LT1352/LT1353 Dual and Quad 250µA, 3MHz, 200V/µs Operational Amplifiers U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The LT ®1352/LT1353 are dual and quad, very low power, high speed operational amplifiers with outstanding AC and DC performance. The amplifiers feature much lower supply current and higher slew rate than devices with comparable bandwidth. The circuit combines the slewing performance of a current feedback amplifier in a true operational amplifier with matched high impedance inputs. The high slew rate ensures that the large-signal bandwidth is not degraded. Each output is capable of driving a 1kΩ load to ±13V with ±15V supplies and a 500Ω load to ±3.4V on ±5V supplies. 3MHz Gain Bandwidth 200V/µs Slew Rate 250µA Supply Current per Amplifier C-LoadTM Op Amp Drives All Capacitive Loads Unity-Gain Stable Maximum Input Offset Voltage: 600µV Maximum Input Bias Current: 50nA Maximum Input Offset Current: 15nA Minimum DC Gain, RL = 2k: 30V/mV Input Noise Voltage: 14nV/√Hz Settling Time to 0.1%, 10V Step: 700ns Settling Time to 0.01%, 10V Step: 1.25µs Minimum Output Swing into 1k: ±13V Minimum Output Swing into 500Ω: ±3.4V Specified at ±2.5V, ±5V and ±15V The LT1352/LT1353 are members of a family of fast, high performance amplifiers using this unique topology and employing Linear Technology Corporation’s advanced complementary bipolar processing. For higher bandwidth devices with higher supply current see the LT1354 through LT1365 data sheets. Bandwidths of 12MHz, 25MHz, 50MHz and 70MHz are available with 1mA, 2mA, 4mA and 6mA of supply current per amplifier. Singles, duals and quads of each amplifier are available. U APPLICATIONS ■ ■ ■ ■ ■ ■ Battery-Powered Systems Wideband Amplifiers Buffers Active Filters Data Acquisition Systems Photodiode Amplifiers , LTC and LT are registered trademarks of Linear Technology Corporation. C-Load is a trademark of Linear Technology Corporation. U TYPICAL APPLICATION Instrumentation Amplifier R1 50k R2 5k – 1/2 LT1352 – VIN + R5 1.1k R3 5k Large-Signal Response R4 50k – 1/2 LT1352 VOUT + + GAIN = [R4/R3][1 + (1/2)(R2/R1 + R3/R4) + (R2 + R3)/R5] = 102 TRIM R5 FOR GAIN TRIM R1 FOR COMMON MODE REJECTION BW = 30kHz 1352/53 TA01 AV = –1 1352/53 TA02 1 LT1352/LT1353 W W U W ABSOLUTE MAXIMUM RATINGS Total Supply Voltage (V + to V –) .............................. 36V Differential Input Voltage ....................................... ±10V Input Voltage .......................................................... ±VS Output Short-Circuit Duration (Note 1) ........... Indefinite Operating Temperature Range ................ – 40°C to 85°C Specified Temperature Range ................ – 40°C to 85°C Maximum Junction Temperature (See Below) Plastic Package ............................................... 