LT1221 150MHz, 250V/µs, AV ≥ 4 Operational Amplifier U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Gain-Bandwidth: 150MHz Gain of 4 Stable Slew Rate: 250V/µs Input Noise Voltage: 6nV/√Hz C-LoadTM Op Amp Drives Capacitive Loads Maximum Input Offset Voltage: 600µV Maximum Input Bias Current: 300nA Maximum Input Offset Current: 300nA Minimum Output Swing Into 500Ω: ±12V Minimum DC Gain: 50V/mV, RL = 500Ω Settling Time to 0.1%: 65ns, 10V Step Settling Time to 0.01%: 85ns, 10V Step Differential Gain: 0.08%, AV = 4, RL = 150Ω Differential Phase: 0.2°, AV = 4, RL = 150Ω U APPLICATIO S ■ ■ ■ ■ ■ Wideband Amplifiers Buffers Active Filters Video and RF Amplification Cable Drivers 8-, 10-, 12-Bit Data Acquisition Systems The LT1221 is a member of a family of fast, high performance amplifiers that employ Linear Technology Corporation’s advanced complementary bipolar processing. For unity-gain stable applications the LT1220 can be used, and for gains of 10 or greater the LT1222 can be used. , LTC and LT are registered trademarks of Linear Technology Corporation C-Load is a trademark of Linear Technology Corporation U ■ The LT®1221 is a very high speed operational amplifier with superior DC performance. The LT1221 is stable in a noise gain of 4 or greater. It features reduced input offset voltage, lower input bias currents and higher DC gain than devices with comparable bandwidth and slew rate. The circuit is a single gain stage that includes proprietary DC gain enhancement circuitry to obtain precision with high speed. The high gain and fast settling time make the circuit an ideal choice for data acquisition systems. The circuit is also capable of driving capacitive loads which makes it useful in buffer or cable driver applications. TYPICAL APPLICATIO Summing Amplifier Large-Signal Response Summing Amplifier 1k 1k VA VB VC 1k – LT1221 1k VOUT + LT1221 • TA01 VS = ±15V VIN = 10VP-P f = 2MHz LT1221 • TA02 1 LT1221 W W W AXI U Total Supply Voltage (V + to U ABSOLUTE RATI GS (Note 1) V –) ............................. 36V Differential Input Voltage ........................................ ±6V Input Voltage .......................................................... ±VS Output Short-Circuit Duration (Note 2) ........... Indefinite Specified Temperature Range LT1221C (Note 3) ................................... 0°C to 70°C LT1221M (OBSOLETE) ............... – 55°C to 125°C Operating Temperature Range LT1221C ........................................... – 40°C TO 85°C LT1221M (OBSOLETE) ............... – 55°C to 125°C Maximum Junction Temperature (See Below) Plastic Package ............................................... 150°C Ceramic Package (OBSOLETE) .................. 175°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C U W U PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER TOP VIEW NULL 8 NULL 1 7 V+ 6 VOUT –IN 2 +IN 3 5 NC 4 SPECIAL ORDER CONSULT FACTORY V– H PACKAGE 8-LEAD TO-5 METAL CAN TJMAX = 175°C, θJA = 150°C/W ORDER PART NUMBER TOP VIEW NULL 1 8 NULL –IN 2 7 V+ +IN 3 6 VOUT V– 4 5 NC S8 PACKAGE N8 PACKAGE 8-LEAD PLASTIC DIP 8-LEAD PLASTIC SOIC TJMAX = 150°C, θJA = 130°C/W (N) TJMAX = 150°C, θJA = 190°C/W (S) J8 PACKAGE 8-LEAD CERAMIC DIP TJMAX = 175°C, θJA = 100°C/W (J) OBSOLETE PACKAGE LT1221CN8 LT1221CS8 S8 PART MARKING 1221 ORDER PART NUMBER OBSOLETE PACKAGE