LT1813 Dual 3mA, 100MHz, 750V/µs Operational Amplifier U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LT®1813 is a low power, high speed, very high slew rate operational amplifier with excellent DC performance. The LT1813 features reduced supply current, lower input offset voltage, lower input bias current and higher DC gain than other devices with comparable bandwidth. The circuit topology is a voltage feedback amplifier with the slewing characteristics of a current feedback amplifier. 100MHz Gain Bandwidth 750V/µs Slew Rate 3.6mA Maximum Supply Current per Amplifier 8nV/√Hz Input Noise Voltage Unity-Gain Stable 1.5mV Maximum Input Offset Voltage 4µA Maximum Input Bias Current 400nA Maximum Input Offset Current 40mA Minimum Output Current, VOUT = ±3V ±3.5V Minimum Input CMR, VS = ±5V Specified at ±5V, Single 5V Available in MS8 and SO-8 Packages The output drives a 100Ω load to ±3.5V with ±5V supplies. On a single 5V supply, the output swings from 1.1V to 3.9V with a 100Ω load connected to 2.5V. The amplifier is stable with a 1000pF capacitive load which makes it useful in buffer and cable driver applications. U APPLICATIO S ■ ■ ■ ■ ■ ■ The LT1813 is manufactured on Linear Technology’s advanced low voltage complementary bipolar process. For higher supply voltage single, dual and quad operational amplifiers with up to 70MHz gain bandwidth, see the LT1351 through LT1365 data sheets. Wideband Amplifiers Buffers Active Filters Video and RF Amplification Cable Drivers Data Acquisition Systems , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO 4MHz, 4th Order Butterworth Filter Filter Frequency Response 10 232Ω 0 274Ω 665Ω VIN – 47pF 274Ω 220pF 562Ω 1/2 LT1813 + 470pF – 22pF 1/2 LT1813 + VOUT 1813 TA01 VOLTAGE GAIN (dB) 232Ω –10 –20 –30 –40 –50 –60 –70 –80 –90 0.1 VS = ±5V VIN = 600mVP-P PEAKING < 0.12dB 1 10 FREQUENCY (MHz) 100 1813 TA02 Powered by ICminer.com Electronic-Library Service CopyRight 2003 1 LT1813 W W U W ABSOLUTE MAXIMUM RATINGS (Note 1) Total Supply Voltage (V + to V –) LT1813 ............................................................. 12.6V LT1813HV ........................................................ 13.5V Differential Input Voltage (Transient Only, Note 2) ... ±3V Input Voltage ........................................................... ±VS Output Short-Circuit Duration (Note 3) ............ Indefinite Operating Temperature Range ................ – 40°C to 85°C Specified Temperature Range (Notes 8, 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 W U U PACKAGE/ORDER INFORMATION ORDER PART NUMBER ORDER PART NUMBER LT1813DMS8* OUT A –IN A +IN A V– 1 2 3 4 8 7 6 5 V+ OUT B –IN B +IN B + OUT A 1 8 V –IN A 2 7 OUT B 6 –IN B 5 +IN B A +IN A 3 V– 4 MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 250°C/ W LT1813CS8 LT1813IS8 LT1813DS8* LT1813HVCS8 LT1813HVIS8 LT1813HVDS8* TOP VIEW TOP VIEW MS8 PART MARKING B S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/ W S8 PART MARKING LTGZ 1813 1813I 1813D 1813HV 813HVI 813HVD Consult factory for Military