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| LT1818/LT1819 400MHz, 2500V/s, 9mA Single/Dual Operational Amplifiers FEATURES s s s s s s s s s s s s s s DESCRIPTIO 400MHz Gain Bandwidth Product 2500V/s 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 8A 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: - 40C to 85C The LT(R)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 100 load to 3.8V with 5V supplies. On a single 5V supply, the output swings from 1V to 4V with a 100 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. 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. , LTC and LT are registered trademarks of Linear Technology Corporation. APPLICATIO S s s s s s s s Wideband Amplifiers Buffers Active Filters Video and RF Amplification Communication Receivers Cable Drivers Data Acquisition Systems TYPICAL APPLICATIO FFT of Single Supply ADC Driver Single Supply Unity-Gain ADC Driver for Oversampling Applications 5V 2.5VDC 1VAC 5V 0 -10 -20 -30 51.1 LT1818 18pF AMPLITUDE (dBc) + - AIN+ 2.5V AIN- LTC1744 14 BITS 50Msps (SET FOR 2VP-P FULL SCALE) -40 -50 -60 -70 -80 -90 2 18189 TA01 -100 -110 0 5M 10M 15M 20M FREQUENCY (Hz) 25M 18189 TA02 U fIN = 5.102539MHz fS = 50Msps VIN = 300mVP-P SFDR = 78dB 8192 POINT FFT NO WINDOWING OR AVERAGING 3 18189f U U 1 LT1818/LT1819 ABSOLUTE (Note 1) AXI U RATI GS Specified Temperature Range (Note 9) ... -40C to 85C Maximum Junction Temperature .......................... 150C Storage Temperature Range ................. - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C 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) .. - 40C to 85C PACKAGE/ORDER I FOR ATIO TOP VIEW OUT 1 1 V- 2 +IN 3 + - 4 -IN 5 V+ ORDER PART NUMBER LT1818CS5 LT1818IS5 S5 PART* MARKING LTF7 ORDER PART NUMBER S5 PACKAGE 5-LEAD PLASTIC SOT-23 TJMAX = 150C, JA = 250C/W (NOTE 10) TOP VIEW NC 1 -IN 2 +IN 3 V- 4 - + 8 7 6 5 NC V+ OUT NC LT1818CS8 LT1818IS8 S8 PART MARKING 1818 1818I S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150C, JA = 150C/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 SYMBOL VOS PARAMETER Input Offset Voltage The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 9) VS = 5V, VCM = 0V, unless otherwise noted. CONDITIONS (Note 4) TA = 0C to 70C TA = -40C to 85C TA = 0C to 70C (Note 7) TA = -40C to 85C (Note 7) TA = 0C to 70C TA = -40C to 85C IB Input Bias Current TA = 0C to 70C TA = -40C to 85C en in Input Noise Voltage Density Input Noise Current Density f = 10kHz f = 10kHz q q q q q q q q VOS/T IOS Input Offset Voltage Drift Input Offset Current 2 U U W WW U W TOP VIEW OUT A -IN A +IN A V- 1 2 3 4 8 7 6 5 V+ OUT B -IN B +IN B A B ORDER PART NUMBER LT1819CMS8 LT1819IMS8 MS8 PART MARKING LTE7 LTE5 ORDER PART NUMBER MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150C, JA = 250C/W (NOTE 10) TOP VIEW OUT A 1 -IN A 2 A +IN A 