Consider the N8 or S8 Package for Alternate Source LT1221MJ8 Consider the N8 Package for Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS SYMBOL VOS IOS IB en in RIN PARAMETER Input Offset Voltage Input Offset Current Input Bias Current Input Noise Voltage Input Noise Current Input Resistance CIN Input Capacitance Input Voltage Range (Positive) Input Voltage Range (Negative) Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Output Swing Output Current Slew Rate Full Power Bandwidth Gain-Bandwidth CMRR PSRR AVOL VOUT IOUT SR GBW 2 TA = 25°C, VS = ±15V, TA = 25°C, VCM = 0V, unless otherwise specified. CONDITIONS (Note 4) f = 10kHz f = 10kHz VCM = ±12V Differential MIN 20 12 VCM = ±12V VS = ±5V to ±15V VOUT = ±10V, RL = 500Ω RL = 500Ω VOUT = ±12V (Note 5) 10V Peak (Note 6) f = 1MHz 92 90 50 12 24 200 TYP 200 100 100 6 2 45 80 2 14 – 13 114 110 100 13 26 250 4 150 MAX 600 300 300 – 12 UNITS µV nA nA nV/√Hz pA/√Hz MΩ kΩ pF V V dB dB V/mV ±V mA V/µs MHz MHz LT1221 ELECTRICAL CHARACTERISTICS SYMBOL tr, tf ts PARAMETER Rise Time, Fall Time Overshoot Propagation Delay Settling Time Differential Gain Differential Phase RO IS Output Resistance Supply Current VS = ±15V, TA = 25°C, VCM = 0V, unless otherwise specified. CONDITIONS AV = 4, 10% to 90%, 0.1V AV = 4, 0.1V AV = 4, 50% VIN to 50% VOUT, 0.1V 10V Step, 0.1% 10V Step, 0.01% f = 3.58MHz, RL = 150Ω (Note 7) f = 3.58MHz, RL = 1k (Note 7) f = 3.58MHz, RL = 150Ω (Note 7) f = 3.58MHz, RL = 1k (Note 7) AV = 4, f = 1MHz MIN TYP 3.2 10 5.4 65 85 0.08 0.02 0.20 0.05 0.3 8 MAX 10.5 UNITS ns % ns ns ns % % DEG DEG Ω mA The ● denotes the specifications which apply over the temperature range 0°C ≤ TA ≤ 70°C, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, unless otherwise specified. SYMBOL VOS IOS IB CMRR PSRR AVOL VOUT IOUT SR IS PARAMETER Input Offset Voltage Input VOS Drift Input Offset Current Input Bias Current Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Output Swing Output Current Slew Rate Supply Current CONDITIONS (Note 4) MIN ● ● ● ● VCM = ±12V VS = ±5V to ±15V VOUT = ±10V, RL = 500Ω RL = 500Ω VOUT = ±12V (Note 5) ● ● ● ● ● ● 92 90 40 12 24 180 ● TYP 0.2 15 100 100 114 110 100 13 26 250 8 MAX 1.5 400 400 11 UNITS mV µV/°C nA nA dB dB V/mV ±V mA V/µs mA The ● denotes the specifications which apply over the temperature range – 55°C ≤ TA ≤ 125°C, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, unless otherwise specified. SYMBOL VOS IOS IB CMRR PSRR AVOL VOUT PARAMETER Input Offset Voltage Input VOS Drift Input Offset Current Input Bias Current Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Output Swing IOUT Output Current SR IS Slew Rate Supply Current CONDITIONS (Note 4) MIN ● ● ● ● VCM = ±12V VS = ±5V to ±15V VOUT = ±10V, RL = 500Ω RL = 500Ω RL = 1k VOUT = ±10V VOUT = ±12V (Note 5) Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: A heat sink may be required when the output is shorted indefinitely. Note 3: Commercial parts are designed to operate over – 40°C to 85°C, but are not tested nor guaranteed beyond 0°C to 70°C. Industrial grade parts specified and tested over –40°C to 85°C are available on special request. Consult factory. ● ● ● ● ● ● ● ● ● 92 90 12.5 10 12 20 12 130 TYP 0.2 15 100 100 114 110 100 13 13 26 13 250 8 MAX 2 800 1000 11 UNITS mV µV/°C nA nA dB dB V/mV ±V ±V mA mA V/µs mA Note 4: Input offset voltage is pulse tested and is exclusive of warm-up drift. Note 5: Slew rate is measured between ±10V on an output swing of ±12V. Note 6: FPBW = SR/2πVP. Note 7: Differential Gain and Phase are tested in AV = 4 with five amps in series. Attenuators of 1/4 are used as loads (36.5Ω, 110Ω and 249Ω, 750Ω). 