset voltage of typically 50V, 1.2V/C drift, bias currents of 40pA at 70C and 500pA at 125C. The 150V maximum offset voltage specification is the best available on any JFET input operational amplifier. U APPLICATIO S The LT1055 and LT1056 are differentiated by their operating currents. The lower power dissipation LT1055 achieves lower bias and offset currents and offset voltage. The additional power dissipation of the LT1056 permits higher slew rate, bandwidth and faster settling time with a slight sacrifice in DC performance. Precision, High Speed Instrumentation Logarithmic Amplifiers D/A Output Amplifiers Photodiode Amplifiers Voltage-to-Frequency Converters Frequency-to-Voltage Converters Fast, Precision Sample-and-Hold The voltage-to-frequency converter shown below is one of the many applications which utilize both the precision and high speed of the LT1055/LT1056. For a JFET input op amp with 23V/s guaranteed slew rate, refer to the LT1022 data sheet. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. U TYPICAL APPLICATIO Distribution of Input Offset Voltage (H Package) 1Hz to 10kHz Voltage-to-Frequency Converter 4.7k 3M 15V 140 0.001 (POLYSTYRENE) 75k 2 0.1F 22k 15V 7 - 6 LT1056 3 + 1.5k OUTPUT 1Hz TO 10kHz 0.005% LINEARITY 4 -15V 33pF 3.3M -15V THE LOW OFFSET VOLTAGE OF LT1056 CONTRIBUTES ONLY 0.1Hz OF ERROR WHILE ITS HIGH SLEW RATE PERMITS 10kHz OPERATION. 50% TO 60V 100 80 60 40 20 0.1F = 1N4148 VS = 15V TA = 25C 634 UNITS TESTED FROM THREE RUNS LM329 2N3906 *1% FILM NUMBER OF UNITS 0V TO 10V INPUT 10kHZ TRIM 5k 120 0 -400 200 -200 400 0 INPUT OFFSET VOLTAGE (V) LT1055/56 TA02 LT1055/56 TA01 10556fc 1 LT1055/LT1056 U W W W ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage ...................................................... 20V Differential Input Voltage ....................................... 40V Input Voltage ......................................................... 20V Output Short-Circuit Duration .......................... Indefinite Operating Temperature Range LT1055AM/LT1055M/LT1056AM/ LT1056M (OBSOLETE) .............. -55C to 125C LT1055AC/LT1055C/LT1056AC/ LT1056C ................................................ 0C to 70C Storage Temperature Range All Devices ...................................... - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C W U U PACKAGE/ORDER INFORMATION ORDER PART NUMBER TOP VIEW BAL 1 8 N/C -IN 2 7 V+ +IN 3 6 OUT V- 4 5 BAL LT1055CN8 LT1056CN8 N8 PACKAGE 8-LEAD PDIP TJMAX = 150C, JA = 130C/ W BAL 1 8 N/C -IN 2 7 V+ +IN 3 6 OUT V- 4 5 BAL S8 PART MARKING 1055 1056 TJMAX = 150C, JA = 150C/ W ORDER PART NUMBER 8 -IN 2 LT1055S8 LT1056S8 S8 PACKAGE 8-LEAD PLASTIC SO TOP VIEW NC BALANCE 1 ORDER PART NUMBER TOP VIEW 7 V+ LT1055ACH LT1055CH LT1055AMH LT1055MH 6 OUT 5 BALANCE 4 V- H PACKAGE 8-LEAD TO-5 METAL CAN +IN 3 TJMAX = 150C, JA = 150C/ W, JC = 45C/ W LT1056ACH LT1056CH LT1056AMH LT1056MH OBSOLETE PACKAGE Consider the N8 Package for 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 TA = 25C. VS = 15V, VCM = 0V unless otherwise noted. LT1055AM/LT1056AM LT1055AC/LT1056AC MIN TYP MAX LT1055M/LT1056M LT1055CH/LT1056CH LT1055CN8/LT1056CN8 MIN TYP MAX SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 2) LT1055 H Package LT1056 H Package LT1055 N8 Package LT1056 N8 Package -- -- -- -- 50 50 -- -- 150 180 -- -- -- -- -- -- 70 70 120 140 400 450 700 800 UNITS V V V V IOS Input Offset Current Fully Warmed Up -- 2 10 -- 2 20 pA 10556fc 2 LT1055/LT1056 ELECTRICAL CHARACTERISTICS TA = 25C. VS = 15V, VCM = 0V unless otherwise noted. LT1055AM/LT1056AM LT1055AC/LT1056AC MIN TYP MAX LT1055M/LT1056M LT1055CH/LT1056CH LT1055CN8/LT1056CN8 MIN TYP MAX SYMBOL PARAMETER CONDITIONS IB Fully Warmed Up VCM = 10V -- -- 10 30 50 130 -- -- 10 30 50 150 pA pA Common Mode VCM = -11V to 8V VCM = 8V to 11V -- -- -- -- 1012 1012 1011 4 -- -- -- -- -- -- -- -- 1012 1012 1011 4 -- -- -- -- pF -- -- 1.8 2.5 -- -- -- -- 2.0 2.8 -- -- VP-P VP-P -- -- 28 14 50 20 -- -- 30 15 60 22 nV/Hz nV/Hz Input Bias Current Input Resistance:Differential Input Capacitance en Input Noise Voltage 0.1Hz to 10Hz LT1055 LT1056 Input Noise Voltage Density f0 = 10Hz (Note 3) f0 = 1kHz (Note 4) UNITS In Input Noise Current Density f0 = 10Hz, 1kHz (Note 5) -- 1.8 4 -- 1.8 4 fA/Hz AVOL Large-Signal Voltage Gain V0 = 10V 150 130 400 300 -- -- 120 100 400 300 -- -- V/mV V/mV 11 12 -- 11 12 -- V CMRR Common Mode Rejection Ratio VCM = 11V 86 100 -- 83 98 -- dB PSRR Power Supply Rejection Ratio VS = 10V to 18V 90 106 -- 88 104 -- dB VOUT Output Voltage Swing RL = 2k SR Slew Rate GBW Gain Bandwidth Product IS Supply Current RL = 2k RL = 1k Input Voltage Range f = 1MHz 12 13.2 -- 12 13.2 -- V LT1055 LT1056 10 12 13 16 -- -- 7.5 9.0 12 14 -- -- V/s V/s LT1055 LT1056 -- -- 5.0 6.5 -- -- -- -- 4.5 5.5 -- -- MHz MHz LT1055 LT1056 -- -- 2.8 5.0 4.0 6.5 -- -- 2.8 5.0 4.0 7.0 mA mA -- 5 -- -- 5 -- mV Offset Voltage Adjustment Range RPOT = 100k The denotes the specifications which apply over the temperature range 0C TA 70C. VS = 15V, VCM = 0V unless otherwise noted. MIN LT1055AC LT1056AC TYP MAX LT1055CH/LT1056CH LT1055CN8/LT1056CN8 MIN TYP MAX SYMBOL PARAMETER CONDITIONS UNITS VOS Input Offset Voltage (Note 2) LT1055 H Package LT1056 H Package LT1055 N8 Package LT1056 N8 Package -- -- -- -- 100 100 -- -- 330 360 -- -- -- -- -- -- 140 140 250 280 750 800 1250 1350 V V V V Average Temperature Coefficient of Input Offset Voltage H Package (Note 6) N8 Package (Note 6) -- -- 1.2 -- 4.0 -- -- -- 1.6 3.0 8.0 12.0 V/C V/C IOS Input Offset Current Warmed Up TA = 70C LT1055 LT1056 -- -- 10 14 50 70 -- -- 16 18 80 100 pA pA IB Input Bias Current Warmed Up TA = 70C LT1055 LT1056 -- -- 30 40 150 80 -- -- 40 50 200 240 pA pA AVOL Large-Signal Voltage Gain VO = 10V, RL = 2k 80 250 -- 60 250 -- V/mV CMRR Common Mode Rejection Ratio VCM = 10.5V 85 100 -- 82 98 -- dB PSRR Power Supply Rejection Ratio VS = 10V to 18V 89 105 -- 87 103 -- dB VOUT Output Voltage Swing RL = 2k 12 13.1 -- 12 13.1 -- V 10556fc 3 LT1055/LT1056 ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range -55C TA 125C. VS = 15V, VCM = 0V, unless otherwise noted. SYMBOL PARAMETER VOS MIN LT1055AM LT1056AM TYP MAX -- -- 180 180 -- CONDITIONS Input Offset Voltage (Note 2) LT1055 LT1056 MIN LT1055M LT1056M TYP MAX UNITS 500 550 -- -- 250 250 1200 1250 V V 1.3 4.0 -- 1.8 8.0 V/C Average Temperature Coefficient of Input Offset Voltage (Note 6) IOS Input Offset Current Warmed Up TA = 125C LT1055 LT1056 -- -- 0.20 0.25 1.2 1.5 -- -- 0.25 0.30 1.8 2.4 nA nA IB Input Bias Current Warmed Up TA = 125C LT1055 LT1056 -- -- 