LT1812 3mA, 100MHz, 750V/µs Operational Amplifier with Shutdown DESCRIPTION FEATURES n n n n n n n n n n n n n n n 100MHz Gain Bandwidth 750V/μs Slew Rate 3.6mA Maximum Supply Current 50μA Supply Current in Shutdown 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 30ns Settling Time to 0.1%, 5V Step Specified at ±5V, Single 5V Supplies Operating Temperature Range: –40°C to 85°C Low Profile (1mm) SOT-23 (ThinSOT™ ) and S8 Packages The LT®1812 is a low power, high speed, very high slew rate operational amplifier with excellent DC performance. The LT1812 features reduced supply current, lower input offset voltage, lower input bias current and higher DC gain than other devices with comparable bandwidth. A power saving shutdown feature reduces supply current to 50μA. The circuit topology is a voltage feedback amplifier with the slewing characteristics of a current feedback amplifier. 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. The LT1812 is manufactured on Linear Technology’s advanced low voltage complementary bipolar process. The dual version is the LT1813. For higher supply voltage single, dual and quad operational amplifiers with up to 70MHz gain bandwidth, see the LT1351 through LT1365 data sheets. APPLICATIONS n n n n n n Wideband Amplifiers Buffers Active Filters Video and RF Amplification Cable Drivers Data Acquisition Systems L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. ThinSOT is a Trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Filter Frequency Response 10 4MHz, 4th Order Butterworth Filter 0 232Ω 232Ω 665Ω VIN – 47pF 274Ω 220pF + 562Ω LT1812 470pF – + 22pF LT1812 VOUT VOLTAGE GAIN (dB) –10 274Ω –20 –30 –40 –50 –60 –70 1812 TA01 –80 –90 0.1 VS = ±5V VIN = 600mVP-P PEAKING < 0.12dB 1 10 FREQUENCY (MHz) 100 1812 TA02 1812fb 1 LT1812 ABSOLUTE MAXIMUM RATINGS (Note 1) Total Supply Voltage (V + to V –) ..............................12.6V Differential Input Voltage (Transient Only, Note 2) ......±3V Input Voltage, Shutdown Voltage...............................±VS Output Short-Circuit Duration (Note 3) ............. Indefinite Operating Temperature Range (Note 8)..... – 40°C to 85°C Specified Temperature Range (Note 8) .................................................... –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 PIN CONFIGURATION TOP VIEW TOP VIEW TOP VIEW 5 V+ VOUT 1 V– 2 V– 2 +IN 3 6 V+ VOUT 1 + – +IN 3 4 –IN 5 SHDN + – 4 –IN S6 PACKAGE 6-LEAD PLASTIC TSOT-23 TJMAX = 150°C, θJA = 230°C/ W (NOTE 9) S5 PACKAGE 5-LEAD PLASTIC TSOT-23 TJMAX = 150°C, θJA = 250°C/ W (NOTE 9) NC 1 8 SHDN –IN 2 – 7 V+ +IN 3 + 6 VOUT 5 NC V– 4 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/ W (NOTE 9) ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1812CS5#PBF LT1812CS5#TRPBF LTLH 5-Lead Plastic TSOT-23 0°C to 70°C LT1812IS5#PBF LT1812IS5#TRPBF LTLJ 5-Lead Plastic TSOT-23 –40°C to 85°C LT1812CS6#PBF LT1812CS6#TRPBF LTLK 6-Lead Plastic TSOT-23 0°C to 70°C LT1812IS6#PBF LT1812IS6#TRPBF LTLL 6-Lead