150°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C W U U PACKAGE/ORDER INFORMATION TOP VIEW OUT A 1 –IN A 2 8 V+ 7 OUT B ORDER PART NUMBER +IN A 3 B V– 4 6 –IN B 5 +IN B S8 PART MARKING S8 PACKAGE 8-LEAD PLASTIC SO 1352 A D +IN A 3 V+ 13 –IN D LT1353CS 12 +IN D 11 V – 4 +IN B 5 N8 PACKAGE 8-LEAD PDIP 14 OUT D OUT A 1 –IN A 2 LT1352CN8 LT1352CS8 A ORDER PART NUMBER TOP VIEW B C 10 +IN C –IN B 6 9 –IN C OUT B 7 8 OUT C S PACKAGE 14-LEAD PLASTIC SO TJMAX = 150°C, θJA = 130°C/ W (N8) TJMAX = 150°C, θJA = 190°C/ W (S8) TJMAX = 150°C, θJA = 150°C/ W Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS TA = 25°C, VCM = 0V unless otherwise noted. SYMBOL PARAMETER VOS Input Offset Voltage CONDITIONS ±15V ±5V ±2.5V TYP MAX 0.2 0.2 0.3 0.6 0.6 0.8 mV mV mV IOS Input Offset Current IB Input Bias Current ±2.5V to ±15V 5 15 nA ±2.5V to ±15V 20 50 nA en Input Noise Voltage f = 10kHz ±2.5V to ±15V 14 nV/√Hz in RIN Input Noise Current f = 10kHz ±2.5V to ±15V Input Resistance VCM = ±12V Differential CIN Input Capacitance ±15V Positive Input Voltage Range ±15V ±5V ±2.5V Negative Input Voltage Range ±15V ±5V ±2.5V CMRR Common Mode Rejection Ratio VCM = ±12V VCM = ±2.5V VCM = ±0.5V PSRR Power Supply Rejection Ratio VS = ±2.5V to ±15V 2 VSUPPLY ±15V ±15V ±15V ±5V ±2.5V MIN UNITS 0.5 pA/√Hz 300 600 20 MΩ MΩ 3 pF 12.0 2.5 0.5 13.5 3.5 1.0 V V V – 13.5 – 3.5 – 1.0 – 12.0 – 2.5 – 0.5 V V V 80 78 68 94 86 77 dB dB dB 90 106 dB LT1352/LT1353 ELECTRICAL CHARACTERISTICS TA = 25°C, VCM = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS VSUPPLY MIN TYP AVOL Large-Signal Voltage Gain VOUT IOUT VOUT = ±12V, RL = 5k VOUT = ±10V, RL = 2k VOUT = ±10V, RL = 1k VOUT = ±2.5V, RL = 5k VOUT = ±2 .5V, RL = 2k VOUT = ±2.5V, RL = 1k VOUT = ±1V, RL = 5k ±15V ±15V ±15V ±5V ±5V ±5V ±2.5V 40 30 20 30 25 15 20 80 60 40 60 50 30 40 V/mV V/mV V/mV V/mV V/mV V/mV V/mV Output Swing RL = 5k, VIN = ±10mV RL = 2k, VIN = ±10mV RL = 1k, VIN = ±10mV RL = 1k, VIN = ±10mV RL= 500Ω, VIN = ±10mV RL = 5k, VIN = ±10mV ±15V ±15V ±15V ±5V ±5V ±2.5V 13.5 13.4 13.0 3.5 3.4 1.3 14.0 13.8 13.4 4.0 3.8 1.7 ±V ±V ±V ±V ±V ±V Output Current VOUT = ±13V VOUT = ±3.4V ±15V ±5V 13.0 6.8 13.4 7.6 mA mA ISC Short-Circuit Current VOUT = 0V, VIN = ±3V ±15V 30 45 mA SR Slew Rate AV = – 1, RL = 5k (Note 2) ±15V ±5V 120 30 200 50 V/µs V/µs Full-Power Bandwidth 10V Peak (Note 3) 3V Peak (Note 3) ±15V ±5V 3.2 2.6 MHz MHz GBW Gain Bandwidth f = 200kHz, RL = 10k ±15V ± 5V ± 2.5V 3.0 2.7 2.5 MHz MHz MHz tr, tf Rise Time, Fall Time AV = 1, 10% to 90%, 0.1V ±15V ±5V 46 53 ns ns Overshoot AV = 1, 0.1V ±15V ±5V 13 16 % % Propagation Delay 50% VIN to 50% VOUT, 0.1V ±15V ±5V 41 52 ns ns ts Settling Time 10V Step, 0.1%, AV = – 1 10V Step, 0.01%, AV = – 1 5V Step, 0.1%, AV = – 1 5V Step, 0.01%, AV = – 1 ±15V ±15V ±5V ±5V 700 1250 950 1400 ns ns ns ns RO Output Resistance AV = 1, f = 20kHz ±15V 1.5 Ω Channel Separation VOUT = ±10V, RL = 2k ±15V 120 dB Supply Current Each Amplifier Each Amplifier ±15V ±5V IS 2.0 1.8 101 MAX UNITS 250 230 320 300 µA µA TYP MAX UNITS 0°C ≤ TA ≤ 70°C, VCM = 0V unless otherwise noted. SYMBOL PARAMETER VOS Input Offset Voltage Input VOS Drift CONDITIONS VSUPPLY MIN ±15V ±5V ±2.5V (Note 4) ±2.5V to ±15V 0.8 0.8 1.0 3 mV mV mV 8 µV/°C IOS Input Offset Current ±2.5V to ±15V 20 nA IB Input Bias Current ±2.5V to ±15V 75 nA 3 LT1352/LT1353 ELECTRICAL CHARACTERISTICS 0°C ≤ TA ≤ 70°C, VCM = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS VSUPPLY MIN CMRR Common Mode Rejection