0.4 0.5 2.5 3.0 -- -- 0.5 0.6 4.0 5.0 nA nA AVOL Large-Signal Voltage Gain VO = 10V, RL = 2k 40 120 -- 35 120 -- CMRR Common Mode Rejection Ratio VCM = 10.5V 85 100 -- 82 98 -- dB PSRR Power Supply Rejection Ratio VS = 10V to 17V 88 104 -- 86 102 -- dB VOUT Output Voltage Swing RL = 2k 12 12.9 -- 12 12.9 -- V V/mV TA = 25C. VS = 15V, VCM = 0V unless otherwise noted. SYMBOL PARAMETER VOS Input Offset Voltage (Note 2) IOS Input Offset Current IB Input Bias Current Input Resistance LT1055CS8/LT1056CS8 MIN TYP MAX CONDITIONS Differential Common Mode 1500 V Fully Warmed Up 5 30 pA Fully Warmed Up VCM = 10V 30 30 100 150 pA pA VCM = -11V to 8V VCM = 8V to 11V 0.4 0.4 0.05 T T T 4 pF Input Capacitance en UNITS 500 Input Noise Voltage 0.1Hz to 10Hz Input Noise Voltage Density fO = 10Hz (Note 4) fO = 1kHz (Note 4) LT1055 LT1056 in Input Noise Current Density fO = 10Hz, 1kHz (Note 5) AVOL Large-Signal Voltage Gain VO = 10V RL = 2k RL = 1k Input Voltage Range VP-P VP-P 2.5 3.5 35 15 70 22 nV/Hz nV/Hz 2.5 10 fA/Hz 120 100 400 300 V/mV V/mV 11 12 V CMRR Common Mode Rejection Ratio VCM = 11V 83 98 dB PSRR Power Supply Rejection Ratio VS = 10V to 18V 88 104 dB VOUT Output Voltage Swing RL = 2K 12 13.2 V SR Slew Rate 7.5 9.0 12 14 V/s V/s GBW Gain Bandwidth Product LT1055 LT1056 4.5 5.5 MHz MHz IS Supply Current LT1055 LT1056 2.8 5.0 Offset Voltage Adjustment Range LT1055 LT1056 f = 1MHz RPOT = 100k 5 4.0 7.0 mA mA mV 10556fc 4 LT1055/LT1056 ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range 0C TA 70C. VS = 15V, VCM = 0V, unless otherwise noted. SYMBOL PARAMETER VOS LT1055CS8/LT1056CS8 MIN TYP MAX CONDITIONS UNITS V Input Offset Voltage (Note 2) 800 2200 Average Temperature Coefficient of Input Offset Voltage 4 15 V/C 18 150 pA 60 400 IOS Input Offset Current Warmed Up, TA = 70C IB Input Bias Current Warmed Up, TA = 70C AVOL Large-Signal Voltage Gain VO = 10V, RL = 2k 60 250 V/mV CMRR Common Mode Rejection Ratio VCM = 10.5V 82 98 dB pA PSRR Power Supply Rejection Ratio VS = 10V to 18V 87 103 dB VOUT Output Voltage Swing RL = 2K 12 13.1 V For MIL-STD components, please refer to LTC883 data sheet for test listing and parameters. 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: Offset voltage is measured under two different conditions: (a) approximately 0.5 seconds after application of power; (b) at TA = 25C only, with the chip heated to approximately 38C for the LT1055 and to 45C for the LT1056, to account for chip temperature rise when the device is fully warmed up. Note 3: 10Hz noise voltage density is sample tested on every lot of A grades. Devices 100% tested at 10Hz are available on request. Note 4: This parameter is tested on a sample basis only. Note 5: Current noise is calculated from the formula: in = (2qlB)1/2, where q = 1.6 * 10 -19 coulomb. The noise of source resistors up to 1G swamps the contribution of current noise. Note 6: Offset voltage drift with temperature is practically unchanged when the offset voltage is trimmed to zero with a 100k potentiometer between the balance terminals and the wiper tied to V +. Devices tested to tighter drift specifications are available on request. 