Plastic TSOT-23 –40°C to 85°C LT1812CS8#PBF LT1812CS8#TRPBF 1812 8-Lead Plastic SO 0°C to 70°C LT1812IS8#PBF LT1812IS8#TRPBF 1812I 8-Lead Plastic SO –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ 1812fb 2 LT1812 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER VOS Input Offset Voltage IOS Input Offset Current TA = 25°C, VS = ± 5V, VCM = 0V unless otherwise noted (Note 10). CONDITIONS MIN (Note 4) TYP MAX 0.4 1.5 UNITS mV 30 400 nA – 0.9 ±4 IB Input Bias Current en Input Noise Voltage Density f = 10kHz 8 nV/√Hz in Input Noise Current Density f = 10kHz 1 pA/√Hz RIN Input Resistance VCM = ±3.5V Differential CIN Input Capacitance VCM Input Voltage Range (Positive) Input Voltage Range (Negative) CMRR Common Mode Rejection Ratio 3 3.5 VCM = ±3.5V 75 Minimum Supply Voltage μA 10 1.5 MΩ MΩ 2 pF 4.2 –4.2 –3.5 85 ±1.25 V V dB ±2 V PSRR Power Supply Rejection Ratio VS = ±2V to ±5.5V 78 97 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 Maximum Output Swing RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive ±3.80 ±3.35 ±4.0 ±3.5 V V IOUT Maximum Output Current VOUT = ±3V, 30mV Overdrive ±40 ±60 mA ISC Output Short-Circuit Current VOUT = 0V, 1V Overdrive (Note 3) ± 75 ±110 mA SR Slew Rate AV = –1 (Note 5) 500 750 V/μs FPBW Full Power Bandwidth 3V Peak (Note 6) 40 MHz GBW Gain Bandwidth Product f = 200kHz 75 100 MHz tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V, RL = 100Ω OS Overshoot AV = 1, 0.1V, RL = 100Ω 25 % tPD Propagation Delay AV = 1, 50% VIN to 50% VOUT, 0.1V, RL = 100Ω 2.8 ns ts Settling Time 5V Step, 0.1%, AV = – 1 30 ns THD Total Harmonic Distortion f = 1MHz, VOUT = 2VP-P, AV = 2, RL = 500Ω –76 dB Differential Gain VOUT = 2VP-P, AV = 2, RL = 150Ω 0.12 % ROUT ISHDN IS 2 ns Differential Phase VOUT = 2VP-P, AV = 2, RL = 150Ω 0.07 DEG Output Resistance AV = 1, f = 1MHz 0.4 Ω SHDN Pin Current SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) Supply Current –100 SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) 0 –50 ±1 μA μA 3 50 3.6 100 mA μA TYP MAX UNITS TA = 25°C, VS = 5V, VCM = 2.5V, RL to 2.5V unless otherwise noted (Note 10). SYMBOL PARAMETER CONDITIONS (Note 4) MIN VOS Input Offset Voltage IOS Input Offset Current IB Input Bias Current en Input Noise Voltage Density f = 10kHz 8 nV/√Hz in Input Noise Current Density f = 10kHz 1 pA/√Hz RIN Input Resistance VCM = 1.5V to 3.5V Differential 3 0.5 2.0 mV 30 400 nA –1.0 ±4 μA 10 1.5 MΩ MΩ 1812fb 3 LT1812 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER CIN Input Capacitance VCM Input Voltage Range (Positive) Input Voltage Range (Negative) TA = 25°C, VS = ± 5V, VCM = 0V unless otherwise noted (Note 10). CONDITIONS MIN TYP MAX 2 3.5 4 1 UNITS pF 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 Maximum Output Swing (Positive) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive 3.9 3.7 4.1 3.9 V V Maximum Output Swing (Negative) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive IOUT Maximum Output Current VOUT = 3.5V or 