LT1818/LT1819 400MHz, 2500V/µs, 9mA Single/Dual Operational Amplifiers U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 400MHz Gain Bandwidth Product 2500V/µs Slew Rate –85dBc Distortion at 5MHz 9mA Supply Current Per Amplifier Space Saving SOT-23 and MS8 Packages 6nV/√Hz Input Noise Voltage Unity-Gain Stable 1.5mV Maximum Input Offset Voltage 8µA Maximum Input Bias Current 800nA Maximum Input Offset Current 40mA Minimum Output Current, VOUT = ±3V ±3.5V Minimum Input CMR, VS = ±5V Specified at ±5V, Single 5V Supplies Operating Temperature Range: – 40°C to 85°C The LT®1818/LT1819 are single/dual wide bandwidth, high slew rate, low noise and distortion operational amplifiers with excellent DC performance. The LT1818/LT1819 have been designed for wider bandwidth and slew rate, much lower input offset voltage and lower noise and distortion than devices with comparable supply current. The circuit topology is a voltage feedback amplifier with the excellent slewing characteristics of a current feedback amplifier. The output drives a 100Ω load to ±3.8V with ±5V supplies. On a single 5V supply, the output swings from 1V to 4V with a 100Ω load connected to 2.5V. The amplifier is unitygain stable with a 20pF capacitive load without the need for a series resistor. Harmonic distortion is –85dBc up to 5MHz for a 2VP-P output at a gain of 2. U APPLICATIO S ■ ■ ■ ■ ■ ■ ■ The LT1818/LT1819 are manufactured on Linear Technology’s advanced low voltage complementary bipolar process. The LT1818 (single op amp) is available in SOT-23 and SO-8 packages; the LT1819 (dual op amp) is available in MSOP-8 and SO-8 packages. Wideband Amplifiers Buffers Active Filters Video and RF Amplification Communication Receivers Cable Drivers Data Acquisition Systems , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO FFT of Single Supply ADC Driver Single Supply Unity-Gain ADC Driver for Oversampling Applications 0 fIN = 5.102539MHz fS = 50Msps VIN = 300mVP-P SFDR = 78dB 8192 POINT FFT NO WINDOWING OR AVERAGING –10 5V 5V –30 + 51.1Ω AIN+ LT1818 – –20 18pF 2.5V AIN– LTC1744 14 BITS 50Msps (SET FOR 2VP-P FULL SCALE) AMPLITUDE (dBc) 2.5VDC ±1VAC –40 –50 –60 –70 2 3 –80 18189 TA01 –90 –100 –110 0 5M 10M 15M 20M FREQUENCY (Hz) 25M 18189 TA02 18189f 1 LT1818/LT1819 W W W AXI U U ABSOLUTE RATI GS (Note 1) Total Supply Voltage (V + to V –) ........................... 12.6V Differential Input Voltage (Transient Only, Note 2) ..................................... ±6V Output Short-Circuit Duration (Note 3) ........... Indefinite Operating Temperature Range (Note 8) .. – 40°C to 85°C Specified Temperature Range (Note 9) ... –40°C to 85°C Maximum Junction Temperature .......................... 150°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U U W PACKAGE/ORDER I FOR ATIO TOP VIEW 5 V+ OUT 1 1 V– 2 + +IN 3 – 4 –IN S5 PACKAGE 5-LEAD PLASTIC SOT-23 TJMAX = 150°C, θJA = 250°C/W (NOTE 10) –IN 2 +IN 3 V– – + 4 S5 PART* MARKING LTF7 8 NC 7 V+ 6 5 LT1818CS8 LT1818IS8 1 2 3 4 NC S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/W (NOTE 10) S8 PART MARKING 1818 1818I 8 7 6 5 A B V+ OUT B –IN B +IN B TJMAX = 150°C, θJA = 250°C/W (NOTE 10) MS8 PART MARKING LTE7 LTE5 TOP VIEW ORDER PART NUMBER MS8 PACKAGE 8-LEAD PLASTIC MSOP OUT A 1 –IN A 2 8 V+ 7 OUT B 6 –IN B 5 +IN B LT1819CS8 LT1819IS8 A +IN A 3 OUT ORDER PART NUMBER LT1819CMS8 LT1819IMS8 TOP VIEW OUT A –IN A +IN A V– ORDER PART NUMBER TOP VIEW NC 1 ORDER PART NUMBER LT1818CS5 LT1818IS5 V– B 4 S8 PART MARKING 1819 1819I S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/W (NOTE 10) *The temperature grade is identified by a label on the shipping container. 