grade parts. *See note 9. ELECTRICAL CHARACTERISTICS TA = 25°C, VS = ±5V, VCM = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 4) IOS Input Offset Current IB Input Bias Current en Input Noise Voltage f = 10kHz in Input Noise Current f = 10kHz RIN Input Resistance VCM = ±3.5V Differential CIN Input Capacitance Input Voltage Range (High) Input Voltage Range (Low) MIN 3 3.5 TYP MAX UNITS 0.5 1.5 mV 50 400 nA – 0.9 ±4 µA 8 nV/√Hz 1 pA/√Hz 10 1.5 MΩ MΩ 2 pF 4.2 – 4.2 – 3.5 V V CMRR Common Mode Rejection Ratio VCM = ±3.5V 75 85 dB PSRR Power Supply Rejection Ratio VS = ±2V to ±5.5V VS = ±2V to ±6.5V (LT1813HV) 78 75 96 dB dB AVOL Large-Signal Voltage Gain VOUT = ±3V, RL = 500Ω VOUT = ±3V, RL = 100Ω 1.5 1.0 3.0 2.5 V/mV V/mV VOUT Output Swing RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive ±3.80 ±3.35 ±4.0 ±3.5 V V 2 Powered by ICminer.com Electronic-Library Service CopyRight 2003 LT1813 ELECTRICAL CHARACTERISTICS TA = 25°C, VS = ±5V, VCM = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP IOUT Output Current VOUT = ±3V, 30mV Overdrive ±40 ±60 MAX UNITS mA ISC Short-Circuit Current VOUT = 0V, VIN = ±1V ±75 ±100 mA SR Slew Rate AV = – 1 (Note 5) 500 750 V/µs Full Power Bandwidth 3V Peak (Note 6) 40 MHz 100 MHz GBW Gain Bandwidth f = 200kHz tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V, RL = 100Ω RO IS 75 2 ns Overshoot AV = 1, 0.1V, RL = 100Ω 25 % Propagation Delay 50% VIN to 50% VOUT, 0.1V, RL = 100Ω 2.8 ns Output Resistance AV = 1, f = 1MHz Channel Separation VOUT = ±3V, RL = 100Ω Supply Current Per Amplifier VS = ±6.5V (LT1813HV) 82 0.4 Ω 90 dB 3 3.6 4.0 mA mA TYP MAX UNITS 0.7 2 TA = 25°C, VS = 5V, VCM = 2.5V, RL to 2.5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 4) IOS Input Offset Current 50 400 nA IB Input Bias Current –1 ±4 µA en Input Noise Voltage f = 10kHz 8 nV/√Hz in Input Noise Current f = 10kHz 1 pA/√Hz RIN Input Resistance VCM = 1.5V to 3.5V Differential CIN Input Capacitance Input Voltage Range (High) Input Voltage Range (Low) MIN 3 3.5 mV 20 1.5 MΩ MΩ 2 pF 4 1 1.5 V V CMRR Common Mode Rejection Ratio VCM = 1.5V to 3.5V 73 82 dB AVOL Large-Signal Voltage Gain VOUT = 1.5V to 3.5V, RL = 500Ω VOUT = 1.5V to 3.5V, RL = 100Ω 1.0 0.7 2.0 1.5 V/mV V/mV VOUT Output Swing (High) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive 3.9 3.7 4.1 3.9 V V Output Swing (Low) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive Output Current VOUT = 3.5V or 1.5V, 30mV Overdrive ±25 ±35 IOUT 0.9 1.1 1.1 1.3 V V mA ISC Short-Circuit Current VOUT = 2.5V, VIN = ±1V ±55 ±75 mA SR Slew Rate AV = – 1 (Note 5) 200 350 V/µs Full Power Bandwidth 1V Peak (Note 6) 55 MHz GBW Gain Bandwidth f = 200kHz 65 94 MHz tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V, RL = 100Ω 2.1 ns Overshoot AV = 1, 0.1V, RL = 100Ω 25 % Propagation Delay 50% VIN to 50% VOUT, 0.1V, RL = 100Ω 3 ns Output Resistance AV = 1, f = 1MHz Channel Separation VOUT = 1.5V to 3.5V, RL = 100Ω Supply Current Per Amplifier RO IS Powered by ICminer.com Electronic-Library Service CopyRight 