1.5V, 30mV Overdrive ± 25 ±40 mA ISC Output Short-Circuit Current VOUT = 2.5V, 1V Overdrive (Note 3) ±55 ±80 mA SR Slew Rate AV = –1 (Note 5) 200 350 V/μs FPBW Full Power Bandwidth 1V Peak (Note 6) 55 MHz GBW Gain Bandwidth Product f = 200kHz 94 MHz 0.9 1.1 65 1.1 1.3 V V tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V, RL = 100Ω 2.1 ns OS Overshoot AV = 1, 0.1V, RL = 100Ω 25 % tPD Propagation Delay AV = 1, 50% VIN to 50% VOUT , 0.1V, RL = 100Ω 3 ns ts Settling Time 2V Step, 0.1%, AV = –1 30 ns THD Total Harmonic Distortion f = 1MHz, VOUT = 2VP-P, AV = 2, RL = 500Ω –75 dB Differential Gain VOUT = 2VP-P, AV = 2, RL = 150Ω 0.22 % Differential Phase VOUT = 2VP-P, AV = 2, RL = 150Ω 0.21 DEG Output Resistance AV = 1, f = 1MHz 0.45 Ω SHDN Pin Current SHDN > V – + 2.0V (On) (Note 11) SHDN < V– + 0.4V (Off) (Note 11) ROUT ISHDN IS Supply Current –50 SHDN > V– + 2.0V (On) (Note 11) SHDN < V– + 0.4V (Off) (Note 11) 0 –20 ±1 μA μA 2.7 20 3.6 50 mA μA TYP MAX 0°C ≤ TA ≤ 70°C, VS = ± 5V, VCM = 0V unless otherwise noted (Note 10). SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 4) ΔVOS/ΔT Input Offset Voltage Drift (Note 7) MIN 10 UNITS 2 mV 15 μV/°C IOS Input Offset Current 500 nA IB Input Bias Current ±5 μA VCM Input Voltage Range (Positive) Input Voltage Range (Negative) –3.5 V V CMRR Common Mode Rejection Ratio 3.5 VCM = ±3.5V 73 Minimum Supply Voltage dB ±2 V PSRR Power Supply Rejection Ratio VS = ±2V to ±5.5V 76 dB AVOL Large-Signal Voltage Gain VOUT = ±3V, RL = 500Ω VOUT = ±3V, RL = 100Ω 1.0 0.7 V/mV V/mV VOUT Maximum Output Swing RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive ±3.70 ±3.25 IOUT Maximum Output Current VOUT = ±3V, 30mV Overdrive ±35 V V mA 1812fb 4 LT1812 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER 0°C ≤ TA ≤ 70°C, VS = ± 5V, VCM = 0V unless otherwise noted (Note 10). CONDITIONS MIN ISC Output Short-Circuit Current VOUT = 0V, 1V Overdrive (Note 3) ±60 TYP MAX UNITS mA SR Slew Rate AV = –1 (Note 5) 400 V/μs GBW Gain Bandwidth Product f = 200kHz 65 MHz ISHDN SHDN Pin Current SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) IS Supply Current ± 1.5 μA μA 4.6 150 mA μA MAX UNITS –150 SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) 0°C ≤ TA ≤ 70°C, VS = 5V, VCM = 2.5V, RL to 2.5V unless otherwise noted (Note 10). SYMBOL PARAMETER CONDITIONS MIN TYP VOS Input Offset Voltage (Note 4) ΔVOS/ΔT Input Offset Voltage Drift (Note 7) IOS Input Offset Current 500 nA IB Input Bias Current ±5 μA VCM Input Voltage Range (Positive) Input Voltage Range (Negative) 1.5 V V 10 2.5 mV 15 μV/°C 3.5 CMRR Common Mode Rejection Ratio VCM = 1.5V to 3.5V 71 dB AVOL Large-Signal Voltage Gain VOUT = 1.5V to 3.5V, RL = 500Ω VOUT = 1.5V to 3.5V, RL = 100Ω 0.7 0.5 V/mV V/mV VOUT Maximum Output Swing (Positive) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive 3.8 3.6 V V Maximum Output Swing (Negative) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive IOUT Maximum Output Current VOUT = 3.5V or 