10556fc 5 LT1055/LT1056 U W TYPICAL PERFORMANCE CHARACTERISTICS Input Bias Current Over the Common Mode Range BIAS OR OFFSET CURRENTS MAY BE POSITIVE OR NEGATIVE 100 BIAS CURRENT 30 10 OFFSET CURRENT 3 0 25 75 100 50 AMBIENT TEMPERATURE (C) 125 1200 VS = 15V WARMED UP 800 80 TA = 125C TA = 70C 40 TA = 25C 0 A 0 -400 -40 TA = 70C -80 TA = 125C -800 B A = POSITIVE INPUT CURRENT B = NEGATIVE INPUT CURRENT B -120 -15 -5 0 5 10 -10 COMMON MODE INPUT VOLTAGE (V) LT1055/56 G01 BATTERY VOLTAGE (V) 120 50% TO 1.5V/C 100 80 60 40 20 50% YIELD TO 140V 80 60 40 20 -1200 0 -800 -600 -400 -200 0 200 400 600 800 INPUT OFFSET VOLTAGE (V) 15 LT1055/56 G03 Long Term Drift of Representative Units Warm-Up Drift 100 50 VS = 15V TA = 25C CHANGE IN OFFSET VOLTAGE (V) VS = 15V 634 UNITS TESTED FROM THREE RUNS VS = 15V TA = 25C 550 UNITS TESTED FROM 120 TWO RUNS (LT1056) 100 140 LT1055/56 G02 Distribution of Offset Voltage Drift with Temperature (H Package)* 140 400 A 160 NUMBER OF INPUTS 300 120 80 60 LT1056CN8 40 LT1055CN8 LT1056 H PACKAGE 20 LT1055 H PACKAGE 0 0 -10 -8 -6 -4 -2 0 2 4 6 8 10 OFFSET VOLTAGE DRIFT WITH TEMPERATURE (V/C) VS = 15V TA = 25C 40 OFFSET VOLTAGE CHANGE V) VS = 15V VCM = 0V WARMED UP Distribution of Input Offset Voltage (N8 Package) INPUT BIAS CURRENT, TA = 125C (pA) INPUT BIAS AND OFFSET CURRENT (pA) 1000 INPUT BIAS CURRENT, TA = 25C, TA = 70C (pA) Input Bias and Offset Currents vs Temperature 30 20 10 0 -10 -20 -30 -40 -50 1 3 4 2 TIME AFTER POWER ON (MINUTES) 0 5 1 0 3 2 TIME (MONTHS) 4 LT1055/56 G05 *DISTRIBUTION IN THE PLASTIC (N8) PACKAGE IS SIGNIFICANTLY WIDER. 5 LT1055/56 GO6 LT1055/56 G04 LT1056 LT1055 0 2 6 4 TIME (SECONDS) 8 10 LT1055/56 GO7 Voltage Noise vs Frequency 100 7 70 PEAK-TO-PEAK NOISE 5 50 3 30 f0 = 10kHz 2 20 f0 = 1kHz 1 10 20 30 50 60 40 CHIP TEMPERATURE (C) 70 10 80 LT1055/56 G08 1000 RMS NOISE VOLTAGE DENSITY (nV/Hz) 0.1Hz TO 10Hz PEAK-TO-PEAK NOISE (V/P-P) Noise vs Chip Temperature 10 RMS NOISE VOLTAGE DENSITY (nV/Hz) NOISE VOLTAGE (1V/DIVISION) 0.1Hz to 10Hz Noise VS = 15V TA = 25C 300 100 LT1056 1/f CORNER = 28HZ 30 LT1055 1/f CORNER = 20HZ 10 1 3 10 100 30 FREQUENCY (Hz) 300 1000 LT1055/56 G09 10556fc 6 LT1055/LT1056 U W TYPICAL PERFORMANCE CHARACTERISTICS LT1055 Large-Signal Response 20mV/DIV 5V/DIV Small-Signal Response 5V/DIV LT1056 Large-Signal Response AV = 1, CL = 100pF, 0.5s/DIV AV = 1, CL = 100pF, 0.5s/DIV LT1055/56 G10 LT1055/56 G12 AV = 1, CL = 100pF, 0.2s/DIV LT1055/56 G11 Undistorted Output Swing vs Frequency Output Impedence vs Frequency 10 LT1056 GBW SLEW RATE (V/S) 24 18 LT1056 12 LT1055 GBW 20 6 4 LT1056 SLEW 10 2 LT1055 SLEW 6 VS = 15V f0 = 1MHz FOR GBW 0 0 0.1 1 FREQUENCY (MHz) -25 10 LT1055/56 G13 20 GAIN (dB) GAIN (dB) LT1056 LT1056 120 GAIN 140 LT1055 LT1056 20 -10 100 1k 10k 100k 1M 10M 100M FREQUENCY (Hz) LT1055/56 G16 1000 1 VS = 15V VO = 10V 300 RL = 1k 100 30 160 VS = 15V TA = 25C 0 1000 Voltage Gain vs Temperature 0 10 10 100 FREQUENCY (kHz) LT1055/56 G15 10 40 1 1 PHASE SHIFT (DEGREES) 60 LT1056 AV = 1 PHASE LT1055 80 LT1055 RL = 2k 100 -20 1 LT1056 0.1 100 LT1055 AV = 10 LT1055 Gain, Phase Shift vs Frequency VS = 15V TA = 25C 120 LT1056 LT1055/56 G14 Gain vs Frequency 140 AV = 100 LT1055 125 25 75 TEMPERATURE (C) VS = 15V TA = 25C 10 VOLTAGE GAIN (V/mV) LT1055 8 GAIN BANDWIDTH PRODUCT (MHz) VS = 15V TA = 25C 100 OUTPUT IMPEDANCE () 30 30 PEAK-TO-PEAK OUTPUT SWING (V) Slew Rate, Gain Bandwidth vs Temperature 4 