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. (Note 9) VS = ±5V, VCM = 0V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 4) TA = 0°C to 70°C TA = –40°C to 85°C ● ● TA = 0°C to 70°C (Note 7) TA = –40°C to 85°C (Note 7) ● ● TA = 0°C to 70°C TA = –40°C to 85°C ● ● TA = 0°C to 70°C TA = –40°C to 85°C ● ● ∆VOS/∆T Input Offset Voltage Drift IOS Input Offset Current IB MIN Input Bias Current TYP MAX UNITS 0.2 1.5 2.0 3.0 mV mV mV 10 10 15 30 µV/°C µV/°C 60 800 1000 1200 nA nA nA –2 ±8 ±10 ±12 µA µA µA en Input Noise Voltage Density f = 10kHz 6 nV/√Hz in Input Noise Current Density f = 10kHz 1.2 pA/√Hz 18189f 2 LT1818/LT1819 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 9) VS = ±5V, VCM = 0V, unless otherwise noted. SYMBOL RIN PARAMETER Input Resistance CIN VCM Input Capacitance Input Voltage Range (Positive/Negative) Common Mode Rejection Ratio CMRR Minimum Supply Voltage PSRR AVOL Power Supply Rejection Ratio Large-Signal Voltage Gain Channel Separation VOUT Output Swing(Positive/Negative) IOUT Output Current ISC Output Short-Circuit Current SR Slew Rate FPBW GBW Full Power Bandwidth Gain Bandwidth Product tr, tf tPD OS tS HD Rise Time, Fall Time Propagation Delay Overshoot Settling Time Harmonic Distortion dG dP IS Differential Gain Differential Phase Supply Current CONDITIONS VCM = V – + 1.5V to V + – 1.5V Differential Guaranteed by CMRR TA = –40°C to 85°C VCM = ±3.5V TA = 0°C to 70°C TA = –40°C to 85°C Guaranteed by PSRR TA = –40°C to 85°C VS = ±2V to ±5.5V TA = 0°C to 70°C TA = –40°C to 85°C VOUT = ±3V, RL = 500Ω TA = 0°C to 70°C TA = –40°C to 85°C VOUT = ±3V, RL = 100Ω TA = 0°C to 70°C TA = –40°C to 85°C VOUT = ±3V, LT1819 TA = 0°C to 70°C TA = –40°C to 85°C RL = 500Ω, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C RL = 100Ω, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C VOUT = ±3V, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C VOUT = 0V, 1V Overdrive (Note 3) TA = 0°C to 70°C TA = –40°C to 85°C AV = 1 AV = –1 (Note 5) TA = 0°C to 70°C TA = –40°C to 85°C 6VP-P (Note 6) f = 4MHz, RL = 500Ω TA = 0°C to 70°C TA = –40°C to 85°C AV = 1, 10% to 90%, 0.1V Step AV = 1, 50% to 50%, 0.1V Step AV = 1, 0.1V, RL = 100Ω AV = –1, 0.1%, 5V HD2, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500Ω HD3, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500Ω AV = 2, RL = 150Ω AV = 2, RL = 150Ω Per Amplifier TA = 0°C to 70°C TA = –40°C to 85°C MIN 1.5 ● ● ● ±3.5 ±3.5 75 73 72 TYP 5 750 1.5 ±4.2 85 ±1.25 ● ● ● 78 76 75 1.5 1.0 0.8 1.0 0.7 0.6 82 81 80 ±3.8 ±3.7 ±3.6 ±3.50 ±3.25 ±3.15 ±40 ±35 ±30 ±100 ±90 ±70 ● ● 900 750 600 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● 270 260 250 ±2 ±2 97 2.5 6 100 ±4.1 ±3.8 ±70 ±200 2500 1800 95 400 0.6 1.0 20 10 –85 –89 0.07 0.02 9 ● ● MAX 10 13 14 UNITS MΩ kΩ pF V V dB dB dB V V dB dB dB V/mV V/mV V/mV V/mV V/mV V/mV dB dB dB V V V V V V mA mA mA mA mA mA V/µs V/µs V/µs V/µs MHz MHz MHz MHz ns ns % ns dBc dBc % DEG mA mA mA 18189f 3 LT1818/LT1819 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C (Note 9). VS = 5V, 0V; VCM = 2.5V, RL to 2.5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 4) TA = 0°C to 70°C TA = –40°C to 85°C ● ● (Note 7) TA = 0°C to 70°C TA = –40°C to 85°C ● ● TA = 0°C to 70°C TA = –40°C to 85°C ● ● TA = 0°C to 70°C TA = –40°C to 85°C ● ● ∆VOS/∆T IOS IB Input Offset Voltage Drift Input Offset Current Input Bias Current en Input Noise Voltage Density f = 10kHz in Input Noise Current Density f = 10kHz RIN Input Resistance CIN Input Capacitance VCM Input Voltage Range (Positive) Input Voltage Range (Negative) CMRR Common Mode Rejection Ratio Minimum Supply Voltage PSRR AVOL Power Supply Rejection Ratio Large-Signal Voltage Gain Channel Separation VOUT MIN Output Swing(Positive) Output Swing(Negative) = V– + 1.5V to V + VCM Differential – 1.5V 1.5 3.5 3.5 TYP MAX UNITS 0.4 2.0 2.5 3.5 mV mV mV 10 10 15 30 µV/°C µV/°C 60 800 1000 1200 nA nA nA –2.4 ±8 ±10 ±12 µA µA µA 6 nV/√Hz 1.4 pA/√Hz 5 750 MΩ kΩ 1.5 pF 4.2 V V Guaranteed by CMRR TA = –40°C to 85°C ● Guaranteed by CMRR TA = –40°C to 85°C ● VCM = 1.5V to 3.5V TA = 0°C to 70°C TA = –40°C to 85°C ● ● Guaranteed by PSRR TA = –40°C to 85°C ● VS = 4V to 11V TA = 0°C to 70°C TA = –40°C to 85°C 78 76 75 97 ● ● dB dB dB VOUT = 1.5V to 3.5V, RL = 500Ω TA = 0°C to 70°C TA = –40°C to 85°C 1.0 0.7 0.6 2 ● ● V/mV V/mV V/mV VOUT = 1.5V to 3.5V, RL = 100Ω TA = 0°C to 70°C TA = –40°C to 85°C 0.7 0.5 0.4 4 ● ● V/mV V/mV V/mV VOUT = 1.5V to 3.5V, LT1819 TA = 0°C to 70°C TA = –40°C to 85°C 81 80 79 100 ● ● dB dB dB RL = 500Ω, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C 3.9 3.8 3.7 4.2 ● ● V V V RL = 100Ω, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C 3.7 3.6 3.5 4 ● ● V V V RL = 500Ω, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C ● ● RL = 100Ω, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C ● ● 0.8 73 71 70 1.5 1.5 82 ±1.25 V V dB dB dB ±2 ±2 V V 0.8 1.1 1.2 1.3 V V V 1 1.3 1.4 1.5 V V V 18189f 4 LT1818/LT1819 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C (Note 9). VS = 5V, 0V; VCM = 2.5V, RL to 2.5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP IOUT Output Current VOUT = 1.5V or 3.5V, 30mV Overdrive TA = 0°C to 70°C TA = –40°C to 85°C ±50 ● ● ±30 ±25 ±20 mA mA mA VOUT = 2.5V, 1V Overdrive (Note 3) TA = 0°C to 70°C TA = –40°C to 85°C ±80 ±70 ±50 ±140 ● ● mA mA mA ● ● 450 375 300 ISC SR Output Short-Circuit Current Slew Rate AV = 1 AV = –1 (Note 5) TA = 0°C to 70°C TA = –40°C to 85°C FPBW Full Power Bandwidth 2VP-P (Note 6) GBW Gain Bandwidth Product f = 4MHz, RL = 500Ω TA = 0°C to 70°C TA = –40°C to 85°C ● ● 240 230 220 MAX UNITS 1000 V/µs 800 V/µs V/µs V/µs 125 MHz 360 MHz MHz MHz tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V Step 0.7 ns tPD Propagation Delay AV = 1, 50% to 50%, 0.1V Step 1.1 ns OS Overshoot AV = 1, 0.1V, RL = 100Ω 20 % HD Harmonic Distortion HD2, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500Ω HD3, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500Ω –72 –74 dBc dBc dG Differential Gain AV = 2, RL = 150Ω 0.07 % dP Differential Phase AV = 2, RL = 150Ω 0.07 DEG IS Supply Current Per Amplifier TA = 0°C to 70°C TA = –40°C to 85°C Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Differential inputs of ±6V are appropriate for transient operation only, such as during slewing. Large sustained differential inputs can cause excessive power dissipation and may damage the