2003 81 0.45 Ω 92 dB 2.9 3.6 mA 3 LT1813 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the temperature range 0°C ≤ TA ≤ 70°C. VS = ±5V, VCM = 0V unless otherwise noted (Note 9). SYMBOL VOS CMRR PSRR PARAMETER Input Offset Voltage Input VOS Drift Input Offset Current Input Bias Current Input Voltage Range (High) Input Voltage Range (Low) Common Mode Rejection Ratio Power Supply Rejection Ratio AVOL Large-Signal Voltage Gain VOUT Output Swing IOUT ISC SR GBW Output Current Short-Circuit Current Slew Rate Gain Bandwidth Channel Separation Supply Current IOS IB IS CONDITIONS (Note 4) (Note 7) MIN TYP ● 10 ● ● ● VCM = ±3.5V VS = ±2V to ±5.5V VS = ±2V to ±6.5V (LT1813HV) VOUT = ±3V, RL = 500Ω VOUT = ±3V, RL = 100Ω RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive VOUT = ±3V, 30mV Overdrive VOUT = 0V, VIN = ±1V AV = – 1 (Note 5) f = 200kHz VOUT, ±3V, RL = 100Ω Per Amplifier VS = ±6.5V (LT1813HV) ● ● 3.5 ● 73 76 73 1.0 0.7 ±3.70 ±3.25 ±35 ±60 400 65 81 ● ● ● ● ● ● ● ● ● ● ● MAX 2 15 500 ±5 – 3.5 4.5 5.0 ● ● UNITS mV µV/°C nA µA V V dB dB dB V/mV V/mV V V mA mA V/µs MHz dB mA mA 0°C ≤ TA ≤ 70°C, VS = 5V, VCM = 2.5V, RL to 2.5V unless otherwise noted (Note 9). VOS CMRR AVOL Input Offset Voltage Input VOS Drift Input Offset Current Input Bias Current Input Voltage Range (High) Input Voltage Range (Low) Common Mode Rejection Ratio Large-Signal Voltage Gain VOUT Output Swing (High) IOS IB Output Swing (Low) IOUT ISC SR GBW IS Output Current Short-Circuit Current Slew Rate Gain Bandwidth Channel Separation Supply Current (Note 4) (Note 7) 4.5 mV µV/°C nA µA V V dB V/mV V/mV V V V V mA mA V/µs MHz dB mA TYP MAX UNITS 3 mV 10 30 µV/°C ● 10 ● ● ● VCM = 1.5V to 3.5V VOUT = 1.5V to 3.5V, RL = 500Ω VOUT = 1.5V to 3.5V, RL = 100Ω RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive VOUT = 3.5V or 1.5V, 30mV Overdrive VOUT = 2.5V, VIN = ±1V AV = – 1 (Note 5) f = 200kHz VOUT, 1.5V to 3.5V, RL = 100Ω Per Amplifier ● ● 3.5 ● 71 0.7 0.5 3.8 3.6 ● ● ● ● 1.5 1.2 1.4 ● ● ● ● ● ● ● 2.5 15 500 ±5 ±20 ±45 150 55 80 ● – 40°C ≤ TA ≤ 85°C. VS = ±5V, VCM = 0V unless otherwise noted (Notes 8, 9). SYMBOL PARAMETER CONDITIONS MIN VOS Input Offset Voltage (Note 4) ● Input VOS Drift (Note 7) ● IOS Input Offset Current ● 600 nA IB Input Bias Current ● ±6 µA 4 Powered by ICminer.com Electronic-Library Service CopyRight 2003 LT1813 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the temperature range – 40°C ≤ TA ≤ 85°C. VS = ±5V, VCM = 0V unless otherwise noted (Notes 8, 9). SYMBOL PARAMETER CONDITIONS MIN Input Voltage Range (High) Input Voltage Range (Low) ● ● 3.5 TYP MAX UNITS – 3.5 V V CMRR Common Mode Rejection Ratio VCM = ±3.5V ● 72 dB PSRR Power Supply Rejection Ratio VS = ±2V to ±5.5V VS = ±2V to ±6.5V (LT1813HV) ● ● 75 72 dB dB AVOL Large-Signal Voltage Gain VOUT = ±3V, RL = 500Ω VOUT = ±3V, RL = 100Ω ● ● 0.8 0.6 V/mV V/mV VOUT Output Swing RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive ● ● ±3.60 ±3.15 IOUT Output Current VOUT = ±3V, 30mV Overdrive ● ±30 mA ISC Short-Circuit Current