2 FREQUENCY (MHz) 6 8 10 LT1055/56 G17 10 -75 25 -25 75 TEMPERATURE (C) 125 LT1055/56 G18 10556fc 7 LT1055/LT1056 U W TYPICAL PERFORMANCE CHARACTERISTICS LT1055 Settling Time 10 0.5mV 5mV 1mV 0 5mV 2mV -5 10mV 1mV 0.5mV VS = 15V TA = 25C 10mV 1 2 0.5mV 5mV 1mV 5mV -5 10mV 3 0.5mV 2mV 1mV 1 0 2 120 100 60 40 20 90 0 125 10 100 1M 1k 10k 100k FREQUENCY (Hz) LT1055/56 G22 25C 4 TA = 125C LT1055 25C 2 TA = - 55C TA = 125C 10 15 5 SUPPLY VOLTAGE (V) 20 LT1055/56 G25 40 20 100 100k 10k 1k FREQUENCY (Hz) 50 TA = -25C TA = -125C VS = 15V -3 TA = -25C -9 -15 0.1 TA = - 55C 40 0 -6 10M LT1055/56 G24 TA = -55C 6 3 1M Short-Circuit Current vs Time 9 -12 0 NEGATIVE SUPPLY 60 10 SHORT-CIRCUIT CURRENT (mA) OUTPUT VOLTAGE SWING (V) SUPPLY CURRENT (mA) 12 TA = - 55C POSITIVE SUPPLY 80 0 10M 15 LT1056 100 Output Swing vs Load Resistance 8 6 TA = 25C 120 LT1055/56 G23 Supply Current vs Supply Voltage 0 LT1055/56 G21 140 80 CMRR (dB) CMRR, PSRR (dB) 110 100 Power Supply Rejection Ratio vs Frequency VS = 15V TA = 25C 100 25 75 TEMPERATURE (C) -12 Common Mode Rejection Ratio vs Frequency VS = 10V TO 17V FOR PSRR VS = 15V, VCM = 10.5V FOR CMRR -25 -11 LT1055/56 G20 Common Mode and Power Supply Rejections vs Temperature CMRR 10 -14 VS = 15V -15 50 -50 0 TEMPERATURE (C) 3 LT1055/56 G19 PSRR 12 11 -13 SETTLING TIME (S) SETTLING TIME (S) 120 13 VS = 15V TA = 25C 0 -10 0 2mV 5 POWER SUPPLY REJECTION RATIO (dB) 10mV 5 15 14 BATTERY VOLTAGE (V) 2mV OUTPUT VOLTAGE SWING FROM 0V (V) OUTPUT VOLTAGE SWING FROM 0V (V) 10 -10 Common Mode Range vs Temperature LT1056 Settling Time TA = -125C TA = -55C TA = 25C 30 TA = 125C 20 10 VS = 15V 0 -10 SINKING -20 TA = 125C -30 TA = 25C -40 TA = - 55C -50 0.3 1 3 LOAD RESISTANCE (k) 10 LT1055/56 G26 0 2 1 3 TIME FROM OUTPUT SHORT TO GROUND (MINUTES) LT1055/56 G27 10556fc 8 LT1055/LT1056 U U W U APPLICATIONS INFORMATION The LT1055/LT1056 may be inserted directly into LF155A/ LT355A, LF156A/LT356A, OP-15 and OP-16 sockets. Offset nulling will be compatible with these devices with the wiper of the potentiometer tied to the positive supply. N/C OFFSET TRIM V+ 7 OUTPUT Offset Nulling 8 1 6 V+ 3 5 - LT1055 LT1056 + 6 V- GUARD LT1055/56 AI2 LT1055/56 AI1 No appreciable change in offset voltage drift with temperature will occur when the device is nulled with a potentiometer, RP, ranging from 10k to 200k. The LT1055/LT1056 can also be used in LF351, LF411, AD547, AD611, OPA-111, and TL081 sockets, provided that the nulling cicuitry is removed. Because of the LT1055/ LT1056's low offset voltage, nulling will not be necessary in most applications. Achieving Picoampere/Microvolt Performance In order to realize the picoampere-microvolt level accuracy of the LT1055/LT1056 proper care must be exercised. For example, leakage currents in circuitry external to the op amp can significantly degrade performance. High quality insulation should be used (e.g. TeflonTM, Kel-F); cleaning of all insulating surfaces to remove fluxes and other residues will probably be required. Surface coating may be necessary to provide a moisture barrier in high humidity environments. Board leakage can be minimized by encircling the input circuitry 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 connnections to the inverting input at pin 2. Guarding both sides of the printed circuit board is required. Bulk leakage reduction depends on the guard ring width. Teflon is a trademark of Dupont. 