part. Note 3: A heat sink may be required to keep the junction temperature below absolute maximum when the output is shorted indefinitely. Note 4: Input offset voltage is pulse tested and is exclusive of warm-up drift. Note 5: With ±5V supplies, slew rate is tested in a closed-loop gain of –1 by measuring the rise time of the output from –2V to 2V with an output step from –3V to 3V. With single 5V supplies, slew rate is tested in a closed-loop gain of –1 by measuring the rise time of the output from 1.5V to 3.5V with an output step from 1V to 4V. Falling edge slew rate is not production tested, but is designed, characterized and expected to be within 10% of the rising edge slew rate. 8.5 ● ● 10 13 14 mA mA mA Note 6: Full power bandwidth is calculated from the slew rate: FPBW = SR/2πVP Note 7: This parameter is not 100% tested. Note 8: The LT1818C/LT1818I and LT1819C/LT1819I are guaranteed functional over the operating temperature range of – 40°C to 85°C. Note 9: The LT1818C/LT1819C are guaranteed to meet specified performance from 0°C to 70°C and is designed, characterized and expected to meet the extended temperature limits, but is not tested at –40°C and 85°C. The LT1818I/LT1819I are guaranteed to meet the extended temperature limits. Note 10: Thermal resistance (θJA) varies with the amount of PC board metal connected to the package. The specified values are for short traces connected to the leads. If desired, the thermal resistance can be significantly reduced by connecting the V – pin to a large metal area. 18189f 5 LT1818/LT1819 U W TYPICAL PERFOR A CE CHARACTERISTICS Input Common Mode Range vs Supply Voltage Supply Current vs Temperature V+ 12 PER AMPLIFIER 8 VS = ±2.5V 6 4 2 –1.0 INPUT BIAS CURRENT (µA) INPUT COMMON MODE RANGE (V) SUPPLY CURRENT (mA) VS = ±5V 2 TA = 25°C ∆VOS < 1mV – 0.5 10 Input Bias Current vs Common Mode Voltage –1.5 – 2.0 2.0 1.5 1.0 TA = 25°C VS = ± 5V 0 –2 –4 –6 0.5 50 25 0 75 TEMPERATURE (°C) 100 V– 125 0 4 3 2 5 SUPPLY VOLTAGE (± V) 1 18189 G01 INPUT VOLTAGE NOISE (nV/√Hz) –1.2 –1.6 VS = ±5V –2.0 VS = ±2.5V –2.4 in 10 1 en 1 50 25 75 0 TEMPERATURE (°C) 100 10 125 100 77 74 71 68 VS = ± 5V 65 V+ OUTPUT VOLTAGE SWING (V) RL = 500Ω 65 RL = 100Ω –1.5 – 2.0 2.0 1.5 RL = 100Ω 1.0 100 125 18189 G07 SOURCE –2 –3 4 3 SINK 2 –4 RL = 500Ω V– 50 25 75 0 TEMPERATURE (°C) TA = 25°C VS = ±5V ∆VOS = 30mV RL = 500Ω –1.0 0.5 62 –50 –25 Output Voltage Swing vs Load Current OUTPUT VOLTAGE SWING (V) 71 10k 5 TA = 25°C ∆VOS = 30mV – 0.5 RL = 100Ω 1k LOAD RESISTANCE (Ω) 18189 G06 Output Voltage Swing vs Supply Voltage 74 68 62 100 18189 G05 Open-Loop Gain vs Temperature VS = ± 5V VO = ± 3V 0.1 100k 1k 10k FREQUENCY (Hz) 18189 G04 OPEN-LOOP GAIN (dB) TA = 25°C VS = ± 2.5V –2.8 –50 –25 77 80 OUTPUT VOLTAGE SWING (V) INPUT BIAS CURRENT (µA) TA = 25°C VS = ± 5V AV = 101 RS = 10k INPUT CURRENT NOISE (pA/√Hz) –0.8 80 Open-Loop Gain vs Resistive Load 10 VCM = 0V 5 18189 G03 Input Noise Spectral Density 100 –0.4 0 2.5 – 2.5 INPUT COMMON MODE VOLTAGE (V) 18189 G02 Input Bias Current vs Temperature 0 –8 –5 7 6 OPEN-LOOP GAIN (dB) 0 –50 –25 0 1 4 3 2 5 SUPPLY VOLTAGE (± V) 6 7 18189 G08 –5 –120 –80 0 40 80 –40 OUTPUT CURRENT (mA) 120 18189 G09 18189f 6 LT1818/LT1819 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Short-Circuit Current vs Temperature Output Impedance vs Frequency 100 150 