VOUT = 0V, VIN = ±1V ● ±55 mA SR Slew Rate AV = – 1 (Note 5) ● 350 V/µs GBW Gain Bandwidth f = 200kHz ● 60 MHz Channel Separation VOUT, ±3V, RL = 100Ω ● 80 Supply Current Per Amplifier VS = ±6.5V (LT1813HV) ● ● 5.0 5.5 mA mA 3.5 mV IS V V dB – 40°C ≤ TA ≤ 85°C, VS = 5V, VCM = 2.5V, RL to 2.5V unless otherwise noted (Notes 8, 9). VOS Input Offset Voltage (Note 4) ● Input VOS Drift (Note 7) ● IOS Input Offset Current ● IB Input Bias Current ● Input Voltage Range (High) Input Voltage Range (Low) ● ● 10 30 µV/°C 600 nA ±6 µA 1.5 V V 3.5 CMRR Common Mode Rejection Ratio VCM = 1.5V to 3.5V ● 70 dB AVOL Large-Signal Voltage Gain VOUT = 1.5V to 3.5V, RL = 500Ω VOUT = 1.5V to 3.5V, RL = 100Ω ● ● 0.6 0.4 V/mV V/mV VOUT Output Swing (High) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive ● ● 3.7 3.5 V V Output Swing (Low) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive ● ● Output Current VOUT = 3.5V or 1.5V, 30mV Overdrive ● ±17 IOUT 1.3 1.5 V V mA ISC Short-Circuit Current VOUT = 2.5V, VIN = ±1V ● ±40 mA SR Slew Rate AV = – 1 (Note 5) ● 125 V/µs GBW Gain Bandwidth f = 200kHz ● 50 MHz Channel Separation VOUT, 1.5V to 3.5V, RL = 100Ω ● 79 dB Supply Current Per Amplifier ● IS Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Differential inputs of ±3V 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: Slew rate is measured between ±2V on the output with ±3V input for ±5V supplies and 2VP-P on the output with a 3VP-P input for single 5V supplies. Powered by ICminer.com Electronic-Library Service CopyRight 2003 5 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 LT1813C is guaranteed to meet specified performance from 0°C to 70°C and is designed, characterized and expected to meet these extended temperature limits, but is not tested at – 40°C and 85°C. The LT1813I is guaranteed to meet the extended temperature limits. Note 9: The LT1813D is 100% production tested at 25°C. It is designed, characterized and expected to meet the 0°C to 70°C specifications although it is not tested or QA sampled at these temperatures. The LT1813D is guaranteed functional from –40°C to 85°C but may not meet those specifications. 5 LT1813 U W TYPICAL PERFOR A CE CHARACTERISTICS Input Common Mode Range vs Supply Voltage Supply Current vs Temperature V+ 5 PER AMPLIFIER VS = ± 2.5V 2 1 –1.0 INPUT BIAS CURRENT (µA) INPUT COMMON MODE RANGE (V) VS = ± 5V 3 0 – 0.5 4 SUPPLY CURRENT (mA) Input Bias Current vs Common Mode Voltage –1.5 – 2.0 TA = 25°C ∆VOS < 1mV 2.0 1.5 1.0 TA = 25°C VS = ± 5V – 0.5 –1.0 –1.5 0.5 50 25 0 75 TEMPERATURE (°C) 100 V– 125 0 1 4 3 2 5 SUPPLY VOLTAGE (± V) 1813 G01 INPUT VOLTAGE NOISE (nV/√Hz) – 0.9 –1.0 –1.1 in 10 1 en 1 50 25 75 0 TEMPERATURE (°C) 100 10 125 100 1k 10k FREQUENCY (Hz) TA = 25°C – 0.5 VIN = 30mV OUTPUT VOLTAGE SWING (V) OPEN-LOOP GAIN (dB) 67.5 RL = 500Ω RL = 100Ω 65.0 62.5 67.5 VS = ± 2.5V 65.0 62.5 60 100 50 25 75 0 TEMPERATURE (°C) 100 125 1k LOAD RESISTANCE (Ω) Output Voltage Swing vs Load Current V+ – 0.5 RL = 500Ω RL = 100Ω 2.0 RL = 100Ω 1.5 1.0 RL = 