3 OUT 4 V- 4 7 IN PU TS 2 2 5 OFFSET TRIM 1 RP The LT1055/LT1056 has the lowest offset voltage of any JFET input op amp available today. However, the offset voltage and its drift with time and temperature are still not as good as on the best bipolar amplifiers because the transconductance of FETs is considerably lower than that of bipolar transistors. Conversely, this lower transconductance is the main cause of the significantly faster speed performance of FET input op amps. Offset voltage also changes somewhat with temperature cycling. The AM grades show a typical 20V hysteresis (30V on the M grades) when cycled over the -55C to 125C temperature range. Temperature cycling from 0C to 70C has a negligible (less than 10V) hysteresis effect. The offset voltage and drift performance are also affected by packaging. In the plastic N8 package the molding compound is in direct contact with the chip, exerting pressure on the surface. While NPN input transistors are largely unaffected by this pressure, JFET device matching and drift are degraded. Consequently, for best DC performance, as shown in the typical performance distribution plots, the TO-5 H package is recommended. Noise Performance The current noise of the LT1055/LT1056 is practically immeasurable at 1.8fA/Hz. At 25C it is negligible up to 1G of source resistance, RS (compound to the noise of RS). Even at 125C it is negligible to 100M of RS. 10556fc 9 LT1055/LT1056 U W U U APPLICATIONS INFORMATION The voltage noise spectrum is characterized by a low 1/f corner in the 20Hz to 30Hz range, significantly lower than on other competitive JFET input op amps. Of particular interest is the fact that with any JFET IC amplifier, the frequency location of the 1/f corner is proportional to the square root of the internal gate leakage currents and, therefore, noise doubles every 20C. Furthermore, as illustrated in the noise versus chip temperature curves, the 0.1Hz to 10Hz peak-to-peak noise is a strong function of temperature, while wideband noise (f0 = 1kHz) is practically unaffected by temperature. Consequently, for optimum low frequency noise, chip temperature should be minimized. For example, operating an LT1056 at 5V supplies or with a 20C/W case-toambient heat sink reduces 0.1Hz to 10Hz noise from typically 2.5VP-P (15V, free-air) to 1.5VP-P. Similiarly, the noise of an LT1055 will be 1.8VP-P typically because of its lower power dissipation and chip temperature. capacitance is isolated from the "false summing" node, and (2) it does not require a "flat top" input pulse since the input pulse is merely used to steer current through the diode bridges. For more details, please see Application Note 10. As with most high speed amplifiers, care should be taken with supply decoupling, lead dress and component placement. When the feedback around the op amp is resistive (RF), a pole will be created with RF, the source resistance and capacitance (RS, CS), and the amplifier input capacitance (CIN 4pF). In low closed-loop gain configurations and with RS and RF in the kilohm range, this pole can create excess phase shift and even oscillation. A small capacitor (CF) in parallel