3 LT1221 U W TYPICAL PERFORMANCE CHARACTERISTICS Input Common Mode Range vs Supply Voltage Supply Current vs Supply Voltage and Temperature MAGNITUDE OF OUTPUT VOLATGE (V) TA = 25°C ∆VOS = 0.5mV 10 15 T = 125°C SUPPLY CURRENT (mA) MAGNITUDE OF INPUT VOLTAGE (V) 20 11 20 +VCM 10 –VCM 5 9 T = 25°C 8 7 6 T = –55°C 0 5 10 15 SUPPLY VOLTAGE (±V) 5 10 15 SUPPLY VOLTAGE (±V) 0 20 15 +VSW 10 –VSW 5 20 5 10 15 SUPPLY VOLTAGE (±V) 0 LT1221 • TPC02 LT1221 • TPC01 500 30 TA = 25°C ∆VOS = 30mV 20 ±15V SUPPLIES 15 10 ±5V SUPPLIES 5 Open-Loop Gain vs Resistive Load 110 TA = 25°C VS = ±15V TA = 25°C 100 300 200 OPEN-LOOP GAIN (dB) INPUT BIAS CURRENT (nA) 400 20 LT1221 • TPC03 Input Bias Current vs Input Common Mode Voltage Output Voltage Swing vs Resistive Load 25 TA = 25°C RL = 500Ω ∆VOS = 30mV 0 5 0 OUTPUT VOLTAGE SWING (VP-P) Output Voltage Swing vs Supply Voltage IB+ 100 IB– 0 –100 –200 –300 VS = ±15V 90 VS = ±5V 80 70 – 400 – 500 –15 0 100 1k LOAD RESISTANCE (Ω) 10k 60 –10 –5 10 0 5 INPUT COMMON MODE VOLTAGE (V) Output Short-Circuit Current vs Temperature 1000 INPUT NOISE VOLTAGE (nV/√Hz) OUTPUT SHORT-CIRCUIT CURRENT (mA) 100 40 35 30 25 20 –50 VS = ±15V TA = 25°C AV = 101 RS = 100k 100 10 in 10 1 en 1 –25 0 25 75 50 TEMPERATURE (°C) 100 125 LT1221 • TPC07 10 100 1k 10k FREQUENCY (Hz) 0.1 100k LT1221 • TPC08 100 INPUT NOISE CURRENT (pA/√Hz) 45 4 Power Supply Rejection Ratio vs Frequency Input Noise Spectral Density VS = ±5V 10k LT1221 • TPC06 LT1221 • TPC05 LT1221 • TPC04 50 100 1k LOAD RESISTANCE (Ω) 10 15 POWER SUPPLY REJECTION RATIO (dB) 10 +PSRR 80 VS = ±15V TA = 25°C 60 –PSRR 40 20 10 0 100 1k 10k 100k 1M FREQUENCY (Hz) 10M 100M LT1221 • TPC09 LT1221 U W TYPICAL PERFORMANCE CHARACTERISTICS Common Mode Rejection Ratio vs Frequency Output Swing and Error vs Settling Time (Noninverting) 10 VS = ±15V TA = 25°C 6 60 40 6 10mV 4 2 0 –2 –4 10mV –6 20 0 1k 10k 1M 100k FREQUENCY (Hz) 10M 1mV OUTPUT SWING (V) 80 1mV 75 100 50 SETTLING TIME (ns) 100 VS = ±15V 40 20 20 0 0 VOLTAGE MAGNITUDE (dB) 20 10k 1M 100k FREQUENCY (Hz) 10M –20 100M VS = ±15V TA = 25°C AV = 4 C = 100pF 18 16 C = 50pF 14 12 10 1 0.01 0.001 10k 100 10 FREQUENCY (MHz) 170 SLEW RATE (V/µs) 300 150 140 130 VS = ±15V AV = – 5 (SR+) + (SR –) SR = 2 275 250 225 200 125 LT1221 • TPC16 1M 10M FREQUENCY (Hz) 175 – 50 –25 0 25 50 75 TEMPERATURE (°C) 100M Total Harmonic Distortion vs Frequency 325 VS = ±15V 160 100k LT1221 • TPC15 Slew Rate vs Temperature 180 100 0.1 LT1221 • TPC14 Gain-Bandwidth vs Temperature 25 50 0 75 TEMPERATURE (°C) 1 C = 1000pF 4 LT1221 • TPC13 120 – 50 – 25 C=0 C = 500pF 8 6 TA = 25°C 125 10 TOTAL HARMONIC DISTORTION AND NOISE (%) VOLTAGE GAIN (dB) 60 VS = ±5V 75 100 50 SETTLING TIME (ns) Closed-Loop Output Impedance vs Frequency VS = ±15V TA = 25°C AV = – 5 22 PHASE MARGIN (DEG) VS = ±5V 25 0 1mV LT1221 • TPC12 24 80 80 10mV LT1220 • TPC11 VS = ±15V 1k 125 Frequency Response vs Capacitive Load 100 –20 100 –4 –8 Voltage Gain and Phase vs Frequency 40 –2 –6 LT1221 • TPC10 60 0 –10 25 1mV 2 –8 0 10mV 4 –10 