1.5V, 30mV Overdrive ISC Output Short-Circuit Current VOUT = 2.5V, 1V Overdrive (Note 3) ±45 mA SR Slew Rate AV = –1 (Note 5) 150 V/μs GBW Gain Bandwidth Product f = 200kHz 55 MHz SHDN Pin Current SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) –75 ISHDN IS Supply Current 1.2 1.4 ±20 V V mA SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) ±1.5 μA μA 4.5 75 mA μA – 40°C ≤ TA ≤ 85°C. VS = ±5V, VCM = 0V unless otherwise noted (Notes 8, 10). SYMBOL VOS PARAMETER CONDITIONS Input Offset Voltage (Note 4) ΔVOS/ΔT Input Offset Voltage Drift MIN (Note 7) TYP 10 MAX UNITS 3 mV 30 μV/°C IOS Input Offset Current 600 nA IB Input Bias Current ±6 μA VCM Input Voltage Range (Positive) Input Voltage Range (Negative) –3.5 V V CMRR Common Mode Rejection Ratio 3.5 VCM = ±3.5V 72 Minimum Supply Voltage dB ±2 V PSRR Power Supply Rejection Ratio VS = ±2V to ±5.5V 75 dB AVOL Large-Signal Voltage Gain VOUT = ±3V, RL = 500Ω VOUT = ±3V, RL = 100Ω 0.8 0.6 V/mV V/mV 1812fb 5 LT1812 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER – 40°C ≤ TA ≤ 85°C. VS = ±5V, VCM = 0V unless otherwise noted (Notes 8, 10). CONDITIONS MIN VOUT Maximum Output Swing RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive ±3.60 ±3.15 IOUT Maximum Output Current VOUT = ±3V, 30mV Overdrive ±30 ISC Output Short-Circuit Current VOUT = 0V, 1V Overdrive (Note 3) ±55 mA SR Slew Rate AV = –1 (Note 5) 350 V/μs GBW Gain Bandwidth Product f = 200kHz 60 MHz SHDN Pin Current SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) ISHDN IS Supply Current TYP MAX UNITS V V mA ±2 μA μA 5 200 mA μA MAX UNITS –200 SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) – 40°C ≤ TA ≤ 85°C, VS = 5V, VCM = 2.5V, RL to 2.5V unless otherwise noted (Notes 8, 10). SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 4) ΔVOS/ΔT Input Offset Voltage Drift (Note 7) IOS Input Offset Current IB Input Bias Current VCM Input Voltage Range (Positive) Input Voltage Range (Negative) MIN TYP 10 3.5 mV 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 = 2.0V to 3.0V, RL = 100Ω 0.6 0.4 V/mV V/mV VOUT Maximum Output Swing (Positive) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive 3.7 3.5 V V Maximum Output Swing (Negative) RL = 500Ω, 30mV Overdrive RL = 100Ω, 30mV Overdrive IOUT Maximum Output Current VOUT = 3.5V or 1.5V, 30mV Overdrive ±17 mA ISC Output Short-Circuit Current VOUT = 2.5V, 1V Overdrive (Note 3) ±40 mA 1.3 1.5 V V SR Slew Rate AV = –1 (Note 5) 125 V/μs GBW Gain Bandwidth Product f = 200kHz 50 MHz ISHDN SHDN Pin Current SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) IS Supply Current SHDN > V – + 2.0V (On) (Note 11) SHDN < V – + 0.4V (Off) (Note 11) Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: 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. Note 6: Full power bandwidth is calculated from the slew rate: FPBW = SR/2πVP. Note 7: This parameter is not 100% tested. ±2 μA μA 5 100 mA μA –100 Note 8: The LT1812C is guaranteed to meet specified performance