500Ω Powered by ICminer.com Electronic-Library Service CopyRight 2003 1 4 3 2 5 SUPPLY VOLTAGE (± V) –1.0 –1.5 VS = ± 5V VIN = 30mV 85°C 25°C – 40°C – 2.0 2.0 1.5 1.0 0.5 V– 0 10k 1813 G06 – 2.0 1813 G07 6 VS = ± 5V 0.1 100k –1.0 –1.5 0.5 60.0 –50 –25 70.0 V+ VS = ± 5V VO = ± 3V 70.0 72.5 Output Voltage Swing vs Supply Voltage Open-Loop Gain vs Temperature 72.5 TA = 25°C 1813 G05 1813 G04 75.0 75.0 OUTPUT VOLTAGE SWING (V) INPUT BIAS CURRENT (µA) 10 TA = 25°C VS = ± 5V AV = 101 RS = 10k INPUT CURRENT NOISE (pA/√Hz) – 0.8 –1.2 – 50 – 25 Open-Loop Gain vs Resistive Load 100 VS = ± 5V 5.0 1813 G03 Input Noise Spectral Density – 0.7 0 2.5 – 2.5 INPUT COMMON MODE VOLTAGE (V) 1813 G02 Input Bias Current vs Temperature – 0.6 – 2.0 – 5.0 7 6 OPEN-LOOP GAIN (dB) 0 –50 –25 6 7 1813 G02 V– –60 –40 0 20 40 –20 OUTPUT CURRENT (mA) 60 1813 G09 LT1813 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Short-Circuit Current vs Temperature Settling Time vs Output Step VS = ± 5V 100 4 SOURCE 3 100 SINK 90 2 1 0 –1 VS = ± 5V AV = –1 RF = 500Ω CF = 3pF 0.1% SETTLING –2 –3 –4 –5 100 125 0 5 20 15 10 25 SETTLING TIME (ns) 0 –20 ±2.5V ±2.5V ±5V 40 ±5V 20 20 10 0 0 CROSSTALK (dB) 60 30 100k 1M 10M FREQUENCY (Hz) 100M –30 –40 –50 –60 1M 10M 100M FREQUENCY (Hz) –2 –50 –25 VS = ±2.5V –6 –8 –10 40 50 25 0 75 TEMPERATURE (°C) 4 2 VS = ±2.5V 38 125 100 Frequency Response vs Capacitive Load, AV = – 1 TA = 25°C AV = 2 RL = 100Ω 6 VS = ±5V 42 1813 G15 12 8 –4 VS = ±5V 0 –2 TA = 25°C AV = –1 V = ±5V 8 S RF = RG = 500Ω NO RL CL= 1000pF CL= 500pF CL= 200pF 4 CL= 100pF CL= 50pF CL= 0 0 –4 –4 –12 –14 1M 1000M Frequency Response vs Supply Voltage, AV = 2 VOLTAGE MAGNITUDE (dB) VOLTAGE MAGNITUDE (dB) 0 PHASE MARGIN VS = ±5V 1813 G14 6 2 GBW VS = ±2.5V 85 PHASE MARGIN VS = ±2.5V –90 100k –40 1000M Frequency Response vs Supply Voltage, AV = 1 TA = 25°C AV = 1 NO RL 95 –80 1813 G13 4 GBW VS = ± 5V 105 –70 –20 –10 10k 100M PHASE MARGIN (DEG) 80 40 1M 10M FREQUENCY (Hz) 115 TA = 25°C AV = 10 VIN = 0dBm RL = 100Ω –10 100 PHASE (DEG) GAIN (dB) 120 PHASE GAIN 100k Gain Bandwidth and Phase Margin vs Temperature Crosstalk vs Frequency 50 TA = 25°C VS = ± 5V 1813 G12 GAIN BANDWIDTH (MHz) 60 0.1 1813 G11 Gain and Phase vs Frequency TA = 25°C AV = –1 RF = RG = 500Ω AV = 1 1 0.001 10k 35 30 1813 G10 70 AV = 10 0.01 VOLTAGE MAGNITUDE (dB) 75 0 25 50 TEMPERATURE (°C) AV = 100 10 OUTPUT IMPEDANCE (Ω) 110 80 –50 –25 Output Impedance vs Frequency 5 OUTPUT STEP (V) OUTPUT SHORT-CIRCUIT CURRENT (mA) 120 10M 100M FREQUENCY (Hz) 500M –6 1M 1813 G16 Powered by ICminer.com Electronic-Library Service CopyRight 2003 –8 10M 100M FREQUENCY (Hz) 500M 1813 G17 1 10M FREQUENCY (Hz) 100M 200M 1813 G18 7 LT1813 U W TYPICAL PERFOR A CE CHARACTERISTICS 105 GBW RL = 100Ω 90 85 44 PHASE MARGIN RL = 100Ω 80 42 POWER SUPPLY REJECTION RATIO (dB) 95 PHASE MARGIN (DEG) GBW RL = 500Ω 40 PHASE MARGIN RL = 500Ω 1 4 3 5 2 SUPPLY VOLTAGE (±V) 6 TA = 25°C AV = 1 VS = ±5V 80 –PSRR +PSRR 60 40 20 7 Slew Rate vs Supply Voltage 10k 1M 100k FREQUENCY (Hz) 10M 20 1k 100M 400 