3 V- B 4 5 +IN B 6 -IN B 8 7 V+ OUT B LT1819CS8 LT1819IS8 S8 PART MARKING 1819 1819I S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150C, JA = 150C/W (NOTE 10) MIN TYP 0.2 MAX 1.5 2.0 3.0 15 30 800 1000 1200 8 10 12 UNITS mV mV mV V/C V/C nA nA nA A A A nV/Hz pA/Hz 18189f 10 10 60 -2 6 1.2 LT1818/LT1819 ELECTRICAL CHARACTERISTICS SYMBOL RIN CIN VCM CMRR PARAMETER Input Resistance Input Capacitance Input Voltage Range (Positive/Negative) Common Mode Rejection Ratio The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 9) VS = 5V, VCM = 0V, unless otherwise noted. CONDITIONS VCM = V - + 1.5V to V + - 1.5V Differential Guaranteed by CMRR TA = -40C to 85C VCM = 3.5V TA = 0C to 70C TA = -40C to 85C Guaranteed by PSRR TA = -40C to 85C VS = 2V to 5.5V TA = 0C to 70C TA = -40C to 85C VOUT = 3V, RL = 500 TA = 0C to 70C TA = -40C to 85C VOUT = 3V, RL = 100 TA = 0C to 70C TA = -40C to 85C VOUT = 3V, LT1819 TA = 0C to 70C TA = -40C to 85C RL = 500, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C RL = 100, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C VOUT = 3V, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C VOUT = 0V, 1V Overdrive (Note 3) TA = 0C to 70C TA = -40C to 85C AV = 1 AV = -1 (Note 5) TA = 0C to 70C TA = -40C to 85C 6VP-P (Note 6) f = 4MHz, RL = 500 TA = 0C to 70C TA = -40C to 85C AV = 1, 10% to 90%, 0.1V Step AV = 1, 50% to 50%, 0.1V Step AV = 1, 0.1V, RL = 100 AV = -1, 0.1%, 5V HD2, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500 HD3, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500 AV = 2, RL = 150 AV = 2, RL = 150 Per Amplifier TA = 0C to 70C TA = -40C to 85C MIN 1.5 TYP 5 750 1.5 4.2 85 1.25 q q q q q q q q q q q q q q q q q MAX q q q 3.5 3.5 75 73 72 Minimum Supply Voltage PSRR Power Supply Rejection Ratio 2 2 AVOL Large-Signal Voltage Gain Channel Separation VOUT Output Swing(Positive/Negative) IOUT Output Current ISC Output Short-Circuit Current 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 97 2.5 6 100 4.1 3.8 70 200 SR Slew Rate 2500 1800 q q FPBW GBW Full Power Bandwidth Gain Bandwidth Product 95 400 q q tr, tf tPD OS tS HD dG dP IS Rise Time, Fall Time Propagation Delay Overshoot Settling Time Harmonic Distortion Differential Gain Differential Phase Supply Current 0.6 1.0 20 10 -85 -89 0.07 0.02 9 q q 10 13 14 UNITS M k 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/s V/s V/s V/s MHz MHz MHz MHz ns ns % ns dBc dBc % DEG mA mA mA 18189f 3 LT1818/LT1819 ELECTRICAL CHARACTERISTICS SYMBOL VOS PARAMETER Input Offset Voltage The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C (Note 9). VS = 5V, 0V; VCM = 2.5V, RL to 2.5V unless otherwise noted. CONDITIONS (Note 4) TA = 0C to 70C TA = -40C to 85C (Note 7) TA = 0C to 70C TA = -40C to 85C TA = 0C to 70C TA = -40C to 85C IB Input Bias Current TA = 0C to 70C TA = -40C to 85C en in RIN