from 0°C to 70°C. The LT1812C is designed, characterized and expected to meet specified performance from –40°C to 85°C but is not tested or QA sampled at these temperatures. The LT1812I is guaranteed to meet specified performance from –40°C to 85°C. Note 9: Thermal resistance varies with the amount of PC board metal connected to the package. The nominal values are for short traces connected to the pins. The thermal resistance can be substantially reduced by connecting Pin 2 of the 5-lead or 6-lead TSOT-23 or Pin 4 of the SO-8 to a large metal area. Note 10: For the 8-lead SO and 6-lead TSOT-23 parts, the electrical characteristics apply to the “ON” state, unless otherwise noted. These parts are in the “ON” state when either SHDN is not connected, or SHDN > V – + 2.0V. Note 11: The shutdown (SHDN) feature is not available on the 5-lead SOT-23 parts. These parts are always in the “ON” state. 1812fb 6 LT1812 TYPICAL PERFORMANCE CHARACTERISTICS Input Common Mode Range vs Supply Voltage Supply Current vs Temperature V+ 4 VS = ±5V 3 VS = ±2.5V 2 1 0 –0.5 –1.0 INPUT BIAS CURRENT (μA) INPUT COMMON MODE RANGE (V) 5 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 –25 50 25 0 75 TEMPERATURE (°C) 100 V– 125 0 1 4 3 2 5 SUPPLY VOLTAGE (±V) 1812 G01 INPUT VOLTAGE NOISE (nV/√Hz) –0.6 VS = ±5V –1.0 VS = ±2.5V –1.2 –1.4 –50 –25 in 1 10 en 100 125 10 100 1k 10k FREQUENCY (Hz) TA = 25°C –0.5 VIN = 30mV OUTPUT VOLTAGE SWING (V) OPEN-LOOP GAIN (dB) RL = 500Ω RL = 100Ω 65.0 62.5 –1.5 60 100 100 125 1812 G07 1k LOAD RESISTANCE (Ω) V+ –0.5 RL = 500Ω –2.0 2.0 RL = 100Ω 1.5 1.0 RL = 500Ω 0 1 4 3 2 5 SUPPLY VOLTAGE (±V) 10k Output Voltage Swing vs Load Current RL = 100Ω V– 50 25 75 0 TEMPERATURE (°C) VS = ±2.5V 65.0 1812 G06 –1.0 0.5 60.0 –50 –25 67.5 62.5 V+ VS = ±5V VO = ±3V 67.5 VS = ±5V Output Voltage Swing vs Supply Voltage Open-Loop Gain vs Temperature 70.0 70.0 1812 G05 1812 G04 72.5 TA = 25°C 72.5 0.1 100k 1 50 25 75 0 TEMPERATURE (°C) 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) –0.4 75.0 Open-Loop Gain vs Resistive Load 100 0 5.0 1812 G03 Input Noise Spectral Density –0.2 0 2.5 –2.5 INPUT COMMON MODE VOLTAGE (V) 1812 G02 Input Bias Current vs Temperature –0.8 –2.0 –5.0 7 6 OPEN-LOOP GAIN (dB) 0 –50 –1.0 –1.5 VS = ±5V VIN = 30mV 85°C 25°C –40°C –2.0 2.0 1.5 1.0 0.5 6 7 1812 G08 V– –60 –40 0 20 40 –20 OUTPUT CURRENT (mA) 60 1812 G09 1812fb 7 LT1812 TYPICAL PERFORMANCE CHARACTERISTICS 70 VS = ±5V SOURCE TA = 25°C AV = –1 RF = RG = 500Ω 60 115 Gain vs Frequency GAIN (dB) SINK 105 100 95 60 ±5V ±2.5V 40 30 ±2.5V ±5V 20 20 10 0 –4 –6 100 125 1M 10M FREQUENCY (Hz) 100k 100M 0 –1 TA = 25°C VS = ±5V AV = –1 RF = 500Ω CF = 3pF 0.1% SETTLING –4 –5 0 5 90 GBW RL = 100Ω 70 45 PHASE MARGIN RL = 100Ω 40 30 5 4 3 SUPPLY VOLTAGE (±V) 1 0 35 6 2 100 115 AV = 10 AV = 1 0.1 –6 1M 35 1812 G12 500M Gain vs Frequency 12 GBW VS = ±5V 105 GBW VS = ±2.5V 95 85 40 PHASE MARGIN VS = ±5V –50 –25 50 25 0 75 TEMPERATURE (°C) 100 TA = 25°C AV = –1 V = ±5V 8 S