Ratio VCM = ±12V VCM = ±2.5V VCM = ±0.5V ±15V ±5V ±2.5V 78 77 67 dB dB dB PSRR Power Supply Rejection Ratio VS = ±2.5V to ±15V 89 dB AVOL Large-Signal Voltage Gain VOUT = ±12V, RL = 5k VOUT = ±10V, RL = 2k VOUT = ±2.5V, RL = 5k VOUT = ±2 .5V, RL = 2k VOUT = ±2.5V, RL = 1k VOUT = ±1V, RL = 5k ±15V ±15V ±5V ±5V ±5V ±2.5V 25 20 20 15 10 15 V/mV V/mV V/mV V/mV V/mV V/mV VOUT Output Swing RL = 5k, VIN = ±10mV RL = 2k, VIN = ±10mV RL = 1k, VIN = ±10mV RL = 1k, VIN = ±10mV RL= 500Ω, VIN = ±10mV RL = 5k, VIN = ±10mV ±15V ±15V ±15V ±5V ±5V ±2.5V 13.4 13.3 12.0 3.4 3.3 1.2 ±V ±V ±V ±V ±V ±V IOUT Output Current VOUT = ±12V VOUT = ±3.3V ±15V ±5V 12.0 6.6 mA mA ISC Short-Circuit Current VOUT = 0V, VIN = ±3V ±15V 24 mA SR Slew Rate AV = – 1, RL = 5k (Note 2) ±15V ±5V 100 21 V/µs V/µs GBW Gain Bandwidth f = 200kHz, RL = 10k ±15V ± 5V 1.8 1.6 MHz MHz Channel Separation VOUT = ±10V, RL = 2k ±15V 100 dB Supply Current Each Amplifier Each Amplifier ±15V ±5V IS TYP MAX UNITS 350 330 µA µA MAX UNITS – 40°C ≤ TA ≤ 85°C, VCM = 0V unless otherwise noted (Note 5). SYMBOL PARAMETER VOS Input Offset Voltage Input VOS Drift CONDITIONS VSUPPLY MIN TYP ±15V ±5V ±2.5V (Note 4) 1.0 1.0 1.2 ±2.5V to ±15V 3 8 mV mV mV µV/°C IOS Input Offset Current ±2.5V to ±15V 30 nA IB Input Bias Current ±2.5V to ±15V 100 nA CMRR Common Mode Rejection Ratio VCM = ±12V VCM = ±2.5V VCM = ±0.5V PSRR Power Supply Rejection Ratio VS = ±2.5V to ±15V AVOL Large-Signal Voltage Gain VOUT = ±12V, RL = 5k VOUT = ±10V, RL = 2k VOUT = ±2.5V, RL = 5k VOUT = ±2 .5V, RL = 2k VOUT = ±2.5V, RL = 1k VOUT = ±1V, RL = 5k 4 ±15V ±5V ±2.5V ±15V ±15V ±5V ±5V ±5V ±2.5V 76 76 66 dB dB dB 87 dB 20 15 15 10 8 10 V/mV V/mV V/mV V/mV V/mV V/mV LT1352/LT1353 ELECTRICAL CHARACTERISTICS – 40°C ≤ TA ≤ 85°C, VCM = 0V unless otherwise noted (Note 4). SYMBOL PARAMETER CONDITIONS VSUPPLY MIN VOUT Output Swing RL = 5k, VIN = ±10mV RL = 2k, VIN = ±10mV RL = 1k, VIN = ±10mV RL = 1k, VIN = ±10mV RL= 500Ω, VIN = ±10mV RL = 5k, VIN = ±10mV ±15V ±15V ±15V ±5V ±5V ±2.5V 13.3 13.2 10.0 3.3 3.2 1.1 ±V ±V ±V ±V ±V ±V IOUT Output Current VOUT = ±10V VOUT = ±3.2V ±15V ±5V 10.0 6.4 mA mA ISC Short-Circuit Current VOUT = 0V, VIN = ±3V ±15V 20 mA SR Slew Rate AV = – 1, RL = 5k (Note 2) ±15V ±5V 50 15 V/µs V/µs GBW Gain Bandwidth f = 200kHz, RL = 10k ±15V ± 5V 1.6 1.4 MHz MHz Channel Separation VOUT = ±10V, RL = 2k ±15V 99 Supply Current Each Amplifier Each Amplifier ±15V ±5V IS Note 1: A heat sink may be required to keep the junction temperature below absolute maximum when the output is shorted indefinitely. Note 2: Slew rate is measured between ±8V on the output with ±12V input for ±15V supplies and ±2V on the output with ±3V input for ±5V supplies. Note 3: Full-power bandwidth is calculated from the slew rate measurement: FPBW = (Slew Rate)/2πVP. TYP MAX UNITS dB µA µA 380 350 Note 4: This parameter is not 100% tested. Note 5: The LT1352/LT1353 are designed, characterized and expected to meet these extended temperature limits, but are not tested at – 40°C and 85°C. Guaranteed I grade parts are available, consult factory. U W TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Supply