CIN VCM Input Noise Voltage Density Input Noise Current Density Input Resistance Input Capacitance Input Voltage Range (Positive) Input Voltage Range (Negative) CMRR Common Mode Rejection Ratio Guaranteed by CMRR TA = -40C to 85C Guaranteed by CMRR TA = -40C to 85C VCM = 1.5V to 3.5V TA = 0C to 70C TA = -40C to 85C Guaranteed by PSRR TA = -40C to 85C VS = 4V to 11V TA = 0C to 70C TA = -40C to 85C VOUT = 1.5V to 3.5V, RL = 500 TA = 0C to 70C TA = -40C to 85C VOUT = 1.5V to 3.5V, RL = 100 TA = 0C to 70C TA = -40C to 85C Channel Separation VOUT = 1.5V to 3.5V, LT1819 TA = 0C to 70C TA = -40C to 85C RL = 500, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C RL = 100, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C Output Swing(Negative) RL = 500, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C RL = 100, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C q q q q q q q q q q q q q q q q q q q q q q q q q q q MIN TYP 0.4 MAX 2.0 2.5 3.5 15 30 800 1000 1200 8 10 12 UNITS mV mV mV V/C V/C nA nA nA A A A nV/Hz pA/Hz M k pF V V VOS/T Input Offset Voltage Drift 10 10 60 IOS Input Offset Current -2.4 f = 10kHz f = 10kHz VCM Differential = V- + 1.5V to V + - 1.5V 1.5 6 1.4 5 750 1.5 3.5 3.5 4.2 0.8 73 71 70 82 1.5 1.5 V V dB dB dB Minimum Supply Voltage PSRR Power Supply Rejection Ratio 1.25 78 76 75 1.0 0.7 0.6 0.7 0.5 0.4 81 80 79 3.9 3.8 3.7 3.7 3.6 3.5 97 2 2 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 AVOL Large-Signal Voltage Gain 2 4 100 VOUT Output Swing(Positive) 4.2 4 0.8 1.1 1.2 1.3 1.3 1.4 1.5 V V V V V V 18189f 1 q q 4 LT1818/LT1819 ELECTRICAL CHARACTERISTICS SYMBOL IOUT PARAMETER Output Current The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C (Note 9). VS = 5V, 0V; VCM = 2.5V, RL to 2.5V unless otherwise noted. CONDITIONS VOUT = 1.5V or 3.5V, 30mV Overdrive TA = 0C to 70C TA = -40C to 85C VOUT = 2.5V, 1V Overdrive (Note 3) TA = 0C to 70C TA = -40C to 85C AV = 1 AV = -1 (Note 5) TA = 0C to 70C TA = -40C to 85C FPBW GBW Full Power Bandwidth Gain Bandwidth Product 2VP-P (Note 6) f = 4MHz, RL = 500 TA = 0C to 70C TA = -40C to 85C AV = 1, 10% to 90%, 0.1V Step AV = 1, 50% to 50%, 0.1V Step AV = 1, 0.1V, RL = 100 HD2, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500 HD3, AV = 2, f = 5MHz, VOUT = 2VP-P, RL = 500 AV = 2, RL = 150 AV = 2, RL = 150 Per Amplifier TA = 0C to 70C TA = -40C to 85C q q q q q q q q q q MIN 30 25 20 80 70 50 450 375 300 240 230 220 TYP 50 MAX UNITS mA mA mA mA mA mA V/s V/s V/s V/s MHz MHz MHz MHz ns ns % dBc dBc % DEG ISC Output Short-Circuit Current 140 SR Slew Rate 1000 800 125 360 tr, tf tPD OS HD dG dP IS Rise Time, Fall Time Propagation Delay Overshoot Harmonic Distortion Differential Gain Differential Phase Supply Current 0.7 1.1 20 -72 -74 0.07 0.07 8.5 10 13 14 mA mA mA 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. Note 