VS = ± 5V VIN = ±1V SOURCE 125 SINK 160 120 80 SOURCE, VS = ±5V 100 SINK, VS = ±5V SINK, VS = ±2.5V 50 100 0 –50 –25 125 50 25 75 0 TEMPERATURE (˚C) 100 180 160 60 140 440 0.01 10k 125 30 80 20 60 10 40 0 20 PHASE (DEG) 100 1M 10M FREQUENCY (Hz) 100M GBW VS = ± 5V GBW VS = ±2.5V 360 PHASE MARGIN VS = ±2.5V 50 PHASE MARGIN VS = ±5V 40 0 1M 10M FREQUENCY (Hz) 100M –20 500M –50 –25 50 0 75 25 TEMPERATURE (°C) 10 VS = ±2.5V VS = ±5V 100 30 125 18189 G15 Gain vs Frequency, AV = 2 Gain vs Frequency, AV = 1 TA = 25°C AV = 1 RL = 500Ω 100k PHASE MARGIN (DEG) 120 GAIN 40 RL = 500Ω 18189 G13 5 TA = 25°C VS = ± 5V 18189 G12 400 GAIN BANDWIDTH (MHz) 80 70 50 GAIN (dB) AV = 1 0.1 Gain Bandwidth and Phase Margin vs Temperature Gain and Phase vs Frequency TA = 25°C –10 AV = –1 RL = 500Ω –20 100k 10k AV = 10 1 18189 G11 18189 G10 PHASE AV = 100 10 ∆VOS = 30mV VOUT = ±3V FOR VS = ±5V VOUT = ±1V FOR VS = ±2.5V 25 50 25 75 0 TEMPERATURE (°C) SOURCE, VS = ±2.5V 75 40 0 –50 –25 OUTPUT IMPEDANCE (Ω) 200 OUTUPT CURRENT (mA) OUTPUT SHORT-CIRCUIT CURRENT (mA) 240 Output Current vs Temperature Gain vs Frequency, AV = – 1 5 RL = 500Ω VS = ±2.5V VS = ±5V 5 RL = 100Ω –5 –10 1M 10M 100M FREQUENCY (Hz) 500M 18189 G16 0 GAIN (dB) GAIN (dB) GAIN (dB) 0 0 TA = 25°C –5 A = 2 V VS = ±5V RF = RG = 500Ω CF = 1pF –10 10M 1M FREQUENCY (Hz) –5 TA = 25°C AV = –1 RL = RF = RG = 500Ω 100M 300M 18189 G17 –10 1M 10M FREQUENCY (Hz) 100M 300M 18189 G18 18189f 7 LT1818/LT1819 U W TYPICAL PERFOR A CE CHARACTERISTICS GBW RL = 500Ω 400 GBW RL = 100Ω 300 PHASE MARGIN RL = 100Ω 45 40 PHASE MARGIN RL = 500Ω PHASE MARGIN (DEG) 350 35 5 4 3 SUPPLY VOLTAGE (±V) TA = 25°C AV = 1 VS = ±5V 80 PSRR +PSRR 60 40 20 TA = 25°C 80 VS = ±2.5V VS = ±5V 60 40 20 0 1k 6 10k 1M 100k FREQUENCY (Hz) 10M 100M 1k 1M 100k FREQUENCY (Hz) 10k 10M 18189 G20 18189 G19 Slew Rate vs Input Step TA =25°C AV = –1 V = ±5V 1600 RS = R = R = 500Ω F G L 100M 18189 G21 Slew Rate vs Supply Voltage 2000 2000 Slew Rate vs Temperature 2400 TA =25°C AV = –1 RF = RG = RL = 500Ω VIN = 6VP-P VS = ±5V 2000 1500 SR + SR – SLEW RATE (V/µs) SLEW RATE (V/µs) 100 0 30 2 Common Mode Rejection Ratio vs Frequency 1200 800 SLEW RATE (V/µs) TA = 25°C POWER SUPPLY REJECTION RATIO (dB) 100 450 GAIN BANDWIDTH (MHz) Power Supply Rejection Ratio vs Frequency COMMON MODE REJECTION RATIO (dB) Gain Bandwidth and Phase Margin vs Supply Voltage 1000 VIN = 2VP-P 1600 1200 VS = ±2.5V 800 500 400 400 0 0 3 4 5 INPUT STEP (VP-P) 0 6 1 4 3 2 5 SUPPLY VOLTAGE (±V) Differential Gain and Phase vs Supply Voltage 0.04 0.10 0.02 0.08 0 0.06 DIFFERENTIAL PHASE RL = 150Ω 4 3 5 SUPPLY VOLTAGE (±V) –80 6 18189 G25 3RD, RL = 500 –100 AV = 2 VS = ±5V VO = 2VP-P –120 1M –80 10M 18189 G26 3RD, RL = 500 –90 3RD, RL = 100 –100 –110 2M 5M FREQUENCY (Hz) 2ND, RL = 500 –70 2ND, RL = 500 –90 –110 0 2 DISTORTION (dB) DIFFERENTIAL PHASE (DEG) 0.12 2ND, RL = 100 3RD, RL = 100 –70 DIFFERENTIAL GAIN (%) 0.06 0.02 –60 2ND, RL = 100 0.08 125 Distortion vs Frequency, AV = –1 –60 0.10 DIFFERENTIAL GAIN RL = 150Ω 100 18189 G24 Distortion vs Frequency, AV = 2 TA = 25°C 50 25 75 0 TEMPERATURE (°C) 18189 G23 18189 G22 0.04 0 –50 –25 7 6 DISTORTION (dB) 2 AV = –1 RF = RG = RL = 500Ω AV = –1 VS = ±5V VO = 2VP-P –120 1M 2M 5M FREQUENCY (Hz) 10M 18189 G27 18189f 8 LT1818/LT1819 U W TYPICAL PERFOR A CE CHARACTERISTICS Channel Separation vs Frequency