Voltage and Temperature Input Common Mode Range vs Supply Voltage V+ 350 30 TA = 25°C ∆VOS = 1mV – 0.5 125°C 250 25°C 200 – 55°C 150 TA = 25°C VS = ±15V –1.0 INPUT BIAS CURRENT (nA) 300 COMMON MODE RANGE (V) SUPPLY CURRENT PER AMPLIFIER (µA) Input Bias Current vs Input Common Mode Voltage –1.5 –2.0 2.0 1.5 1.0 20 IB = IB+ + IB– 2 10 0 –10 0.5 100 V– 0 10 5 15 SUPPLY VOLTAGE (± V) 20 1352/53 G01 0 15 10 5 SUPPLY VOLTAGE (± V) 20 1352/53 G02 –20 –15 10 –5 0 5 –10 INPUT COMMON MODE VOLTAGE (V) 15 1352/53 G03 5 LT1352/LT1353 U W TYPICAL PERFORMANCE CHARACTERISTICS 100 VS = ±15V IB+ + IB– IB = 2 INPUT VOLTAGE NOISE (nV/√Hz) 32 Open-Loop Gain vs Resistive Load 28 24 20 16 12 8 110 10 TA = 25°C TA = 25°C VS = ±15V AV = 101 RS = 100k INPUT CURRENT NOISE (pA/√Hz) INPUT BIAS CURRENT (nA) 36 Input Noise Spectral Density en 1 10 in VS = ±15V 100 OPEN-LOOP GAIN (dB) Input Bias Current vs Temperature 40 VS = ±5V 90 80 70 4 50 25 0 75 TEMPERATURE (°C) 100 125 1 10 1k 100 FREQUENCY (Hz) 1352/53 G04 97 96 95 V+ 50 25 75 0 TEMPERATURE (°C) 100 RL = 1k –2 –3 TA = 25°C VIN = ±10mV 3 RL = 1k 2 RL = 2k 0 5 10 VS = ±15V 10 8 2 0 –2 –4 10mV –8 125 1352/53 G10 6 1mV VS = ±15V AV = 1 OUTPUT FILTER: 1.6MHz LPF –10 100 – 40°C – 40°C 25°C 85°C 15 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 SETTLING TIME (µs) 1352/53 G11 20 6 1mV 4 –6 30 25°C 85°C 1.0 8 OUTPUT STEP (V) OUTPUT STEP (V) SOURCE 50 25 75 0 TEMPERATURE (°C) 1.5 10 10mV 35 25 –50 –25 2.0 – 40°C 85°C Settling Time vs Output Step (Inverting) 6 40 –2.0 25°C 1352/53 G09 55 45 – 40°C –1.5 Settling Time vs Output Step (Noninverting) SINK 85°C 1352/53 G08 Output Short-Circuit Current vs Temperature 50 25°C –1.0 V– –20 –15 –10 – 5 0 10 5 OUTPUT CURRENT (mA) 20 15 SUPPLY VOLTAGE (V) VS = ±5V VIN = 10mV 0.5 V– 125 1352/53 G07 OUTPUT SHORT-CIRCUIT CURRENT (mA) – 0.5 RL = 2k 1 94 –50 –25 60 Output Voltage Swing vs Load Current –1 98 10k 1352/53 G06 V+ OUTPUT VOLTAGE SWING (V) OPEN-LOOP GAIN (dB) 99 1k LOAD RESISTANCE (Ω) Output Voltage Swing vs Supply Voltage VS = ±15V VO = ±12V RL = 5k 100 10 1352/53 G05 Open-Loop Gain vs Temperature 100 60 0.1 10k 1 OUTPUT VOLTAGE SWING (V) 0 –50 –25 4 2 10mV 1mV 0 –2 –4 –6 –8 10mV VS = ±15V AV = –1 RG = RF = 2k CF = 5pF RL = 2k 1mV –10 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 SETTLING TIME (µs) 1352/53 G12 LT1352/LT1353 U W TYPICAL PERFORMANCE CHARACTERISTICS 60 VS = ±5V 40 30 GAIN 20 20 10 0 0 –20 –10 –40 100M 1k 10k 100k 1M FREQUENCY (Hz) 10M 6 AV = 100 AV = 10 10 1 0.1 10k 1k 100k 1M FREQUENCY (Hz) 4.00 VS = ±5V 46 3 3.75 PHASE MARGIN 44 10M 42 3.25 40 38 2.00 –50 –25 5 TA = 25°C AV = 1 RL = 5k 3 2 1 0 –1 VS = ±5V 34 –3 32 –4 ±15V ±5V ±2.5V –2 3.75 44 3.50 42 3.25 40 3.00 38 36 2.75 GAIN BANDWIDTH 2.50 34 32 2.25 30 2.00 0 15 10 5 SUPPLY VOLTAGE (± V) 20 1352/53 G19 POWER SUPPLY REJECTION RATIO (dB) 46 PHASE MARGIN PHASE MARGIN (DEG) GAIN BANDWIDTH (MHz) 120 48 4.00 –2 ±15V ±5V ±2.5V –5 10k 10M 100k 1M FREQUENCY (Hz) 10M 1352/53 G18 Power Supply Rejection Ratio vs Frequency 50 TA = 25°C –1 1352/53 G17 Gain Bandwidth and Phase Margin vs Supply Voltage 4.25 0 –3 100k 1M FREQUENCY (Hz) 1352/53 G16 4.50 TA = 25°C AV = –1 RF = RG = 5k –4 –5 10k 30 125 4 1 36 100 10M Frequency Response vs Supply Voltage (AV = – 1) 2 VS = ±15V 50 25 0 75 TEMPERATURE (°C) 100k 1M FREQUENCY (Hz) 1352/53 G15 GAIN (dB) GAIN BANDWIDTH (MHz) 3.50 GAIN (dB) 4 PHASE MARGIN (DEG) 5 48 2.25 –10 10k Frequency Response vs Supply Voltage (AV = 1) 50 2.50 C = 10pF –2 1352/53 G14 VS = ±15V 2.75 0 –8 0.01 4.25 3.00 C = 1000pF 2 –4 Gain Bandwidth and Phase Margin vs Temperature GAIN BANDWIDTH C = 5000pF C = 500pF C = 100pF –6 1352/53 G13 4.50 TA = 25°C VS = ±15V AV = –1 RFB = RG = 5k 4 AV = 1 GAIN (dB) VS = ±5V 8 100 80 VS = ±15V PHASE (DEG) 40 100 Common Mode Rejection Ratio vs Frequency TA = 25°C VS = ±15V 100 80 – PSRR = +PSRR 60 40 20 0 10 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 1352/53 G20 120 COMMON MODE REJECTION RATIO (dB) VS = ±15V TA = 25°C VS = ±15V OUTPUT IMPEDANCE (Ω) PHASE 50 GAIN (dB) TA = 25°C AV = –1 RF = RG = 5k 10 1000 120 70 60 Frequency Response vs Capacitive Load Output Impedance vs Frequency Gain and Phase vs Frequency 100 TA = 25°C VS = ±15V 80 60 40 20 0 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 1352/53 G21 7 LT1352/LT1353 U W TYPICAL PERFORMANCE CHARACTERISTICS Slew Rate vs Supply Voltage TA = 25°C AV = –1 RF = RG = 5k SR = (SR+ + SR – )/2 Slew Rate vs Input Level 150 VS = ±15V 150 100 VS = ±5V 50 50 TA = 25°C VS = ±15V AV = –1 RFB = RG = 5k SR = (SR+ + SR –)/2 175 SLEW RATE (V/µs) 100 200 AV = –1 RF = RG = RL = 5k SR = (SR+ + SR – )/2 200 SLEW RATE (V/µs) 150 SLEW RATE (V/µs) Slew Rate vs Temperature 250 200 125 100 75 50 25 0 0 0 –50 –25 15 5 10 SUPPLY VOLTAGE (±V) 50 0 75 25 TEMPERATURE (°C) 1352/53 G22 AV = 1 20 15 10 5 AV = 1 0.001 10 100 1k 10k FREQUENCY (Hz) 100k FREQUENCY (Hz) – 50 – 60 – 60 –70 TA = 25°C AV = 1 RL = 1k VIN = 15dBm 90 80 –70 – 80 – 90 1352/53 G28 –120 100 TA = 25°C VS = ±15V RL = 5k 70 AV = 1 60 50 40 AV = –1 30 20 –110 FREQUENCY (Hz) 1M Capacitive Load Handling – 80 1M 100k FREQUENCY (Hz) 100 –100 2ND HARMONIC VS = ± 5V RL = 5k THD = 1% 1352/53 G27 OVERSHOOT (%) VS = ±15V AV = 1 RL = 5k VO = 2VP-P CROSSTALK (dB) HARMONIC DISTORTION (dB) 4 3 Crosstalk vs Frequency 3RD HARMONIC AV = –1 5 0 10k 1M – 40 – 50 AV = 1 6 1352/53 G26 2nd and 3rd Harmonic Distortion vs Frequency 8 7 1 1352/53 G25 – 90 100k 8 2 VS = ±15V RL = 5k THD = 1% 0 10k 100k OUTPUT VOLTAGE (VP-P) OUTPUT VOLTAGE (VP-P) TOTAL HARMONIC DISTORTION (%) AV = –1 24 9 25 0.01 20 10 AV = –1 0.1 8 16 12 INPUT LEVEL (VP-P) Undistorted Output Swing vs Frequency (±5V) 30 TA = 25°C VS = ±15V RL = 5k VO = 2VP-P 4 0 1352/53 G24 Undistorted Output Swing vs Frequency (±15V) 1 – 40 0 125 1352/53 G23 Total Harmonic Distortion vs Frequency – 30 100 10 1k 10k 100k FREQUENCY (Hz) 1M 10M 1352/53 G29 0 10p 100p 1n 10n 0.1µ CAPACITIVE LOAD (F) 1µ 1352/53 G30 LT1352/LT1353 U W TYPICAL PERFORMANCE CHARACTERISTICS Small-Signal Transient (AV = 1) Small-Signal Transient (AV = – 1) 1352/53 G31 Small-Signal Transient (AV = – 1, CL = 1000pF) 1352/53 G32 Large-Signal Transient (AV = – 1) Large-Signal Transient (AV = 1) 1352/53 G34 1352/53 G33 Large-Signal Transient (AV = 1, CL = 10,000pF) 1352/53 G35 1352/53 G36 U W U U APPLICATIONS INFORMATION Layout and Passive Components Capacitive Loading The LT1352/LT1353 amplifiers are easy to use and tolerant of less than ideal layouts. For maximum performance (for example, fast 0.01% 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 LT1352/LT1353 are stable with any capacitive load. 