6: Full power bandwidth is calculated from the slew rate: FPBW = SR/2VP 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 - 40C to 85C. Note 9: The LT1818C/LT1819C are guaranteed to meet specified performance from 0C to 70C and is designed, characterized and expected to meet the extended temperature limits, but is not tested at -40C and 85C. The LT1818I/LT1819I are guaranteed to meet the extended temperature limits. Note 10: Thermal resistance (JA) 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 TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Temperature 12 PER AMPLIFIER 10 VS = 5V VS = 2.5V 6 4 2 0 -50 -25 V+ - 0.5 INPUT COMMON MODE RANGE (V) 8 -1.5 - 2.0 INPUT BIAS CURRENT (A) SUPPLY CURRENT (mA) 50 25 0 75 TEMPERATURE (C) Input Bias Current vs Temperature 0 -0.4 VCM = 0V INPUT VOLTAGE NOISE (nV/Hz) INPUT BIAS CURRENT (A) -0.8 -1.2 -1.6 -2.0 -2.4 -2.8 -50 -25 VS = 5V VS = 2.5V OPEN-LOOP GAIN (dB) 50 25 75 0 TEMPERATURE (C) Open-Loop Gain vs Temperature 80 77 OPEN-LOOP GAIN (dB) VS = 5V VO = 3V OUTPUT VOLTAGE SWING (V) -1.0 -1.5 - 2.0 RL = 100 74 71 68 65 62 -50 -25 RL = 500 OUTPUT VOLTAGE SWING (V) RL = 100 50 25 75 0 TEMPERATURE (C) 6 UW 100 125 18189 G01 Input Common Mode Range vs Supply Voltage TA = 25C VOS < 1mV 2 Input Bias Current vs Common Mode Voltage TA = 25C VS = 5V -1.0 0 -2 2.0 1.5 1.0 0.5 V- 0 1 4 3 2 5 SUPPLY VOLTAGE ( V) 6 7 -4 -6 -8 -5 0 2.5 - 2.5 INPUT COMMON MODE VOLTAGE (V) 5 18189 G02 18189 G03 Input Noise Spectral Density 100 TA = 25C VS = 5V AV = 101 RS = 10k in 10 en 1 10 INPUT CURRENT NOISE (pA/Hz) Open-Loop Gain vs Resistive Load 80 77 74 71 68 65 VS = 2.5V 62 100 TA = 25C VS = 5V 1 100 125 10 100 1k 10k FREQUENCY (Hz) 0.1 100k 18189 G05 1k LOAD RESISTANCE () 10k 18189 G06 18189 G04 Output Voltage Swing vs Supply Voltage V+ - 0.5 TA = 25C VOS = 30mV RL = 500 Output Voltage Swing vs Load Current 5 TA = 25C VS = 5V VOS = 30mV SOURCE OUTPUT VOLTAGE SWING (V) 4 -2 SINK 3 2.0 1.5 1.0 0.5 V- RL = 500 0 1 4 3 2 5 SUPPLY VOLTAGE ( V) 6 7 RL = 100 -3 2 -4 100 125 -5 -120 -80 0 40 80 -40 OUTPUT CURRENT (mA) 120 18189 G09 18189 G07 18189 G08 18189f LT1818/LT1819 TYPICAL PERFOR A CE CHARACTERISTICS Output Short-Circuit Current vs Temperature 240 OUTPUT SHORT-CIRCUIT CURRENT (mA) VS = 5V VIN = 1V SOURCE 125 SINK OUTUPT CURRENT (mA) OUTPUT IMPEDANCE () 200 160 120 80 40 0 -50 -25 50 25 75 0 TEMPERATURE (C) Gain and Phase vs Frequency 80 70 60 50 PHASE GAIN (dB) GAIN BANDWIDTH (MHz) 40 30 20 10 TA = 25C -10 AV = -1 RL = 500 -20 100k 10k 0 1M 10M FREQUENCY (Hz) Gain vs Frequency, AV = 1 5 TA = 25C AV = 1 RL = 500 10 VS = 2.5V VS = 5V 5 0 GAIN (dB) GAIN (dB) 0 -5 GAIN (dB) -10 1M 10M 100M FREQUENCY (Hz) UW 100 18189 G10 Output Current vs Temperature 150 Output Impedance vs Frequency 100 SOURCE, VS = 5V SINK, VS = 5V SOURCE, VS = 2.5V 10 AV = 100 AV = 10 100 75 1 SINK, VS = 2.5V 50 25 VOS = 30mV VOUT = 3V FOR VS = 5V VOUT = 1V FOR VS = 2.5V 50 25 75 0 TEMPERATURE (C) 100 125 0.1 AV = 1 125 0 -50 -25 0.01 10k TA = 25C VS = 5V 100k 1M 10M FREQUENCY (Hz) 100M 18189 G12 18189 G11 Gain Bandwidth and Phase Margin vs Temperature 180 160 140 120 400 PHASE (DEG) 440 RL = 500 GBW VS = 5V PHASE MARGIN (DEG) GAIN 100 80 60 40 20 0 100M -20 500M 360 GBW VS = 2.5V PHASE MARGIN VS = 2.5V PHASE MARGIN VS = 5V 50 40 -50 -25 50 0 75 25 TEMPERATURE (C) 100 30 125 18189 G13 18189 G15 Gain vs Frequency, AV = 2 RL = 500 5 Gain vs Frequency, AV = - 1 VS = 2.5V VS = 5V RL = 100 0 500M 18189 G16 TA = 25C -5 A = 2 V VS = 5V RF = RG = 500 CF = 1pF -10 10M 1M FREQUENCY (Hz) -5 TA = 25C AV = -1 RL = RF = RG = 500 100M 300M -10 1M 10M FREQUENCY (Hz) 100M 300M 18189 G17 18189 G18 18189f 7 LT1818/LT1819 TYPICAL PERFOR A CE CHARACTERISTICS Gain Bandwidth and Phase Margin vs Supply Voltage 450 400 100 POWER SUPPLY REJECTION RATIO (dB) 80 PSRR 60 +PSRR COMMON MODE REJECTION RATIO (dB) TA = 25C GBW RL = 500 GAIN BANDWIDTH (MHz) 350 300 GBW RL = 100 PHASE MARGIN RL = 100 PHASE MARGIN RL = 500 2 5 4 3 SUPPLY VOLTAGE (V) 6 18189 G19 Slew Rate vs Input Step 2000 TA =25C AV = -1 V = 5V 1600 RS = R = R = 500 F G L SLEW RATE (V/s) SLEW RATE (V/s) SR + 1200 SR - SLEW RATE (V/s) 800 400 0 2 3 4 5 INPUT STEP (VP-P) 6 18189 G22 Differential Gain and Phase vs Supply Voltage TA = 25C DIFFERENTIAL PHASE (DEG) DIFFERENTIAL GAIN RL = 150 0.12 0.10 0.08 0.06 0.04 0.02 0 2 4 3 5 SUPPLY VOLTAGE (V) 6 18189 G25 DISTORTION (dB) -80 -90 -100 -110 AV = 2 VS = 5V VO = 2VP-P DISTORTION (dB) DIFFERENTIAL PHASE RL = 150 8 UW Power Supply Rejection Ratio vs Frequency TA = 25C AV = 1 VS = 5V 100 Common Mode Rejection Ratio vs Frequency TA = 25C 80 VS = 2.5V 60 VS = 5V PHASE MARGIN (DEG) 45 40 35 30 40 40 20 20 0 1k 10k 1M 100k FREQUENCY (Hz) 10M 100M 18189 G20 0 1k 10k 1M 100k FREQUENCY (Hz) 10M 100M 18189 G21 Slew Rate vs Supply Voltage 2000 TA =25C AV = -1 RF = RG = RL = 500 2400 Slew Rate vs Temperature VIN = 6VP-P 2000 1600 1200 800 400 VS = 5V 1500 1000 VIN = 2VP-P 500 VS = 2.5V 0 0 1 4 3 2 5 SUPPLY VOLTAGE (V) 6 7 0 -50 -25 AV = -1 RF = RG = RL = 500 50 25 75 0 TEMPERATURE (C) 100 125 18189 G23 18189 G24 Distortion vs Frequency, AV = 2 -60 0.10 0.08 Distortion vs Frequency, AV = -1 -60 2ND, RL = 100 -70 -80 -90 -100 -110 AV = -1 VS = 5V VO = 2VP-P 2M 5M FREQUENCY (Hz) 10M 18189 G27 2ND, RL = 100 -70 3RD, RL = 100 2ND, RL = 500 DIFFERENTIAL GAIN (%) 0.06 0.04 0.02 0 2ND, RL = 500 3RD, RL = 500 3RD, RL = 500 3RD, RL = 100 -120 1M 2M 5M FREQUENCY (Hz) 10M 18189 G26 -120 1M 18189f LT1818/LT1819 TYPICAL PERFOR A CE CHARACTERISTICS Distortion vs Frequency, AV = 1 -60 -70 AV = 1 VS = 5V VO = 2VP-P 3RD, RL = 100 110 100 CHANNEL SEPARATION (dB) 2ND, RL = 100 DISTORTION (dB) -80 -90 -100 3RD, RL = 500 -110 2ND, RL = 500 -120 1M 2M 5M