Distortion vs Frequency, AV = 1 DISTORTION (dB) –70 110 AV = 1 VS = ±5V VO = 2VP-P –80 100 2ND, RL = 100 CHANNEL SEPARATION (dB) –60 3RD, RL = 100 –90 –100 3RD, RL = 500 –110 2ND, RL = 500 –120 1M 0.1% Settling Time 2M 5M FREQUENCY (Hz) 10M INPUT TRIGGER (1V/DIV) 90 80 OUTPUT SETTLING RESIDUE (5mV/DIV) 70 60 50 40 T = 25°C 30 VA = ±5V S 20 AV = –1 RF = RG = RL = 500Ω 10 100k 1M 10M 10k FREQUENCY (Hz) 100M 1G 5ns/DIV VS = ±5V VOUT = ±2.5V SETTLING TIME = 9ns AV = –1 RF = RG = 500Ω CF = 4.1pF 18189 G30 18188 G29 18189 G28 Small-Signal Transient, 20dB Gain 20mV/DIV Large-Signal Transient, AV = –1 2V/DIV 10ns/DIV VS = ±5V 18189 G31 Large-Signal Transient, AV = 1 1V/DIV 5ns/DIV 18189 G32 Large-Signal Transient, AV = –1 1V/DIV VS = ±5V 10ns/DIV 18189 G33 VS = ±5V 10ns/DIV 18189 G34 18189f 9 LT1818/LT1819 U W U U APPLICATIO S I FOR ATIO load, a resistor of 10Ω to 50Ω must be connected between the output and the capacitive load to avoid ringing or oscillation (see RS in Figure 1). The feedback must still be taken directly from the output so that the series resistor will isolate the capacitive load to ensure stability. Layout and Passive Components As with all high speed amplifiers, the LT1818/LT1819 require some attention to board layout. A ground plane is recommended and trace lengths should be minimized, especially on the negative input lead. Input Considerations Low ESL/ESR bypass capacitors should be placed directly at the positive and negative supply (0.01µF ceramics are recommended). For high drive current applications, additional 1µF to 10µF tantalums should be added. The inputs of the LT1818/LT1819 amplifiers are connected to the bases of NPN and PNP bipolar transistors in parallel. The base currents are of opposite polarity and provide first order bias current cancellation. Due to variation in the matching of NPN and PNP beta, the polarity of the input bias current can be positive or negative. The offset current, however, does not depend on beta matching and is tightly controlled. Therefore, the use of balanced source resistance at each input is recommended for applications where DC accuracy must be maximized. For example, with a 100Ω source resistance at each input, the 800nA maximum offset current results in only 80µV of extra offset, while without balance the 8µA maximum input bias current could result in an 0.8mV offset condition. The parallel combination of the feedback resistor and gain setting resistor on the inverting input combine with the input capacitance to form a pole that can cause peaking or even oscillations. If feedback resistors greater than 500Ω are used, a parallel capacitor of value CF > RG • CIN/RF should be used to cancel the input pole and optimize dynamic performance (see Figure 1). For applications where the DC noise gain is 1 and a large feedback resistor is used, CF should be greater than or equal to CIN. An example would be an I-to-V converter. The inputs can withstand differential input voltages of up to 6V without damage and without needing clamping or series resistance for protection. This differential input voltage generates a large internal current (up to 50mA), which results in the high slew rate. In normal transient closed-loop operation, this does not increase power dissipation significantly because of the low duty cycle of the transient