with RF eliminates this problem. With RS (CS + CIN) = RFCF, the effect of the feedback pole is completely removed. CF High Speed Operation RF Settling time is measured in the test circuit shown. This test configuration has two features which eliminate problems common to settling time measurments: (1) probe - RS CIN CS OUTPUT + LT1055/56 AI03 Settling Time Test Circuit 15V 0.01 DISC + 15k 10pF (TYPICAL) 10F SOLID TANTALUM 10k - -15V 15k 0.01 DISC + 2k 50 2W 15V + 10F SOLID TANTALUM 2k + PULSE GEN INPUT (5V MIN STEP) 10F SOLID TANTALUM 15k 0.01 DISC LT1055 LT1056 AUT OUTPUT 4.7k + AMPLIFIER UNDER TEST 10k 2N3866 15V HP5082-8210 HEWLETT PACKARD 1/2 U440 50 2N160 3 -15V OUTPUT TO SCOPE 15V 1/2 U440 -15V 100 DC ZERO 15k + 0.01 DISC 15V 10F SOLID TANTALUM = 1N4148 -15V 3 2N3866 2N5160 4.7k -15V LT1055/56 AI04 10556fc 10 LT1055/LT1056 U U W U APPLICATIONS INFORMATION Voltage Follower with Input Exceeding the Negative Common Mode Range Phase Reversal Protection Most industry standard JFET input op amps (e.g., LF155/ LF156, LF351, LF411, OP15/16) exhibit phase reversal at the output when the negitive common mode limit at the input is exceeded (i.e., from -12V to -15V with 15V supplies). This can cause lock-up in servo systems. As shown below, the LT1055/LT1056 does not have this problem due to unique phase reversal protection circuitry (Q1 on simplified schematic). 15V 2 7 - LT1055/56 INPUT 15V SINE WAVE 3 + 4 2k LT1055/56 AI05 Output LT1055/LT1056 10V/DIV 10V/DIV 10V/DIV OUTPUT -15V Output (LF155/LF56, LF441, OP-15/OP-16) Input 6 0.5ms/DIV 0.5ms/DIV 0.5ms/DIV LT1055/56 AI06 LT1055/56 AI07 LT1055/56 AI08 U TYPICAL APPLICATIONS Exponential Voltage-to-Frequency Converter for Music Synthesizers INPUT 0V TO 10V EXPONENT TRIM 2500* 11.3k* 500pF POLYSTYRENE 15V 5 6 3.57k* ZERO TRIM 4 2 2N3906 2N3904 7 - 500k 3 + SAWTOOTH OUTPUT -15V 1.1k 4.7k 500* 6 LT1055 1k* 562* 15V LM329 4.7k 10k* 10k* 2 15V 7 - LM301A 1k* 3 1 2 SCALE FACTOR 1V IN OCTAVE OUT *1% METAL FILM RESISTOR PIN NUMBERED TRANSISTORS = CA3096 ARRAY 3 15V 6 8 + 1 4 0.01F 9 3k 1N148 8 13 14 15 2.2k 7 33 -15V For ten additional applications utilizing the LT1055 and LT1056, please see the LTC1043 data sheet and Application Note 3. TEMPERATURE CONTROL LOOP LT1055/56 TA03 10556fc 11 LT1055/LT1056 U TYPICAL APPLICATIO S 12-Bit Charge Balance A/D Converter 74C00 28k 0.003F 14k 0.01 2 CLK OUTPUT (B) 15V 7 - 10k 6 LT1055 3 + 10k 2N3904 1N4148 249k* D 4 -15V OUTPUT (A) CLK Q 74C74 Q P CL 1N4148 1N4148 15V 0V TO 10V INPUT 33k LM329 10k 15V COUPLE THERMALLY 6 33k 15V 7 - 2 CIRCUIT OUTPUT fOUT (A) RATIO fCLK (B) LT1001 4 + 3 -15V 1N4148 LT1055/56 TA04 Fast "No Trims" 12-Bit Multiplying CMOS DAC Amplifier Fast, 16-Bit Current Comparator RFEEDBACK REFERENCE IN DELAY = 250ns HP5082-2810 IOUT1 TYPICAL 12-BIT CMOS DAC * = 1% FILM RESISTOR 15V - LT1055 IOUT2 OUTPUT 15V 4.7k 50k* 2 15V - 100k* + INPUT LT1055/56 TA05 3 LT1009 2.5V 7 6 LT1056 + 2 4 3 -15V 3k 8 + 7 LT1011 OUTPUT 1 - 4 -15V LT1055/56 TA06 10556fc 12 LT1055/LT1056 U TYPICAL APPLICATIO S Temperature-to-Frequency Converter 560 1k* 1k* 15V 15V 2N2222 10k 2N2907 6.2k* LM329 0.01F POLYSTYRENE TTL OUTPUT 0kHz TO 1kHz = 0C TO 100C 2.7k 2N2222 2k 100C ADJ 500 0C ADJ 510pF 15V 2 6.2k* 3 10k 7 - 6 LT1055 + 820* 4.7k 4 -15V LM134 510 2V 137* *1% FILM