FREQUENCY (Hz) 10M 18189 G28 Small-Signal Transient, 20dB Gain 20mV/DIV Large-Signal Transient, AV = 1 1V/DIV VS = 5V UW 10ns/DIV 10ns/DIV Channel Separation vs Frequency 0.1% Settling Time INPUT TRIGGER (1V/DIV) OUTPUT SETTLING RESIDUE (5mV/DIV) 90 80 70 60 50 40 T = 25C 30 VA = 5V S 20 AV = -1 RF = RG = RL = 500 10 100k 1M 10M 10k FREQUENCY (Hz) 100M 1G 5ns/DIV VS = 5V VOUT = 2.5V SETTLING TIME = 9ns AV = -1 RF = RG = 500 CF = 4.1pF 18189 G30 18188 G29 Large-Signal Transient, AV = -1 2V/DIV 18189 G31 VS = 5V 5ns/DIV 18189 G32 Large-Signal Transient, AV = -1 1V/DIV 18189 G33 VS = 5V 10ns/DIV 18189 G34 18189f 9 LT1818/LT1819 APPLICATIO S I FOR ATIO 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. Low ESL/ESR bypass capacitors should be placed directly at the positive and negative supply (0.01F ceramics are recommended). For high drive current applications, additional 1F to 10F tantalums should be added. 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 500 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. 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 + RG CG RF CF IN - 10 U load, a resistor of 10 to 50 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. Input Considerations 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 100 source resistance at each input, the 800nA maximum offset current results in only 80V of extra offset, while without balance the 8A maximum input bias current could result in an 0.8mV offset condition. 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. + - RS CLOAD 18189 F01 W U U Figure 1 18189f LT1818/LT1819 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/s) 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 (150C) 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 * JA) 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: PDMAX = (V + - V -) * (ISMAX) + (V+/2)2/RL or PDMAX = (V + - V -) * (ISMAX) + (V+ - VOMAX) * (VOMAX/RL) U Example: LT1819IS8 at 85C, VS = 5V, RL = 100 PDMAX = (10V) * (14mA) + (2.5V)2/100 = 202.5mW TJMAX = 85C + (2 * 202.5mW) * (150C/W) = 146C 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. 18189f W U U 11 LT1818/LT1819 TYPICAL APPLICATIO 10F VIN 5V AMPLITUDE (dBc) 12 U Single Supply Differential ADC Driver 5V + 1/2 LT1819 18pF 51.1 5V - AIN+ 536 536 18pF AIN- LTC1744 14 BITS 50Msps (SET FOR 2VP-P FULL SCALE) - 1/2 LT1819 51.1 18pF 4.99k + 4.99k 0.1F 18189 TA05 Results Obtained with the Circuit of Figure 2 at 5MHz. FFT Shows 81dB Overall Spurious Free Dynamic Range 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 0 5M 10M 15M 20M FREQUENCY (Hz) 25M 18189 TA06 fIN = 5.023193MHz fS = 50Msps VIN = 750mVP-P 8192 SAMPLES NO WINDOWING NO AVERAGING 18189f LT1818/LT1819 SI PLIFIED SCHE ATIC V+ -IN C V- 18189 SS PACKAGE DESCRIPTIO 5.23 (.206) MIN 0.42 0.04 (.0165 .0015) TYP RECOMMENDED SOLDER PAD LAYOUT