RF = RG = 500Ω NO RL CL= 500pF CL= 200pF 36 125 –8 CL= 100pF CL= 50pF CL= 0 0 –4 1812 G15 CL= 1000pF 4 38 PHASE MARGIN VS = ±2.5V TA = 25°C VS = ±5V 100M 10M 100M FREQUENCY (Hz) 1812 G17 RL = 500Ω 0.01 10M 100k 1M FREQUENCY (Hz) VS = ±5V –2 7 PHASE MARGIN (DEG) GAIN BANDWIDTH (MHz) AV = 100 10k VS = ±2.5V 0 Gain Bandwidth and Phase Margin vs Temperature Output Impedance vs Frequency 0.001 2 1812 G19 1812 G11 1 4 –4 PHASE MARGIN RL = 500Ω 20 15 10 25 SETTLING TIME (ns) TA = 25°C AV = 2 RL = 100Ω 6 GAIN (dB) GAIN BANDWIDTH (MHz) 1 GBW RL = 500Ω PHASE MARGIN (DEG) 2 500M Gain vs Frequency 8 TA = 25°C 4 3 10M 100M FREQUENCY (Hz) 1812 G16 Gain Bandwidth and Phase Margin vs Supply Voltage 110 –3 –14 1M 1812 G13 5 –2 –12 –40 1000M GAIN (dB) 50 25 75 0 TEMPERATURE (°C) –10 10k Settling Time vs Output Step OUTPUT STEP (V) VS = ±5V –2 –10 –20 0 1812 G10 10 0 PHASE 40 VS = ±2.5V –8 90 –50 –25 OUTPUT IMPEDANCE (Ω) 2 80 GAIN TA = 25°C AV = 1 NO RL 4 100 50 110 6 120 PHASE (DEG) OUTPUT SHORT-CIRCUIT CURRENT (mA) 120 Open-Loop Gain and Phase vs Frequency GAIN (dB) Output Short-Circuit Current vs Temperature 1 10M FREQUENCY (Hz) 100M 200M 1812 G18 1812fb 8 LT1812 TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Supply Current vs Temperature 100 60 VS = ±5V 50 40 30 VS = ±2.5V 20 10 0 –50 –25 100 TA = 25°C AV = 1 VS = ±5V 80 –PSRR 60 +PSRR 40 20 100 60 40 20 0 125 1k 1M 100k FREQUENCY (Hz) 10k 10M 100M Slew Rate vs Supply Voltage 700 600 500 10M TA =25°C AV = –1 V = ±5V 1000 RS = R = R = 500Ω F G L SR– 400 SR+ 300 400 100M Slew Rate vs Input Level SLEW RATE (V/μs) SLEW RATE (V/μs) SR+ 100k 1M FREQUENCY (Hz) 1200 TA =25°C AV = –1 VIN = ±1V 500 RF = RG = RL = 500Ω SR– 10k 1812 G21 Slew Rate vs Supply Voltage 600 800 1k 1812 G20 1200 TA =25°C 1100 AV = –1 /2 V =V 1000 RIN= R S(TOTAL) F G = RL = 500Ω 900 TA = 25°C VS = ±5V 80 0 50 25 75 0 TEMPERATURE (°C) 1812 G14 SLEW RATE (V/μs) Common Mode Rejection Ratio vs Frequency COMMON MODE REJECTION RATIO (dB) VSHDN = V– + 0.4V POWER SUPPLY REJECTION RATIO (dB) SHUTDOWN SUPPLY CURRENT (μA) 70 Power Supply Rejection Ratio vs Frequency 800 SR– SR+ 600 400 300 200 0 1 4 3 2 5 SUPPLY VOLTAGE (±V) 0 7 6 1 4 3 2 5 SUPPLY VOLTAGE (±V) SLEW RATE (V/μs) TOTAL HARMONIC DISTORTION + NOISE (%) 1200 SR+ VS = ±5V 800 600 SR– VS = ±2.5V 400 200 0 –50 –25 SR+ VS = ±2.5V 50 25 75 0 TEMPERATURE (°C) 0 100 125 1812 G25 1 2 4 3 5 6 INPUT LEVEL (VP-P) 9 AV = –1 8 AV = –1 0.005 AV = 1 0.002 TA = 25°C VS = ±5V VO = 2VP-P RL = 500Ω 10 8 Undistorted Output Swing vs Frequency 0.01 0.001 7 1812 G24 Total Harmonic Distortion + Noise vs Frequency Slew Rate vs Temperature 1000 200 7 1812 G23 1812 G22 SR– VS = ±5V 6 OUTPUT VOLTAGE (VP-P) 200 100 6 5 4 3 2 1 1k 10k FREQUENCY (Hz) 100k 1812 G26 AV = 1 7 TA = 25°C VS = ±5V RL = 100Ω 2% MAX DISTORTION 0 100k 1M 10M FREQUENCY (Hz) 100M 1812 G27 1812fb 9 LT1812 TYPICAL PERFORMANCE CHARACTERISTICS –50 DIFFERENTIAL GAIN RL = 150Ω 2ND HARMONIC 3RD HARMONIC RL = 100Ω –60 –70 –80 3RD HARMONIC –90 