300 TA =25°C AV = –1 V = ±5V 1000 RS = R = R = 500Ω F G L 350 SR + SR – 300 250 200 100M Slew Rate vs Input Level SLEW RATE (V/µs) SR – 500 10M 1200 TA =25°C AV = –1 V = ±1V 400 RIN= R = R = 500Ω F G L + 600 1M 100k FREQUENCY (Hz) 10k 1813 G21 Slew Rate vs Supply Voltage 450 SLEW RATE (V/µs) SLEW RATE (V/µs) 40 1813 G20 1000 SR 60 0 1k 1813 G19 TA =25°C 900 AV = –1 /2 V =V 800 RIN= R S(TOTAL) F G = RL = 500Ω 700 TA = 25°C VS = ±5V 80 0 38 0 Common Mode Rejection Ratio vs Frequency 100 100 TA = 25°C 100 GAIN BANDWIDTH (MHz) Power Supply Rejection Ratio vs Frequency COMMON MODE REJECTION RATIO (dB) Gain Bandwidth and Phase Margin vs Supply Voltage SR + 800 SR – 600 400 100 200 0 1 4 3 2 5 SUPPLY VOLTAGE (±V) 200 7 6 0 1 4 3 2 5 SUPPLY VOLTAGE (±V) SLEW RATE (V/µs) 800 TOTAL HARMONIC DISTORTION + NOISE (%) 1100 900 SR – VS = ± 5V 700 600 500 400 300 200 –50 SR – VS = ±2.5V SR + VS = ±2.5V –25 0 75 50 25 TEMPERATURE (°C) 100 1 2 4 3 5 6 INPUT LEVEL (VP-P) 9 AV = –1 0.005 AV = 1 0.002 TA = 25°C VS = ± 5V VO = 2VP-P RL = 500Ω 0.001 Powered by ICminer.com Electronic-Library Service CopyRight 2003 10 8 Undistorted Output Swing vs Frequency AV = – 1 8 125 7 1813 G24 0.01 1813 G25 8 0 Total Harmonic Distortion + Noise vs Frequency Slew Rate vs Temperature 1000 7 1813 G23 1813 G22 SR + VS = ± 5V 6 OUTPUT VOLTAGE (VP-P) 0 100 6 5 4 3 2 1 1k 10k FREQUENCY (Hz) 100k 1813 G26 AV = 1 7 VS = ± 5V RL = 100Ω 2% MAX DISTORTION 0 100k 1M 10M FREQUENCY (Hz) 100M 1813 G27 LT1813 U W TYPICAL PERFOR A CE CHARACTERISTICS AV = 2 VS = ± 5V VO = 2VP-P –50 2ND HARMONIC 3RD HARMONIC RL = 100Ω –60 –70 –80 3RD HARMONIC –90 2ND HARMONIC RL = 500Ω –100 100k 100 DIFFERENTIAL GAIN RL = 150Ω 0.4 90 0.3 80 DIFFERENTIAL GAIN RL = 1k 0.2 0.1 0.5 0 DIFFERENTIAL PHASE RL = 150Ω 0.4 0.3 0.2 10M AV = 1 70 60 50 AV = –1 40 30 10 0 0 1M FREQUENCY (Hz) TA = 25°C VS = ±5V 20 DIFFERENTIAL PHASE RL = 1k 0.1 DIFFERENTIAL GAIN (%) HARMONIC DISTORTION (dB) –40 Capacitive Load Handling 0.5 OVERSHOOT (%) –30 Differential Gain and Phase vs Supply Voltage DIFFERENTIAL PHASE (DEG) 2nd and 3rd Harmonic Distortion vs Frequency 4 1813 G28 Small-Signal Transient (AV = 1) 1813 G31 Large-Signal Transient (AV = 1) 1813 G34 Powered by ICminer.com Electronic-Library Service CopyRight 2003 10 8 6 TOTAL SUPPLY VOLTAGE (V) 12 10 100 1000 CAPACITIVE LOAD (pF) 10000 1813 G30 1813 G29 Small-Signal Transient (AV = –1) Small-Signal Transient (AV = 1, CL = 100pF) 1813 G32 Large-Signal Transient (AV = –1) 1813 G35 1813 G33 Large-Signal Transient (AV = –1, CL = 200pF) 1813 G36 9 LT1813 U W U U APPLICATIONS INFORMATION Layout and Passive Components Capacitive Loading The LT1813 amplifier is more tolerant of less than ideal layouts than other high speed amplifiers. For maximum performance (for example, fast settling) 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). The LT1813 is stable with a 1000pF capacitive load which is outstanding for a 100MHz amplifier. 