RESISTOR LT1055/56 TA07 100kHz Voltage Controlled Oscillator 15V 2 *1% FILM RESISTOR =1N4148 100kHz DISTORTION TRIM 2k 9.09k* 3 22.1k + 2 - -15V 1k 15V 50k 10Hz DISTORTION TRIM -15V 68k FINE DISTORTION TRIMS POLYSTYRENE 500pF 22M 10k 7 6 2N4391 2N4391 5k* + 4 -15V 2.5k* 2 - 2N4391 + -15V GT UP -V +15V SINE OUT 2VRMS 0kHs TO 100kHs -15 10k 22k HP50822810 2 + 1k 8 LT1011 3 - 1k 7 1 4 20pF 10k VR Y1 Y2 10k* 6 4 +V CC W Z1 Z2 15V 15V 7 LT1056 3 X1 X2 U1 U2 AD639 COM 5k FREQUENCY TRIM 68k 15pF -15V LT1056 3 4 4.5k 15V 10k* 6 LT1056 FREQUENCY LINEARITY = 0.1% FREQUENCY STABILITY = 150ppm/C SETTLING TIME = 1.7s DISTORTION = 0.25% AT 100kHz, 0.07% AT 10zHz 0V TO 10V INPUT 7 - 0.01F -15V LM329 4.7k -15V 4.7k 15V LT1055/56 TA08 10556fc 13 LT1055/LT1056 U TYPICAL APPLICATIO S 12-Bit Voltage Output D/A Converter 12-BIT CURRENT OUTPUT D/A CONVERTER (e.g., 6012,565 OR DAC-80) CF 2 0 TO 2 OR 4mA 15V 7 - 6 LT1056 3 + CF = 15pF TO 33pF SETTLING TIME TO 2mV (0.8 LSB) = 1.5s TO 2s OUTPUT 0V TO 10V 4 -15V LT1055/56 TA09 W W SI PLIFIED SCHE ATIC NULL 5 7 V+ 7k Q8 7k Q7 NULL 1 J5 J6 J7 -INPUT 2 300 7.5pF Q9 +INPUT 3 J1 J2 Q15 Q12 20 Q10 Q11 6 OUTPUT J3 J8 Q2 Q1 Q14 Q13 Q5 8k 200 14k 14k 9pF Q3 120A* (160) Q4 J4 120A* (160) 800A* (1000) 400A* (1100) Q16 3k 50 4 V- *CURRENTS AS SHOWN FOR LT1055. (X) = CURRENTS FOR LT1056. LT1055/56 SCHM 10556fc 14 LT1055/LT1056 U PACKAGE DESCRIPTIO H Package 8-Lead TO-5 Metal Can (.200 Inch PCD) (Reference LTC DWG # 05-08-1320) 0.335 - 0.370 (8.509 - 9.398) DIA 0.305 - 0.335 (7.747 - 8.509) 0.040 (1.016) MAX 0.050 (1.270) MAX SEATING PLANE 0.165 - 0.185 (4.191 - 4.699) GAUGE PLANE 0.010 - 0.045* (0.254 - 1.143) REFERENCE PLANE 0.500 - 0.750 (12.700 - 19.050) 0.016 - 0.021** (0.406 - 0.533) 0.027 - 0.045 (0.686 - 1.143) 45TYP PIN 1 0.028 - 0.034 (0.711 - 0.864) 0.200 (5.080) TYP 0.110 - 0.160 (2.794 - 4.064) INSULATING STANDOFF *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND 0.045" BELOW THE REFERENCE PLANE 0.016 - 0.024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 - 0.610) H8(TO-5) 0.200 PCD 1197 OBSOLETE PACKAGE 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) 10556fc 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 LT1055/LT1056 U TYPICAL APPLICATIO 120V Output Precision Op Amp 125V 1F 25mA OUTPUT HEAT SINK OUTPUT TRANSISTORS 330 510 10k 2N5415 1N965 100pF 10k 2N3440 50k 2 10k 3 INPUT - 1M 2N2222 7 1N4148 27 1N4148 27 6 LT1055 + 1k OUTPUT 4 1k 50k 2N2907 1M 2N5415 2N3440 1N965 510 10k 1F 33pF 100k 330 -125V LT1055/56 TA10 U PACKAGE DESCRIPTIO S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .045 .005 .050 BSC 8 .245 MIN .189 - .197 (4.801 - 5.004) NOTE 3 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 x 45 (0.254 - 0.508) .008 - .010 (0.203 - 0.254) 2 .053 - .069 (1.346 - 1.752) 0- 8 TYP .016 - .050 (0.406 - 1.270) NOTE: 1. DIMENSIONS IN .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) 3 4 .004 - .010 (0.101 - 0.254) .050 (1.270) BSC SO8 0303 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1122 Fast Settling JFET Op Amp 340ns Settling Time, GBW = 14MHz, SR = 60V/s LT1792 Low Noise JFET Op Amp en = 6nV/Hz Max at f = 1kHz 10556fc 16 Linear Technology Corporation LT 0406 REV C * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com (c) LINEAR TECHNOLOGY CORPORATION 1994