2ND HARMONIC RL = 500Ω –100 100k Capacitive Load Handling 1M FREQUENCY (Hz) 0.20 90 0.15 80 0.05 0.25 0 DIFFERENTIAL PHASE RL = 150Ω 0.20 0.15 DIFFERENTIAL PHASE RL = 1k 0.10 TA = 25°C VS = ±5V AV = 1 70 60 50 AV = –1 40 30 20 10 0.05 10M 100 0.10 DIFFERENTIAL GAIN RL = 1k 0 0.25 DIFFERENTIAL GAIN (%) HARMONIC DISTORTION (dB) –40 TA = 25°C AV = 2 VS = ±5V VO = 2VP-P DIFFERENTIAL PHASE (DEG) –30 Differential Gain and Phase vs Supply Voltage OVERSHOOT (%) 2nd and 3rd Harmonic Distortion vs Frequency TA = 25°C 4 10 8 6 TOTAL SUPPLY VOLTAGE (V) 1812 G28 0 12 10 100 1000 CAPACITIVE LOAD (pF) 10000 1812 G30 1812 G29 Small-Signal Transient, AV = –1 Small-Signal Transient, AV = 1 Small-Signal Transient, AV = 1, CL = 1000pF Large-Signal Transient, AV = –1 Large-Signal Transient, AV = 1 Large-Signal Transient, AV = 1, CL = 1000pF 1812fb 10 LT1812 APPLICATIONS INFORMATION Layout and Passive Components The LT1812 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 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 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. 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. 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 LT1812 is tested for slew rate in a gain of – 1. Lower slew rates occur in higher gain configurations. Shutdown The device should not be used as a comparator because with sustained differential inputs, excessive power dissipation may result. The LT1812 has a shutdown pin (SHDN, Pin 8) for conserving power. When this pin is open or biased at least 2V above the negative supply, the part operates normally. When pulled down to V –, the supply current drops to about 50μA. Typically, the turn-off delay is 1μs and the turn-on delay 0.5μs. The current out of the SHDN pin is also typically 50μA. In shutdown mode, the amplifier output is not isolated from the inputs, so the LT1812 shutdown feature cannot be used for multiplexing applications. The 50μA typical shutdown current is exclusive of any output (load) current. In order to prevent load current (and maximize the power savings), either the load needs to be disconnected, or the input signal needs to be 0V. Even in shutdown mode, the LT1812 can still drive significant current into a load. For example, in an AV = 1 configuration, when driven with a 1V DC input, the LT1812 drives 2mA into a 100Ω load. It takes about 500μs for the load current to reach this value. Capacitive Loading Power Dissipation The LT1812 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 LT1812 combines high speed and large output drive in a small package. It is possible to exceed the maximum junction temperature under certain conditions. Maximum Input Considerations Each of the LT1812 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 bias 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. 