inputs. Sustained differential inputs, however, will result in excessive power dissipation and therefore this device should not be used as a comparator. In high closed-loop gain configurations, RF >> RG, and no CF need to be added. To optimize the bandwidth in these applications, a capacitance, CG, may be added in parallel with RG in order to cancel out any parasitic CF capacitance. Capacitive Loading The LT1818/LT1819 are optimized for low distortion and high gain bandwidth applications. The amplifiers can drive a capacitive load of 20pF in a unity-gain configuration and more with higher gain. When driving a larger capacitive IN + IN – + RG RS – CLOAD CG RF CF 18189 F01 Figure 1 18189f 10 LT1818/LT1819 U W U U APPLICATIO S I FOR ATIO Slew Rate The slew rate of the LT1818/LT1819 is proportional to the differential input voltage. Highest slew rates are therefore seen in the lowest gain configurations. For example, a 6V output step with a gain of 10 has a 0.6V input step, whereas at unity gain there is a 6V input step. The LT1818/LT1819 is tested for slew rate at a gain of –1. Lower slew rates occur in higher gain configurations, whereas the highest slew rate (2500V/µs) occurs in a noninverting unity-gain configuration. Power Dissipation The LT1818/LT1819 combine high speed and large output drive in small packages. It is possible to exceed the maximum junction temperature specification (150°C) under certain conditions. Maximum junction temperature (TJ) is calculated from the ambient temperature (TA), power dissipation per amplifier (PD) and number of amplifiers (n) as follows: TJ = TA + (n • PD • θJA) Power dissipation is composed of two parts. The first is due to the quiescent supply current and the second is due to on-chip dissipation caused by the load current. The worst-case load-induced power occurs when the output voltage is at 1/2 of either supply voltage (or the maximum swing if less than 1/2 the supply voltage). Therefore PDMAX is: Example: LT1819IS8 at 85°C, VS = ±5V, RL = 100Ω PDMAX = (10V) • (14mA) + (2.5V)2/100Ω = 202.5mW TJMAX = 85°C + (2 • 202.5mW) • (150°C/W) = 146°C Circuit Operation The LT1818/LT1819 circuit topology is a true voltage feedback amplifier that has the slewing behavior of a current feedback amplifier. The operation of the circuit can be understood by referring to the Simplified Schematic. Complementary NPN and PNP emitter followers buffer the inputs and drive an internal resistor. The input voltage appears across the resistor, generating a current that is mirrored into the high impedance node. Complementary followers form an output stage that buffer the gain node from the load. The input resistor, input stage transconductance and the capacitor on the high impedance node determine the bandwidth. The slew rate is determined by the current available to charge the gain node capacitance. This current is the differential input voltage divided by R1, so the slew rate is proportional to the input step. Highest slew rates are therefore seen in the lowest gain configurations. PDMAX = (V + – V –) • (ISMAX) + (V+/2)2/RL or PDMAX = (V + – V –) • (ISMAX) + (V+ – VOMAX) • (VOMAX/RL) 18189f 11 LT1818/LT1819 U TYPICAL APPLICATIO Single Supply Differential ADC Driver 5V 10µF 18pF + VIN 51.1Ω 1/2 LT1819 5V – AIN+ 18pF 536Ω AIN– 536Ω – LTC1744 14 BITS 50Msps (SET FOR 2VP-P FULL SCALE) 