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 so there will be peaking in the frequency domain and in the transient response. Coaxial cable can be driven 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. 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 oscillations. If feedback resistors greater than 2k are used, a parallel capacitor of value CF > RG • CIN/RF should be used to cancel the input pole and optimize dynamic performance. 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. Input Considerations Each of the LT1813 amplifier inputs is the base of an NPN and PNP transistor whose base currents are of opposite polarity and provide first-order bias current cancellation. Because of variation in the matching of NPN and PNP beta, the polarity of the input current can be positive or negative. The offset current does not depend on beta matching and is well controlled. The use of balanced source resistance at each input is recommended for applications where DC accuracy must be maximized. The inputs can withstand differential input voltages of up to 3V without damage and need no clamping or source resistance for protection. Differential inputs generate the large supply currents (up to 40mA) required for high slew rates. Typically, power dissipation does not significantly increase in normal, closed-loop operation because of the low duty cycle of the transient inputs. The device should not be used as a comparator because with sustained differential inputs, excessive power dissipation may result. 10 Powered by ICminer.com Electronic-Library Service CopyRight 2003 Slew Rate The slew rate is proportional to the differential input voltage. Highest slew rates are therefore seen in the lowest gain configurations. For example, a 5V output step in a gain of 10 has a 0.5V input step, whereas in unity gain there is a 5V input step. The LT1813 is tested for slew rate in a gain of – 1. Lower slew rates occur in higher gain configurations. Power Dissipation The LT1813 combines high speed and large output drive in a small package. It is possible to exceed the maximum junction temperature under certain conditions. Maximum junction temperature (TJ) is calculated from the ambient temperature (TA) and power dissipation (PD) as follows: LT1813CS8: TJ = TA + (PD • 150°C/W) 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 supply voltage). For each amplifier: PDMAX = (V + – V – )(ISMAX) + (V +/2)2/RL or PDMAX = (V + – V – )(ISMAX) + (V + – VOMAX)(VOMAX/RL) LT1813 U W U U APPLICATIONS INFORMATION Example: LT1813 in SO-8 at 70°C, VS = ±5V, RL = 100Ω PDMAX = (10V)(4.5mA) + (2.5V)2/100Ω = 108mW TJMAX = 70°C + (2 • 108mW)(150°C/W) = 102°C Circuit Operation The LT1813 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. The inputs are buffered by complementary NPN and PNP emitter followers which drive a 300Ω resistor. The input voltage appears across the resistor generating currents that are mirrored into the high impedance node. Complementary followers form an output stage that buffers the gain node from the load. The bandwidth is set by the input resistor and the capacitance on the high impedance node. 