1812fb 11 LT1812 APPLICATIONS INFORMATION junction temperature (TJ) is calculated from the ambient temperature (TA) and power dissipation (PD) as follows: TJ = TA + (PD • θJA) (Note 9) 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 worstcase 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). Therefore PDMAX is: PDMAX = (V + – V– )(ISMAX) + (V +/2)2/RL or PDMAX = (V+ – V– )(ISMAX) + (V + – VOMAX)(VOMAX/RL) Example: LT1812CS5 at 70°C, VS = ± 5V, RL = 100Ω PDMAX = (10V)(4.5mA) + (2.5V)2/100Ω = 108mW TJMAX = 70°C + (108mW)(250°C/W) = 97°C Circuit Operation The LT1812 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 that 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 LT1812 is stable with up to 1000pF capacitive loads in unity gain, and even higher capacitive loads in higher closed-loop gain configurations. SIMPLIFIED SCHEMATIC V+ RB R1 300Ω +IN RC CC OUT –IN C BIAS CONTROL SHDN V– 1812 SS 1812fb 12 LT1812 PACKAGE DESCRIPTION S5 Package 5-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1635) 0.62 MAX 0.95 REF 2.90 BSC (NOTE 4) 1.22 REF 1.4 MIN 3.85 MAX 2.62 REF 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 TYP 5 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 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. JEDEC PACKAGE REFERENCE IS MO-193 1.90 BSC S5 TSOT-23 0302 REV B 1812fb 13 LT1812 PACKAGE DESCRIPTION S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 0.62 MAX 2.90 BSC (NOTE 4) 0.95 REF 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) 1.90 BSC S6 TSOT-23 0302 REV B 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. JEDEC PACKAGE REFERENCE IS MO-193 1812fb 14 LT1812 PACKAGE DESCRIPTION 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 .245 MIN 7 6 5 .160 ±.005 .150 – .157 (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) .030 ±.005 TYP 1 RECOMMENDED SOLDER PAD LAYOUT .010 – .020 s 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) 3 4 .053 – .069 (1.346 – 1.752) .004 – .010 (0.101 – 0.254) 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 2 .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) .050 (1.270) BSC SO8 0303 1812fb 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 LT1812 TYPICAL APPLICATION Single 5V Supply 10MS/s 12-Bit ADC Buffer VIN 2VP-P 2.5VDC + 12 BITS 68Ω LT1812 LTC1420 10MS/s 470pF – 1812 TA03 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1360/LT1361/LT1362 Single/Dual/Quad 50MHz, 800V/μs, C-Load™ Amplifiers 4mA Supply Current, 1mV Max VOS, 1μA Max IB LT1363/LT1364/LT1365 Single/Dual/Quad 70MHz, 1000V/μs, C-Load Amplifiers 50mA Output Current, 1.5mV Max VOS, 2μA Max IB LT1395/LT1396/LT1397 Single/Dual/Quad 400MHz Current Feedback Amplifiers 4.6mA Supply Current, 800V/μs, 80mA Output Current LT1806 325MHz, 140V/μs Rail-to-Rail I/O Op Amp Low Noise 3.5nV/√Hz LT1809 180MHz, 350V/μs Rail-to-Rail I/O Op Amp Low Distortion –90dBc at 5MHz LT1813 Dual 3mA, 100MHz, 750V/μs Operational Amplifier Dual Version of the LT1812 C-Load is a trademark of Linear Technology Corporation. 1812fb 16 Linear Technology Corporation LT 0909 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 1999