100M VS = ±15V TA = 25°C 8 OUTPUT IMPEDANCE (Ω) 100 10 VS = ±15V TA = 25°C 8 OUTPUT SWING (V) COMMON MODE REJECTION RATIO (dB) 120 GAIN-BANDWIDTH (MHz) Output Swing and Error vs Settling Time (Inverting) 100 125 LT1221 • TPC19 0.01 VS = ±15V VO = 3VRMS RL = 500Ω AV = 4 AV = –4 0.001 0.0001 10 100 1k 10k FREQUENCY (Hz) 100k LT1220 • TPC18 5 LT1221 U W TYPICAL PERFORMANCE CHARACTERISTICS VS = ±15V VIN = 5VP-P LT1221 • TPC19 f = 5MHz f = 5MHz VS = ±15V VIN = 5VP-P LT1221 • TPC22 f = 2MHz VS = ±15V VIN = 5VP-P f = 20kHz LT1221 • TPC21 Small Signal, AV = – 4, CL = 1,000pF Large Signal, AV = – 4 Small Signal, AV = – 4 U W VS = ±15V VIN = 25mV LT1221 • TPC20 f = 2MHz LT1221 • TPC23 VS = ±15V VIN = 42mV f = 500kHz LT1221 • TPC24 U VS = ±15V VIN = 25mV Large Signal, AV = 4, CL = 10,000pF Large Signal, AV = 4 Small Signal, AV = 4 U APPLICATIONS INFORMATION The LT1221 is stable in noise gains of 4 or greater and may be inserted directly into HA2520/2/5, HA2541/2/4, AD817, AD847, EL2020, EL2044 and LM6361 applications, provided that the nulling circuitry is removed and the amplifier configuration has a high enough noise gain. The suggested nulling circuit for the LT1221 is shown in the following figure. Offset Nulling V+ 5k 1 3 + 0.1µF 8 7 LT1221 2 – 6 4 6 The LT1221 amplifier is easy to apply and tolerant of less than ideal layouts. For maximum performance (for example, fast settling time) use a ground plane, short lead lengths and RF-quality bypass capacitors (0.01µF to 0.1µF). For high drive current applications use low ESR bypass capacitors (1µF to 10µF tantalum). Sockets should be avoided when maximum frequency performance is required, although low profile sockets can provide reasonable performance up to 50MHz. For more details see Design Note 50. Feedback resistors greater than 5k are not recommended because a pole is formed with the input capacitance which can cause peaking or oscillations. Input Considerations 0.1µF V– Layout and Passive Components LT1221 • AI01 Bias current cancellation circuitry is employed on the inputs of the LT1221 so the input bias current and input LT1221 U U W U APPLICATIONS INFORMATION offset current have identical specifications. For this reason, matching the impedance on the inputs to reduce bias current errors is not necessary. Capacitive Loading The LT1221 is stable with capacitive loads. This is accomplished by sensing the load induced output pole and adding compensation at the amplifier gain node. As the capacitive load increases, both the bandwidth and phase margin decrease. There will be peaking in the frequency domain as shown in the curve of Frequency Response vs Capacitive Load. The small-signal transient response will have more overshoot as shown in the photo of the small-signal response with 1000pF load. The large-signal response with a 10,000pF load shows the output slew rate being limited to 4V/µs by the short-circuit current. The LT1221 can drive coaxial cable directly, but for best pulse fidelity a resistor of value equal to the characteristic impedance of the cable (i.e., 75Ω) should be placed in series with the output. The other end of the cable should be terminated with the same value resistor to ground. Compensation The LT1221 has a typical gain-bandwidth product of 150MHz which allows it to have wide bandwidth in high gain configurations (i.e., in a gain of 10, it will have a bandwidth of about 15MHz). The amplifier is stable in a noise gain of 4 so the ratio of the signal at the inverting input to the output must be 1/4 or less. Straightforward gain configurations of 4 or –3 are stable, but there are several others that allow the amplifier to be stable for lower signal gains (the noise gain, however, remains 4 or more). One example is the summing amplifier on the first page of this data sheet. Each input signal has a gain of –1 to the output, but it is easily seen that this configuration is equivalent to a gain of –3 as far as the amplifier is concerned. Another circuit is shown below with a DC gain of 1, but an AC gain of 5. The break frequency of the R-C combination across the amplifier inputs should be approximately a factor of 10 less than the gain-bandwidth of the amplifier divided by the high frequency gain (in this case 1/10 of 150MHz/5 or 3MHz). W W SI PLIFIED SCHE ATIC V+ 7 NULL 1 8 BIAS 1 BIAS 2 6 OUT +IN 3 2 –IN V– 4 LT1221 • SS 7 LT1221 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) 45°TYP 0.028 – 0.034 (0.711 – 0.864) PIN 1 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 8 LT1221 U PACKAGE DESCRIPTIO J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) CORNER LEADS OPTION (4 PLCS) 0.023 – 0.045 (0.584 – 1.143) HALF LEAD OPTION 0.045 – 0.068 (1.143 – 1.727) FULL LEAD OPTION 0.005 (0.127) MIN 0.405 (10.287) MAX 8 7 6 5 0.025 (0.635) RAD TYP 0.220 – 0.310 (5.588 – 7.874) 1 2 0.300 BSC (0.762 BSC) 3 4 0.200 (5.080) MAX 0.015 – 0.060 (0.381 – 1.524) 0.008 – 0.018 (0.203 – 0.457) 0° – 15° NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS 0.045 – 0.065 (1.143 – 1.651) 0.014 – 0.026 (0.360 – 0.660) 0.100 (2.54) BSC 0.125 3.175 MIN J8 1298 OBSOLETE PACKAGE 9 LT1221 U PACKAGE DESCRIPTIO N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) 0.400* (10.160) MAX 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.300 – 0.325 (7.620 – 8.255) 0.009 – 0.015 (0.229 – 0.381) ( +0.035 0.325 –0.015 8.255 +0.889 –0.381 ) 0.045 – 0.065 (1.143 – 1.651) 0.130 ± 0.005 (3.302 ± 0.127) 0.065 (1.651) TYP 0.100 (2.54) BSC 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 1098 *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) 10 LT1221 U PACKAGE DESCRIPTIO S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 8 7 6 5 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) SO8 1298 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0°– 8° TYP 0.016 – 0.050 (0.406 – 1.270) 0.014 – 0.019 (0.355 – 0.483) TYP *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 2 3 4 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC 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 LT1221 U TYPICAL APPLICATIO S Lag Compensation 20MHz, AV = 50 Instrumentation Amplifier + VIN + + VIN VOUT – LT1221 – LT1221 500Ω 10k 100pF – 2k 1k AV = 1, f < 3MHz 1k 200pF LT1221 1k 250Ω LT1221 • TA04 + 250Ω VOUT Cable Driver – 1k 10k LT1221 • TA03 – + VIN 75Ω 75Ω CABLE LT1221 LT1221 VOUT – + 75Ω 1.5k 510Ω LT1221 • TA05 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1220 45MHz, 250V/µs Amplifier Unity Gain Stable Version of the LT1221 LT1222 500MHz, 200V/µs Amplifier AV ≥ 10 Version of the LT1221 12 Linear Technology Corporation 1221fb LT/CP 0901 1.5K REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 1992