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. Highest slew rates are therefore seen in the lowest gain configurations. The RC network across the output stage is bootstrapped when the amplifier is driving a light or moderate load and has no effect under normal operation. When driving capacitive loads (or a low value resistive load) the network is incompletely bootstrapped and adds to the compensation at the high impedance node. The added capacitance slows down the amplifier which improves the phase margin by moving the unity-gain cross away from the pole formed by the output impedance and the capacitive load. The zero created by the RC combination adds phase to ensure that the total phase lag does not exceed 180 degrees (zero phase margin) and the amplifier remains stable. In this way, the LT1813 is stable with up to 1000pF capacitive loads in unity gain, and even higher capacitive loads in higher closed-loop gain configurations. W W SI PLIFIED SCHEMATIC V+ R1 300Ω +IN RC CC OUT –IN C V– 1813 SS 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 representationCopyRight that the interconnection of its circuits as described herein will not infringe on existing patent rights. Powered by ICminer.com Electronic-Library Service 2003 11 LT1813 U TYPICAL APPLICATION Two Op Amp Instrumentation Amplifier R5 220Ω R1 10k R4 10k R2 1k R3 1k – 1/2 LT1813 – 1/2 LT1813 + – VOUT + VIN + ( R4 1 R2 R3 R2 + R3 GAIN = 1 + + + R5 R3 2 R1 R4 ) = 102 TRIM R5 FOR GAIN TRIM R1 FOR COMMON MODE REJECTION BW = 1MHz 1813 TA03 U PACKAGE DESCRIPTION MS8 Package 8-Lead Plastic MSOP S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1660) (LTC DWG # 05-08-1610) 0.118 ± 0.004* (3.00 ± 0.102) 0.189 – 0.197* (4.801 – 5.004) 8 8 7 6 0.118 ± 0.004** (3.00 ± 0.102) 0.193 ± 0.006 (4.90 ± 0.15) 1 2 3 5 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) SEATING PLANE 0.012 (0.30) 0.0256 REF (0.65) BSC 1 0.034 ± 0.004 (0.86 ± 0.102) 0° – 6° TYP 0.021 ± 0.006 (0.53 ± 0.015) 6 4 0.040 ± 0.006 (1.02 ± 0.15) 0.007 (0.18) 7 5 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.006 ± 0.004 (0.15 ± 0.102) MSOP (MS8) 1098 * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 2 3 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 4 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC SO8 1298 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1360/LT1361/LT1362 Single/Dual/Quad 50MHz, 800V/µs, C-LoadTM Amplifiers ±15V Operation, 1mV Max VOS, 1µA Max IB LT1363/LT1364/LT1365 Single/Dual/Quad 70MHz, 1000V/µs C-Load Amplifiers ±15V Operation, 1.5mV Max VOS, 2µA Max IB LT1398/LT1399 Dual/Triple 300MHz Current Feedback Amplifiers 4.5mA Supply Current, 80mA Output Current, Shutdown C-Load is a trademark of Linear Technology Corporation. 12 Linear Technology Corporation 1813fa LT/LCG 0600 2K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 Powered by ICminer.com Electronic-Library Service CopyRight 2003 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com LINEAR TECHNOLOGY CORPORATION 1999