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. Graphs of Frequency Response vs Capacitive Load, Capacitive Load Handling and the transient response photos clearly show these effects. The parallel combination of the feedback resistor and gain setting resistor on the inverting input can combine with the input capacitance to form a pole which can cause peaking or even oscillations. If feedback resistors greater than 10k are used, a parallel capacitor of value, C F > (RG)(CIN/RF), should be used to cancel the input pole and optimize dynamic performance. For applications where the DC noise gain is one 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 as shown in the Typical Applications section. Input Considerations Each of the LT1352/LT1353 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 NPN to PNP beta matching and is well controlled. The use of balanced source resistance at each input is recom- 9 LT1352/LT1353 U W U U APPLICATIONS INFORMATION mended for applications where DC accuracy must be maximized. The inputs can withstand differential input voltages of up to 10V without damage and need no clamping or source resistance for protection. Differential inputs generate large supply currents (up to 40mA) as required for high slew rates. Typically power dissipation does not significantly increase because of the low duty cycle of the transient inputs. If the device is used as a comparator with sustained differential inputs, excessive power dissipation may result. Circuit Operation The LT1352/LT1353 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 R1, a 1k resistor. The input voltage appears across the resistor generating currents which are mirrored into the high impedance node and compensation capacitor CT. Complementary followers form an output stage which buffers the gain node from the load. The output devices Q19 and Q22 are connected to form a composite PNP and a composite NPN. 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 high impedance 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. For example, a 10V output step in a gain of 10 has only a 1V input step whereas the same output step in unity gain has a 10 times greater input step. The graph Slew Rate vs Input Level illustrates this relationship. In higher gain configurations the largesignal performance and the small-signal performance both look like a single pole response. 