51.1Ω 1/2 LT1819 4.99k 18pF + 5V 4.99k 0.1µF 18189 TA05 Results Obtained with the Circuit of Figure 2 at 5MHz. FFT Shows 81dB Overall Spurious Free Dynamic Range 0 fIN = 5.023193MHz fS = 50Msps VIN = 750mVP-P –10 –20 8192 SAMPLES NO WINDOWING NO AVERAGING AMPLITUDE (dBc) –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 0 5M 10M 15M 20M FREQUENCY (Hz) 25M 18189 TA06 18189f 12 LT1818/LT1819 W W SI PLIFIED SCHE ATIC (One Amplifier) V+ +IN R1 OUT –IN C V– 18189 SS U PACKAGE DESCRIPTIO MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660) 0.889 ± 0.127 (.035 ± .005) 5.23 (.206) MIN 3.2 – 3.45 (.126 – .136) 0.42 ± 0.04 (.0165 ± .0015) TYP 3.00 ± 0.102 (.118 ± .004) (NOTE 3) 0.65 (.0256) BSC 8 7 6 5 0.52 (.206) REF RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) 3.00 ± 0.102 (.118 ± .004) NOTE 4 4.90 ± 0.15 (1.93 ± .006) DETAIL “A” 0° – 6° TYP GAUGE PLANE 0.53 ± 0.015 (.021 ± .006) DETAIL “A” 1 2 3 4 1.10 (.043) MAX 0.86 (.034) REF 0.18 (.077) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 0.65 (.0256) BSC 0.13 ± 0.076 (.005 ± .003) MSOP (MS8) 0802 NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 18189f 13 LT1818/LT1819 U PACKAGE DESCRIPTIO S5 Package 5-Lead Plastic SOT-23 (Reference LTC DWG # 05-08-1633) 0.62 MAX 0.95 REF 2.80 – 3.10 (NOTE 4) 1.22 REF 1.4 MIN 3.85 MAX 2.62 REF 2.60 – 3.00 1.50 – 1.75 (NOTE 4) PIN ONE RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.25 – 0.50 TYP 5 PLCS NOTE 3 0.95 BSC 0.90 – 1.30 0.20 BSC 0.00 – 0.15 0.90 – 1.45 DATUM ‘A’ 0.35 – 0.55 REF 0.09 – 0.20 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ) 1.90 BSC S5 SOT-23 0502 ATTENTION: ORIGINAL SOT23-5L PACKAGE. MOST SOT23-5L PRODUCTS CONVERTED TO THIN SOT23 PACKAGE, DRAWING # 05-08-1635 AFTER APPROXIMATELY APRIL 2001 SHIP DATE 18189f 14 LT1818/LT1819 U PACKAGE DESCRIPTIO S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 .050 BSC 8 7 6 5 N N .245 MIN .160 ±.005 1 .030 ±.005 TYP .150 – .157 (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) 2 3 4 .053 – .069 (1.346 – 1.752) 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 1 .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) .004 – .010 (0.101 – 0.254) .050 (1.270) BSC SO8 0502 18189f 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 LT1818/LT1819 U TYPICAL APPLICATIO 80MHz, 20dB Gain Block + VIN 1/2 LT1819 – + VOUT 1/2 LT1819 432Ω – 432Ω 200Ω 200Ω –3dB BANDWIDTH: 80MHz 18189 TA03 Large-Signal Transient Response 20dB Gain Block Frequency Response 25 20 GAIN (dB) 15 10 1V/DIV 5 0 –5 VS = ±5V TA = 25°C –10 100k 1M 10M FREQUENCY (Hz) 10ns/DIV 100M 18189 TA07 18189 TA04 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1395/LT1396/LT1397 Single/Dual/Quad 400MHz Current Feedback Amplifiers 4.6mA Supply Current LT1806/LT1807 Single/Dual 325MHz, 140V/µs Rail-to-Rail I/O Op Amps Low Noise: 3.5nV/√Hz LT1809/LT1810 Single/Dual 180MHz, 350V/µs Rail-to-Rail I/O Op Amps Low Distortion: –90dBc at 5MHz LT1812/LT1813/LT1814 Single/Dual/Quad 100MHz, 750V/µs Op Amps Low Power: 3.6mA Max at ±5V LT1815/LT1816/LT1817 Single/Dual/Quad 220MHz, 1500V/µs Op Amps Programmable Supply Current LT6203/LT6204 Dual/Quad 100MHz, Rail-to-Rail I/O Op Amps 1.9nV/√Hz Noise, 3mA Max 18189f 16 Linear Technology Corporation LT/TP 0103 2K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www linear.com LINEAR TECHNOLOGY CORPORATION 2002