DETAIL "A" 0 - 6 TYP 4.90 0.15 (1.93 .006) 3.00 0.102 (.118 .004) NOTE 4 0.254 (.010) GAUGE PLANE 0.18 (.077) SEATING PLANE 0.22 - 0.38 (.009 - .015) TYP 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 U W W (One Amplifier) R1 +IN OUT MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660) 0.889 0.127 (.035 .005) 3.2 - 3.45 (.126 - .136) 0.65 (.0256) BSC 3.00 0.102 (.118 .004) (NOTE 3) 8 7 65 0.52 (.206) REF 0.53 0.015 (.021 .006) DETAIL "A" 1 1.10 (.043) MAX 23 4 0.86 (.034) REF 0.65 (.0256) BSC 13 LT1818/LT1819 PACKAGE DESCRIPTIO 0.62 MAX 0.95 REF 3.85 MAX 2.62 REF RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.20 BSC 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) 14 U S5 Package 5-Lead Plastic SOT-23 (Reference LTC DWG # 05-08-1633) 2.80 - 3.10 (NOTE 4) 1.22 REF 1.4 MIN 2.60 - 3.00 1.50 - 1.75 (NOTE 4) PIN ONE 0.25 - 0.50 TYP 5 PLCS NOTE 3 0.95 BSC 0.90 - 1.30 0.00 - 0.15 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 LT1818/LT1819 PACKAGE DESCRIPTIO .050 BSC 8 N N .245 MIN .160 .005 .228 - .244 (5.791 - 6.197) 1 .030 .005 TYP 2 3 N/2 RECOMMENDED SOLDER PAD LAYOUT .010 - .020 x 45 (0.254 - 0.508) .008 - .010 (0.203 - 0.254) 0- 8 TYP .016 - .050 (0.406 - 1.270) NOTE: 1. DIMENSIONS IN 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) 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. U S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .045 .005 .189 - .197 (4.801 - 5.004) NOTE 3 7 6 5 .150 - .157 (3.810 - 3.988) NOTE 3 N/2 1 2 3 4 .053 - .069 (1.346 - 1.752) .004 - .010 (0.101 - 0.254) .014 - .019 (0.355 - 0.483) TYP .050 (1.270) BSC SO8 0502 18189f 15 LT1818/LT1819 TYPICAL APPLICATIO 20dB Gain Block Frequency Response 25 20 15 GAIN (dB) 10 5 0 -5 VS = 5V TA = 25C 1M 10M FREQUENCY (Hz) 100M 18189 TA04 -10 100k RELATED PARTS PART NUMBER LT1395/LT1396/LT1397 LT1806/LT1807 LT1809/LT1810 LT1812/LT1813/LT1814 LT1815/LT1816/LT1817 LT6203/LT6204 DESCRIPTION Single/Dual/Quad 400MHz Current Feedback Amplifiers Single/Dual 325MHz, 140V/s Rail-to-Rail I/O Op Amps Single/Dual 180MHz, 350V/s Rail-to-Rail I/O Op Amps Single/Dual/Quad 100MHz, 750V/s Op Amps Single/Dual/Quad 220MHz, 1500V/s Op Amps Dual/Quad 100MHz, Rail-to-Rail I/O Op Amps COMMENTS 4.6mA Supply Current Low Noise: 3.5nV/Hz Low Distortion: -90dBc at 5MHz Low Power: 3.6mA Max at 5V Programmable Supply Current 1.9nV/Hz Noise, 3mA Max 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 q FAX: (408) 434-0507 q U 80MHz, 20dB Gain Block + 1/2 LT1819 VIN + 1/2 LT1819 VOUT - 432 200 - 432 200 -3dB BANDWIDTH: 80MHz 18189 TA03 Large-Signal Transient Response 1V/DIV 10ns/DIV 18189 TA07 18189f LT/TP 0103 2K * PRINTED IN USA www.linear.com (c) LINEAR TECHNOLOGY CORPORATION 2002 This datasheet has been download from: www..com Datasheets for electronics components. |
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