10 Capacitive load compensation is provided by the RC, CC network which is bootstrapped across the output stage. When the amplifier is driving a light load the network has no effect. When driving a capacitive load (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 and a zero is created by the RC combination, both of which improve the phase margin. The design ensures that even for very large load capacitances, the total phase lag can never exceed 180 degrees (zero phase margin) and the amplifier remains stable. Power Dissipation The LT1352/LT1353 combine high speed and large output drive in small packages. Because of the wide supply voltage range, it is possible to exceed the maximum junction temperature of 150°C under certain conditions. Maximum junction temperature TJ is calculated from the ambient temperature TA and power dissipation PD as follows: LT1352CN8: TJ = TA + (PD)(130°C/W) LT1352CS8: TJ = TA + (PD)(190°C/W) LT1353CS: TJ = TA + (PD)(150°C/W) Worst-case power dissipation occurs at the maximum supply current and 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 PD(MAX) is: PD(MAX) = (V + – V –)(IS(MAX)) + (V +/2)2/RL or (V + – V –)(IS(MAX)) + (V + – VMAX)(IMAX) Example: LT1353 in S14 at 85°C, VS = ±15V, RL = 500Ω, VOUT = ±5V (±10mA) PD(MAX) = (30V)(380µA) + (15V – 5V)(10mA) = 111mW TJ = 85°C + (4)(111mW)(150°C/W) = 152°C LT1352/LT1353 W W SI PLIFIED SCHE ATIC V+ R2 Q11 Q10 Q12 R3 Q21 Q20 C1 R6 Q9 –IN Q7 R1 Q3 1k Q5 Q17 Q1 Q2 Q6 Q8 Q19 CC RC +IN OUTPUT Q18 Q4 R7 Q22 Q13 C2 CT Q15 Q14 Q23 Q16 Q24 R4 R5 V– 1352/53 SS U TYPICAL APPLICATIONS 400kHz Photodiode Preamp with 10kHz Highpass Loop DAC I-to-V Converter 1N5712 10pF 10k 5k – 1/2 LT1352 565A TYPE – VOUT + BPV22NF 5k V VOS + IOS (5kΩ) + OUT < 0.5LSB AVOL 1/2 LT1352 1.5k VOUT + 10k 1352/53 TA03 1/2 LT1352 10nF – 12 + DAC INPUTS 10nF 10k 1352/53 TA05 20kHz, 4th Order Butterworth Filter 4.64k 5.49k 470pF 220pF 4.64k 13.3k VIN 2200pF – 1/2 LT1352 + 5.49k 11.3k 4700pF – 1/2 LT1352 VOUT + 1352/53 TA04 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 11 LT1352/LT1353 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.300 – 0.325 (7.620 – 8.255) ( 0.130 ± 0.005 (3.302 ± 0.127) 0.045 – 0.065 (1.143 – 1.651) 0.065 (1.651) TYP 0.009 – 0.015 (0.229 – 0.381) ) 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.125 (3.175) MIN 0.018 ± 0.003 (0.457 ± 0.076) 0.005 (0.127) MIN 0.100 ± 0.010 (2.540 ± 0.254) +0.025 0.325 –0.015 +0.635 8.255 –0.381 0.400* (10.160) MAX 0.015 (0.380) MIN *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) *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 7 8 5 6 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 3 2 4 S Package 14-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.337 – 0.344* (8.560 – 8.738) 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.004 – 0.010 (0.101 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 14 13 12 11 10 9 8 0° – 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) 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 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157** (3.810 – 3.988) 1 2 3 4 5 6 7 RELATED PARTS PART NUMBER LT1351 LT1354/55/56 12 DESCRIPTION 250µA, 3MHz, 200V/µs Op Amp Single/Dual/Quad 1mA, 12MHz, 400V/µs Op Amp Linear Technology Corporation COMMENTS Good DC Precision, C-Load Stable, Power Saving Shutdown Good DC Precision, Stable with All Capacitive Loads LT/GP 0796 7K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● TELEX: 499-3977 LINEAR TECHNOLOGY CORPORATION 1996